The Widgetator: Newsletter Challenge (08/07/07)

"the Widgetator^TM assembly, which will only widgetize properly if two components are soldered or brazed and two components are welded. Brazing two components will enable high speed widgetation."

A very strange set of components and means of fastening parts together.

No problems with soldering/brazing two non-ferrous or even ferrous components.

That leaves two components to be welded together. This means using a filler material of essentially the same composition or nature of the components. Only materials I can think of are plastic components that can be welded with a hot gas gun and filler rod of the same composition .

Solders have a liquidus below the base metal, while welding alloys fuse with the base metal.

I think the question is specific in the components being some sort of metal so we can rule out plastics.

I may be missing something complex, but I'm a simple-minded person (how many different ways can YOU arrange one neuron?). 4043 filler for aluminum can be used for both brazing and welding.

Tom

I am not sure if TVP45 is quite right. 4043 may be used for brazing if it is brazing aluminum alloys with a higher melting point, or it may be used for welding aluminum alloys with a compatible lower melting point.

If I understood the question correctly, all the components would be made out of the same base material, so this would not be possible. If the base materials could be different alloys, then he would be correct.

Here is another alternative:

If your filler material is a matrix of two metals and one is the same as your base metal (or at least compatible for welding) and the other is a lower melting temperature metal which is excellent for brazing the base metals together, than your joint will become brazed or welded depending on what temperature is used to melt the filler material. If the low, brazing temperature is selected than the brazing metal will melt and bond the two components and the remaining solid filler material. If the temperature is raised to the welding temperature, the weld compatible filler will also melt and fuse with the components, creating a welded joint.

This can be quiet easily done using powdered metal technology to create your filler material with the two (or more) metals. I am not a metallurgist, nor a welding engineer, so I really do not know if such a material is readily available on the market. The filler could be either in easily applied paste form (usually with an organic binder) or as a brittle solid by compression and partial sintering of the metal powders. Depending on the part geometry, the solid filler could be obtained as a pre-form, such as a ring, disc, etc. to closely match the parts.

Hello StL,

If it is as you say and the same two components might be either welded or brazed, then my answer is not correct, but I read it as 2 components will be brazed AND 2 components will be welded and only the filler is common. We need some clarification.

Tom

Wait a minute. I did not say that the same two components might be either welded or brazed (although that would be a possibility). In fact, I never mentioned the quantity of components, only that the question implied they would all be made of the same base material. In fact it is quite possible that the assembly is composed of four different components. If two of the components which need to be joined are the same or compatible materials and different from the material of the other two, you may be correct. If all are the same materials, as I inferred, then 4031 would not work for both brazing and soldering. However my process could work in that case, if the right multi-metal filler material could be found or made as I described.

We do agree, clarification is needed.

StL,

Sorry, I didn't mean to put words in your mouth. And, I have no great brief for 4043; a note on that just happened to be pinned to my cube wall as I was reading this. There should be many such fillers, but all would sort of have the same characteristic. I suppose I might try to think of one where the solidus/liquidus can be moved by something other than heat. Interesting problem, but still not clear to me. mmmm, maybe the process alters the liquidus temperature?

Tom

I'm no expert (as if you didn't know), but isn't there a problem with mixtures that energy considerations tend to cause the lowest temperature mix (the eutectic) to remain separate - or to separate again during cooling or annealing. That would make it hard to avoid having regions of low temperature melt within the joint, whatever the maximum joining temperature. In any case, your ingenious answer is disallowed by the question, which specifies "a single alloy" rather than a "single product" or "single mixture"

So, with regret, I incline to the view that the question requires that the difference is in the materials to be joined, rather than in the behaviour of the jointing medium. [I hope I'm wrong, because in that case I, along with many other CR4 users, would learn something unexpected.] My only other (very tentative) thought (I don't really believe in it) is that the soldering material may be useful in very small quantities for welding, where its effect is as a surface cleaner at the beginning, becoming dispersed to negligible concentrations during the welding.

Fyz

Fyz, I try not to get hung up on words that might be misapplied. While I agree that strictly speaking, a mixture of powdered metals may not qualify as a true alloy in metallurgical terms, the writer may not have intended to be so restrictive. His use of the term "alloy" may not be as limiting as you might think. He did say that "Timothy needs one soldering and welding joint material for quantity, discount purchasing."

We also have my old standby, Merriam-Webster, which says:

~~~~~~~~~~~~~~~~~

Main Entry: ¹al·loy
Pronunciation: 'a-"loi also &-'loi
Function: noun
Etymology: French aloi, from Old French alei, from aleir to combine, from Latin alligare to bind -- more at ALLY
1 : the degree of mixture with base metals : FINENESS
2 : a substance composed of two or more metals or of a metal and a nonmetal intimately united usually by being fused together and dissolving in each other when molten; also : the state of union of the components
3 a : an admixture that lessens value b : an impairing alien element
4 : a compound, mixture, or union of different things <an ethnic alloy of many peoples>
5 archaic : a metal mixed with a more valuable metal to give durability or some other desired quality

~~~~~~~~~~~~~

While sense #2 does contain the dissolving in each other requirement that does not necessarily happen when some powdered metals are sintered, and would therefore be more restrictive, sense #4 could also apply without such a limiting quality. Indeed, we sometimes talk about "polymer alloys" that are not even metals!

Wikipedia goes even further, describing alloys as homogeneous mixtures, which includes true solutions as well as colloidal and other suspensions. While my "powdered metal" material may not quite meet that definition either, being more of a heterogeneous mixture, like granite, the dispersion is typically quite fine and would approach that of a suspension. When sintered, there may even be some fusing and solutions of the two metals, especially at particle boundaries, not unlike the grain boundaries in a true alloy.

Perhaps technology has caught up with and even passed our conventional thinking!

And, if it turns out that his intention was for the pairs of components to be of different base metals, making your interpretation correct, then this "challenge" truly was TOO EASY!

I don't know much about welding or brazing, and a little about soldering, so I can't comment in depth on which materials to use.

The one thing I do know is that that any joint in a machine needs to be able to withstand any stresses, strains, and pressures it may be subjected to. This seems to be the fundamental issue in determining the type of joint, the method of joining, and the materials used.

This is the only postive contribution I can make, or maybe I'm just stirring the pot again. I'll sit back, read the comments, and try to learn something. If this thread strays off topic, I might jump back in.

"Timothy needs one soldering and welding joint material for quantity, discount purchasing. Solders have a liquidus below the base metal, while welding alloys fuse with the base metal."

Solders and brazing alloy bond or adhere to the surfce of the metal they are applied to with a strong adhesive like bond.

Welding alloys become an integral part of the parts to be welded in the weld zone thus making the two parts one, as if originally made in one solid piece.

"Can he find a single alloy to solder and weld his assembly?"

Unless there is some radically new in the techniques my conclusion is that there is NO ONE single alloy to both solder and weld an assembly of parts composed of only one material.

As I read the original challenge (several times), there is nothing that says the assembly must be made of one material, only that the solder/weld filler must be one alloy. As I interpret the challenge, the task is to find two metals or alloys, one of which has a liquidus essentially the same as the solder/braze so two or more parts of that material can be welded using that material as weld filler, and another which has a higher liquidus, so two or more parts of that material can be soldered or brazed together in order to wigetize correctly without deforming due to the braze temperature.

There are lots of class 1 and 2 , or class 2 and 3, alloys of copper that could fit the bill, with an appropriate braze material.

I interpret this as you have, namely that the assembly can be made of more than one material. In that case, ordinary bronze brazing rod welds to itself and to other brass and bronze alloys. It can also be used to braze steel.

I wonder if the question was intended to be that simple?

How about three metals that melt at descending rates! the highest melting metal is the material to be welded onto, the middle is the filler rod, and the lowest is the solder!

for example:- copper(1083^oC)-brass(927^oC)-bronze(913^oC) as stated above or

aluminium(659^oC)-magnesium(651^oC)-zinc(419^oC)

I think that last one may work but please correct me if the zinc is too volatile!

I wouldn't worry about the zinc being too volatile, but watch out for magnesium! It burns in air extremely quickly with a lot of heat liberated. That is why sticks of magnesium are often used as fire-starting "sparkers", which make showers of hot sparks when scraped quickly by a steel edge.

From the Wikipedia: "Magnesium is a highly flammable metal, but while it is easy to ignite when powdered or shaved into thin strips, it is difficult to ignite in mass or bulk. Once ignited it is difficult to extinguish, being able to burn in both nitrogen (forming magnesium nitride), and carbon dioxide (forming magnesium oxide and carbon).

And this: "Magnesium metal and alloys are highly flammable in their pure form when molten, as a powder, or in ribbon form."

You start melting magnesium in a normal atmosphere (with nitrogen, oxygen and low pressure) and you better duck and cover! Once burning only dry chemical extinguishers or sand will put out the fire. Carbon dioxide or water only makes it burn hotter!

Nice thought - perhaps we solder in an inert or reducing atmosphere, and weld initially in an oxidising atmosphere, converting to reducing once we reach temperature. The solder provides the heat for welding and burns away. I'm not certain of the effect of the residual metallic oxide - perhaps it forms some sort of nucleation point for the weld??

Isn't the idea of a "flux" in resistance welding to create a CO2 gas that protects the molten metals from oxide contaminants?

As I said in my first contribution to this thread - I'm no expert (nothing new there). But I believe the situation to be as follows (taking Mg as the example):

Flux reacts with the oxygen in the atmosphere and also with metallic oxides so that the solder and/or materials to be joined remain metallic. The oxygen is sometimes, but not always, combined as CO2. Not all solders contain fluxes - fluxless soldering and welding are sometimes carried out in forming gas (mixture - typically 8-10%H2 in N2). High-Mg solders would normally be used with forming gas, because any flux for Mg would have to react even more strongly with O2 than the Mg itself. Anything that reacts so strongly with O2 that it 'reduces' the welding materials could perhaps be regarded as a flux? So the question is whether the presence of magnesium oxide would spoil the weld integrity.

The theory sounds plausible. Like I said, I only have distant memories of one year of high school welding class, so I'm no expert either.

So what if instead of Mg metal, which already has some O in it, a Mg salt such as MgNH4PO4 was used instead? The Ammonia gas blanket would readily reduce O with the moisture in the air to form the hydroxide. Any gas I can think of to do the job would be either explosive or poisonous, so I'd make sure Timothy pays in cash up front for the consultation.

This is fast turning me into a cowering wreck... (and if I was the consultant, and it was the same materials being welded as soldered, I'd probably charge handsomely to advise TiMoThY* to buy different materials for the two processes, rather than buying the more expensive material to cover both and compromising his process flow, etc.)

Fyz

*Surely not intended to be some kind of clue?

"TiMoThY*"

"*Surely not intended to be some kind of clue?"

Hmmm, Titanium-Molybdenum-Thorium-Yttrium brazing / welding material?

Naaaaaaaahhhh!!!! Sounds more like some kind of Super Power Laser Crystal! But, then, Fyz, you should know more about that!

ROFL

Yes, it seems most unlikely - particularly as there is no eutectic composition for TiM. But the lasers would need a crystalline (e.g. garnet) or glass host - my wife always preferred the former.

Some of the answers sound more expensive than if the owner bit the bullet and bought two materials. Maybe he needs an accountant rather than an engineer. Besides - Everyone knows he'll never get a widgetator to widgetize. They can only Widgetate to achieve high speed widgetation.

Here's another less elegent solution: Because the question is looking for "a single alloy" to do the two fusions, rather than one product (i.e. specific welding /brazing rod). If the brazing was done with a specific alloy - drawn very thin - 32 guage copper wire for example is rated for 0.091 Amps Max. The welding is done with the same alloy at 0000 guage which could handle 302 Amps if it was copper. Could that work?

If we're going to go all pedantic, shouldn't it be a widgitor, being something that widges? (Widgate would be some kind of scandal, I think)?

Welding might work if the weld temperature was below the melt temperature of copper; this might even be usable for soldering/brazing if the the widget material and copper can form a eutectic alloy - but you'd have to find a way to stop the alloy forming when you were trying to weld. There's still the little problem of needing two ordering codes.

In my experience, it's usually the accountant who suggests this sort of thing - and the engineers who try and fail to stop it.

I can say that, because I'm not qualified to call myself a nengineer.

Fyz

The hair on the back of my neck stands up when i hear:

"The accountants in head office have come up with an idea"

If we're going to go all pedantic, shouldn't it be a widgitor, being something that widges? (Widgate would be some kind of scandal, I think)?

No, I think he is using these fictitious terms correctly. If one already has a widget that works improperly, i.e. it cannot be widgetized or widgetated by hand, then you need a Widgetator to get it to operate properly. By that I mean that the Widgetator would widgetate the widget, either after first widgetizing itself, if that is necessary, or also having the capability of widgetizing the widget, which might be a secondary function (see previous explanation in #48 below if you are confused. I know I am! )

Since our military uses so many widgets already, we desperately need a reliable High-speed Widgetator to support our troops in the field. The old low-speed widgetators left over from Viet Nam just can't do the job with today's high-tech, solid-state, software-defined, micro-processor based, user-friendly electronic widgetry. We need a Widgetator for this century, not the last! It needs to be so easy to operate, "A Caveman could do it!".

The Chinese are working very hard on a rice-based high-speed widgetator, and if they get theirs working first, with their pricing structure, well, there goes our European market, not to mention the Middle East, Asia and Africa! Of course the Aussies will buy our Widgetator over the Chinese, because they'll be able to "pump it up" and get at least 50% more widgetation than spec. Can't do that with Chinese Rice Widgetators! Canadians will buy them too, taking advantage of NAFTA. The Latinos in the rest of our hemisphere will probably buy our Widgetators also, because our instruction manuals will be bi-lingual and actually make sense in translation, unlike those of the Chinese!

Hard to say about the Brits, though. Some of them will probably favor the US-made Widgetator, despite the higher initial investment, but the rest will buy the Chinese version anyway due to the very low price, even though it will probably quit on them in half the time. Remember the old Latin saying, "Tempus Widgits"! (I really don't know what that means! )

I'm glad you put the global widgetry contraversy in proper prospective StL

Don't worry about the brits, they're still working on central heating, dental hygiene, and how to cook a roast.

When it comes to roast-beef, we're perfectionists, and will continue working on that until BSE wipes out the rest of our cattle. Regarding the others, we are currently widgetisating our (water-filled) radiators, in the hope that a little extra complexity will allow them to work properly; but our teeth are so crooked that we can't get the hygiene right even using electric toothbrushes, floss, and toothpicks, despite backing them up with quarterly visits to the dental hygienist.

Fyz

"but our teeth are so crooked that we can't get the hygiene right"

Its not your fault, Fyz. It's genetic. (Isn't everything?) The English just lack the Dental Hy gene!

ROFL

I thought it took two to make a brace.

Fyz

You mean like a "brace of pistols"? There you go, shooting your mouth off again!

Or, does it mean the tool, like in a brace and bit, where you bit off a bit more than you could chew with your crooked teeth?

ROFL

Well, brace up, good man, and let's have a bracer. God Save the Queen!

Last time I shot my mouth off, I lost what were left of my teeth (there are still a few on the right however).

As you surmised, it takes a brace of correct jeans if the dominant tooth-genie is awkward. When I was a kid a couple of centuries back, I was told that toof-straightening was merely cosmetic. Now I know better - but it's still not common practice over here.

"Last time I shot my mouth off, I lost what were left of my teeth (there are still a few on the right however)."

Ah, a jawbone for the Conservatives! Is that a kind of Tory mouthpiece?

Somebody, STOP ME! I am laughing so hard it hurts!

More sheep vs goats - I think I'll stay clear of putty politics for now. (I'm told foot-in-mouth disease is not normally useful in that arena).

Have you considered dental amalgam for the solder/weld compound?

By the way, I just remembered that we used to use solder pastes for hybrid microcircuits etc. that were filled with metallic balls (like I speak) to space legless (yep, I've been at that again) surface-mount components from the substrates. I believe the applications were for ultra-clean product (so you could clean and inspect between the package and the substrate); they were also used when the package was a little bit too large for the intrinsic materials to relieve the strains due to differential thermal expansion. That sounds rather like the sort of material you were postulating - albeit for an entirely different reason.

Sorry Fyz - The question does mention specifically "alloy". Dental amalgam is at best a mixture by definition, and by some conventions a colloid. Although if Hg Ag Sn Cu Zn Cd In Pd Pb aren't somewhere in the answer, I would be surprised.

This was intended as a slightly humorous reference to STL's proposal (post #4) to use a soldering alloy that included particles of an undissolved metal. That is indeed a mixture, but it includes at least one alloy. In view of the laxity of previous challenge answers, I think STL is well justified in allowing the concept to be extended - my bigger doubt is whether the physical principle he postulates could work.

Unless you know different, a true amalgam would be a metal dissolved in mercury. To my way of thinking, this is just a molten alloy. I'd go further - many alloys can separate (at temperatures above the eutectic point but below the melt for the specific composition) into a mixture of molten material and solid. In this respect, they are not that dissimilar to dental amalgam - indeed, I thought that the the whole point of dental amalgam is that once in place it interdiffuses to form an alloy (although admittedly the structure is not very uniform).

______________________________

Of course, I'm no expert (nothing new there)

Guys! Don't get hung up on semantics. Although the Challenge creator uses the word "alloy" in the final form of the question at the end, he refers to it as a "soldering and welding joint material" two sentences earlier. What if he had said "filler metal" instead of "alloy"?

I do not believe any right-thinking person would deliberately rule out a suitable material simply because it did not fit the very strict metallurgical definition of an "alloy".

It will probably be a moot point, as the official "right answer" will turn out to be, as several other have inferred, based on the components being of somewhat different materials, with differing melting points, and therefore providing a too easy answer. But if I am right, and the inference is for all components to be of the same "base metal", requiring a multi-phased material with different melting points, then we shall have to re-examine his use of the word "alloy".

Or perhaps there is something to that anode/cathode hotter/colder solution proposed be "cuznmonkey" in #29. Sounds feasible, and could work on components made from all the same "base metal", but then the issue really is not the material, but the process, which makes the question somewhat misleading....or was that the point?

ok then - help me out here. By the definitions given, if component A and B are both made from Ag, Cu, Sn, etc in some appreciable concentration, and mercury is added, would the resulting amalgam not fuse the parts together similar to welding? i.e. the component material becomes an alloy with the mercury? Then all we would have to do is to figure out a way to braze with it.

Those would be might expensive widgets if they were composed of Silver, Copper, and Tin in a composition similar to dental amalgam. And they would also be very soft, not having much strength, which I think would be a requirement for High Speed Widgetation! <grin>

Wikipedia offers this: In a press release the ADA wrote.... "dental amalgam contains elemental mercury combined with other metals such as silver, copper, tin and zinc to form a safe, stable alloy."

At least the ADA thinks it is an alloy! I would concur, since the mercury dissolves the other metals and thus makes a non-homogeneous mixture into a homogeneous solid solution. Could be very expensive as a filler metal though, not to mention the headaches the manufacturer would face from OSHA using Hg in their process.

The powdered metal process in comparison would provide for extremely small particle size without resorting to a hazardous metal like mercury to dissolve the other components. Whether the base materials were all alike or whether they were different, if the PM mixture contain both brazing and welding alloys, the higher temp welding alloys would serve merely as solid filler material during the brazing process, flowing with the liquid brazing alloy and strengthening the brazing material, as glass fibers and mineral fillers do in plastic resins used for injection molding.

Then if the same mixture is used for for welding, the welding alloy would melt as well and fuse with the compatible base metals. On cooling the brazing alloy should remain dispersed through out the weld, only examination of the microstructure would reveal its existence. This weld might be somewhat weaker than one using pure welding alloy, but it could still meet the strength requirement. Other alloys might also form within the weld which included the brazing metal and the base and weld alloys, since all would be molten. Since the brazing alloy remains liquid longer on cooling than the welding alloy, it might not remain concentrated in the critical, high pressure contact area, but flow out under pressure and be ground off (or not) later when the weld was dressed, but in any case, the weld could be made sufficiently strong to function as required.

hmmm that sounds reasonable. one further - if the PM mixture had a brazing material such that its liquid form could disolve the welding material (like molten cryolite Na₃AlF₆ disolves Alumina) that should satisfy all the information???

an Al/Cryolyte material heated to 1000c would melt the cryolyte and disolve the Al. This would be the brazing medium as long as the component's MP is greater than 1000. The Al then would be the welding material fusing with the components and using the cryolite as a flux.

Of course the Al/Cryolite is just a "for instance". The actual alloy used would have to be much more robust.

Firstly, I do not think that using the same alloy in two different forms will save much money, and that is clearly the goal, since usually companies offer discounts for bulk purchasing of a single "product". Also, handling and storage solutions become simpler (no redundancy of equipment, etc.) with only one product.

Secondly, perhaps he needs the Widgetator to "widgetize" in preparation to widgetate, and achieve high speed widgetation! Did you ever think of that? Huh? Didja? Kind of like having to prime (verb) a pump (noun) before you can pump (verb)with it.

Another possibility is that "widgetization" is a secondary function for the Widgetator, which primarily is used for "widgetation". So don't give me this "Everyone knows" crap. Maybe his design is the first auto-widgetizing High Speed Widgetator! Wow, what a breakthrough!

Well, my spies seem to have found a mock-up of Timothy's competition. This "Super-Widgitator"™ (Patent Pending) has five pieces, not just four! They also seem to have solved the problem of homogeneous brazing/welding. But the assembly manual is a real nightmare!

Now this man is in desperate need of a Widgetator of any kind!

4 all u kats out there - that's a great purrspective on this problem

I just received an e-mail (not sure if the sender would care, but I will keep him anonymous for now) with a good question on the above, so I thought I would share my answer:

"Good Morning: Mr. STL Engineer

Great art work ala M. C. Escher, Jr.

Special art program or what? Very impressive..."

Actually, I googled and found these on the web. Unlike the works of MC Escher, who worked exclusively with 2D art, making optical illusions as our brains attempt to convert the images to 3D or some other reality, these appear to be actual photographs. However the objects are probably designed in 3D to mimic the appearance of the Escher sketches (Didn't they sell that as a toy, the Escher-sketch? ) but only from a certain angle, from which they are photographed. From any other angle their true form would be a give-away, but from this particular angle it looks, well, impossible!

Here is a good example (URL below) of what I mean, first from the "Escher Angle" in a distance shot, then from two other angles. Then the last photo is of the illusion again, but closer in. Notice that the lightpole behind the object is in exactly the same place (relative angle) in the last photo as in the first one:

http://www.moillusions.com/2007/04/perth-impossible-triangle-optical.html

I once had an engineering drawing on paper of an object of similar geometry to this, complete with detailed notes and title block of a major aerospace company!

If you have this or anything like it as a engineering drawing on CAD or as a PDF or other image (JPEG, Bitmap, etc.) please send it to me by sending me a message via CR4 mail, with the image attached, and I will send you my e-mail address if necessary to get a better quality image.

Thanks!

There was only one pic on that site that displayed for me...enough to see that this uses the same concept as that of the UK's Channel 4 logo, which creates a "4" from electricity pylons, blocks of flats, shadows on grass, etc, etc.

Your tech drawing uses the same principle as the 5-legged elephant (I'll try to find a copy)

"Your tech drawing uses the same principle as the 5-legged elephant (I'll try to find a copy)"

I think I saw one of these years ago. It was after a night of pub crawling and this 5-legged elephant came right up to me and asked if I had seen his friend Harvey, the six-foot tall rabbit.

ROFL

The only type extinguisher that I am aware of for metal fires is graphite (type M).

It works by "stealing" the heat away from the fire.

Maybe the answer will come from a gentle massaging of the term 'welding'? I think I found a product which may be similar to the alloy in question but I want to figure out how it works first before blurting.

I think we must ask Timothy if the melting point of his welded/brazed components is higher than that of his soldered components.

Yes I believe it can be possible to find a single alloy that could be used to weld with and solder or braze. I have seen with brazing that the base metal can be heated to puddle so that the brazing rod can be used as a filler.

Do not think you would obtain the weld strength you would using a welding filler.

soldering is a surface bond were the solder adheres the two base materials holding them together. welding is a penetration bond melting the two base materials together with the filler mixing in to the base materials.

I have no idea what the widgetator is used for,(perhaps a tool on the moon, or Mars?) but it could be made of ice.The melting point and freezing point of ice is exactly the same( all other factors being equal).To braze, simply apply 0 degree Centigrade water to the joint,which has been chilled below 0 degrees C and allow the base ice to remove the latent heat(334 Kj/kg -1) to convert the water to ice.In the process, the water will bond to the ice base. To weld, simply apply the proper amount of heat to the joint before adding the water.When the heat is removed,the ice will freeze and result in a welded joint. The same principle can be applied to almost any substance as well as ice.

Simple question, simple answer.

Call your next case.

HTRN

If the material has to be metal, use Mercury, applying the same priciples of Latent Heat.

A Phosphor/Bronze material with a high Tin content (7-9%) could be used to either braze Cast Iron to same, or Carbon Steel, as well as weld Brass/Bronze together in Gas Shielded environment. That would only work under the premise that

"two components are soldered or brazed and two components are welded"

actually implies 4 separate components. If not, perhaps something in the line of a 65/35 W/Ag material might work.

One other possibility might be different fluxes.

Solder paste is floated in one type, Braising rods are coated in another, and welding rods are shielded by another.

If I am not mistaken the solder and braising fluxes lower the melting points of the filler metal.

I've used all three but can claim only proficient mastery of soldering.

just another option/opinion.

Question:"Can he find a single alloy to solder and weld his assembly?"

Answer:Yes.

I have done this myself with 304 stainless and copper/silver brazing rod. Brazing was done with a standard silver brazing flux and oxy/acetylene torch. The welding was then done with TIG welding. You could do it the other way around too. The alloy created from welding has a higher melting point than the base metal and this keeps the weld joint from melting at the subsequent braze temps and the other order you have the localized heating from TIG keeping the lower temp braze joint from melting.

I once did it joining copper and brass components using a 96/4 tin/silver solder, I just just screwing around and the joint wasn't too great in places but good enough to indicate that with some practice, better heat control(heat sinking and gas purging), and a cleaner joint it could be done.

"The alloy created from welding has a higher melting point than the base metal"

Wow! If that was truly verified by micro-structural analysis and, more practically, attempted de-brazing (below weld temperatures) of the "welded" joint, than I think we have a winner!

I just wonder what the "higher melting point" alloy is composed of that has a higher melting (liquidus?) point than 304 stainless (1400°C). Is it Copper/Iron or Silver/Iron alloy?

In the same vien:

"Solders have a liquidus below the base metal, while welding alloys fuse with the base metal"

One (of very few) thing i do remember from welding class is that when you use DC, the Positively charged electrode is hotter (useful in controlling penetration). If the same alloy is used for both the components being joined and the filler material (welding rod), with a wide liquidus/solidus range (i.e. Cu30/Zn30/Ag40 - approx. 100deg F). Could you control the heat enough by changing the positive electrode from the components to the rod to melt one and not the other? So when the rod is positive it is essentially brazing (by definition) and when the components are positive they weld without consuming the rod.

"The alloy created from welding has a higher melting point than the base metal"

um, I don't think so...I meant to write filler metal, not base.

OK, I'll buy that, sounds reasonable, but the statement in the first paragraph in#27 still stands. I'm from Missouri, so you gotta "Show Me!", and prove it. I still would like to know what alloy you are forming when you weld with your filler metal that is higher temperature capable than the original filler metal that you use for brazing!

"I'm from Missouri, so you gotta "Show Me!", and prove it. I still would like to know what alloy you are forming when you weld with your filler metal that is higher temperature capable than the original filler metal that you use for brazing!"

Well, can't show you, "Missouri". Perhaps if am allowed to retract my statement using such high tech terms as alloy and base metal you, and others, will more readily accept the fact that it is not a problem to use a single type of brazing rod as a weld filler and a braze filler on an assembly that consists of several parts of the same metal. Done it, not real hard. But maybe you'd rather nit-pick than get the gist...

Have you demonstrated that your "welds" have similar strength to the metal you are joining. If so, you may have a weld.

More likely (and this is not at all unusual) is that you have a high-temperature braze that you are calling a weld. The problem is that, if you apply the brazing rod to the part before you make the join it will cover the entire joint surface, and the joint will be in the braze alloy. If you apply it after a joint is made, you have a welded region with brazed sections around it.
The possible exception is if the substrate materials to be joined are highly permeable to the braze alloy; in this case the joint is initially a braze, but the alloy can diffuse away into the substrates which can then eventually weld; usually, but not always, incorporation of braze material results in the substrate becoming embrittled.

Fyz

__________________________

I'm no expert - (nothing new there)

I don't know that a weld joint is defined as having a similar strength in the weld metal as in the base metal. Of course a good weld joint would have that, unless for some reason a weakness in the joint was beneficial.

As I understand it, a weld is when two pieces are joined together by melting the base metals of the parts at the joint. Brazing and soldering are nominally the same excepting the melting points of the braze and solder metals, and as someone may point out there are some molecular process differences.

The quality and composition of the weld joint I created is quite open to debate and I make no statements concerning it. I do stand by the statement that is a weld joint. The base metal of the two parts were melted and while molten a filler metal was melted into said joint and it is a weld joint. The metal mixture of the two bases and filler would be called "weld metal". Surely it is a very brittle joint due two the dissimilarities of the S.S. and copper/silver, but a weld joint nonetheless.

I have done some crap "braze" joints with brass filler joining S.S. to brass and having the base brass melt...this may be a so called "high temperature" braze joint and only one base metal melted...or maybe there is a term for such a hybrid joint...I dunno

I obviously stated slightly the wrong case. My true question is "How you know you have a weld?".

Doyou make a joint in the absence of the 'solder alloy', and then apply the solder as the joint cools below the welding temperature? or
Have you performed sections where you can isolate slivers without solder that still remain joined? or
Have you demonstrated you have a weld in some other way that I would understand?

Thanks

Fyz

Fyz,

Think of basic oxy/acetylene torch welding. One uses the flame of the torch to create a small puddle of molten metal at the joint of two parts then you feed a slender rod of metal, your filler, into the puddle thereby melting some of the slender metal into the puddle of base metal. You now have the the metal from three different sources, from each of the two parts and the slender rod, all happily(we hope) melted together. When you remove the heat of the torch from the puddle the metal cools and what remains is called a weld. Now the quality of the weld is dependendt on many factors, some of them having to do with the metals used in making the weld, but having melted the three pieces metal together you have made weld.

Gid

That is not in principle how I have understood a weld - but it may be a matter of extent. It is a weld if the joint is composed of material that is substantially the same as the substrate. If the lower-melt temperature jointing material has a significant effect on the melting point, it definitely becomes a braze. Even "standard" PCB soldering techniques can dissolve significant amounts of the copper (as you will find out if you try to re-work a PCB too often).

However, if the joint is well-mixed, either it not a weld (because it is dominated by the solder material) or the amount of solder material is negligible (so why are we using it?).

I admit that with some substrates and solder mixtures there could be a region in-between, where the solder bulks out the substrate material in the joint, but the properties are still similar enough to the substrate to regard it as a weld. But we really are just playing with language at this point, I think.

Fyz

"But we really are just playing with language at this point, I think."

Oh, gee, we wouldn't want to do that, now would we Fyz?!

Hmmm, what is a "weld"? ....what is an "alloy"? Sounds hauntingly familiar!

ROFL

I thought that TIG was used for welding reactive low-temperature materials like Mg and Al alloys. Is that what you mean, or have I missed some capability of high temperature reduction welding to create a compound alloy with a higher melt temperature than any of the three constituents?

________________

I'm no expert (nothing new there)

I'm almost certain that the alloy created from TIG welding 304 stainless using copper/silver brazing rod does not have a higher melting point than the base metal (304 stainless). However, it does have a higher melting point than the filler metal (unless you use way too much filler) and that is enough to keep the welds from melting when you start brazing.

Surely "filler" disqualifies itself because it is another component to buy? In any case, SFIK the usual filler rod material for 304 stainless would be 308 stainless; could that really have a lower melting point than a copper-silver alloy?

Fyz

________________

I'm no expert (nothing new there)

I'm certainly no metallurgist, but I though copper could be soldered, welded and brazed.

I should learn a lot with this challenge.

______________________________________________

There are 10 kinds of people in this world: those who understand binary and those who don't.

Kinsale:

Soldering and brazing are essentially the same process, at least metallurgically-speaking. Copper can be soldered or brazed if a filler material, like tin-lead or other alloy of lower melting point than the copper is used. In this case, it works much like glue, adhering to the base metals and forming a rigid bond between them, without deforming the parts. The brazing material remains in its original chemical form as does the base metal with no mixing or dissolving of the two.

Welding, on the other hand, requires that either some material of the parts to be joined is sacrificed or a filler metal is used and this sacrificial metal liquefies and becomes one with both parts on solidification. In a really good welded joint it would be difficult to see where one part stops and the other begins. Welding also differs from brazing in that, for the same base metal, the temperature must be higher, high enough to actually melt the surface of the base metal of the parts and form a metallic bond between them and the filler material, making the assembly extremely homogeneous at its joint. Welding is usually stronger than brazing, but strong and light brazed parts can be made by reinforcing the joint with another part.

Bicycle frame construction used to be very typical of this, since thin-wall tubing was difficult to weld and brazing with joint reinforcement was the best process for lightweight frames. Heavier frames (cheaper bikes) were made by welding thick-wall materials. However, modern welding and part fabrication techniques now allow thinwall tubing to have thicker walls on the ends, more suitable for welding.

The heart of the question goes to finding one filler material (alloy?) that will work for both brazing and welding. If the two pairs of parts are all the same material, this is difficult. I proposed a solution for this case using a bi-metal solid mixture, though not a true "alloy".

If the pairs of parts are of different materials (the parts in one pair being compatible for welding) and the two materials have different melting points, then one filler material may be found that melts below the higher welding/melting temperature of one pair (to make a good brazed joint), but very near the lower welding/melting temperature of the other pair (to make a good weld).

I don't remember where nor when, but I was taught somewhere that if the melting point (liquidus) of the alloy was below 800° F, it was soldering, if above 800° F, it was brazing. In both cases the joining alloy melts, while the parts being joined do not.

Most of our brazing is done at much higher temperatures (1900° F +). Photomicrographs of these brazed joints show me that at these temperatures, there is significant penetration of the filler metal into the base metal, which indicates formation of a new alloy in the transition region. I presume and have been told that this new alloy (of braze material and base metal) has a liquidus higher than the braze alloy but lower than the base metal. This means that the parts can, if the filler is thin enough, be brought up to brazing temperature a second time with no support, and not fall apart.

How about using a silver plated cooper wire or Nickle plated wires for the welding rods.

"silver plated cooper wire"

Is this a fancy wire for holding wooden casks (barrels) together?

Main Entry: ¹coo·per Pronunciation: \ˈkü-pər, ˈku̇-\ Function: noun Etymology: Middle English couper, cowper, from Middle Dutch cūper (from cūpe cask) or Middle Low German kūper, from kūpe cask; Middle Dutch cūpe & Middle Low German kūpe, from Latin cupa; akin to Greek kypellon cup — more at hive Date: 14th century : one that makes or repairs wooden casks or tubs

No, We used silver plated copper and nickle plated copper in wiring for aircraft. The wiring has to withstand the high heat of a fire to allow the pilot to find a place to land if need be. Usually it is only 30 to 40 seconds before they wiring burns thru even with Nickle plated copper.

It was just a joke, Dad!

Timothy can use a CO2 laser to do both welds. A CO2 laser will bond the materials together and he won't need any alloy!

Anonymous

Well, I have done some research, on Google and thru my own memory, on the subject of widgets. Surprisinginly, widgets are quite common. You may have one and not know it. CR4 itself probably makes extensive use of them!

Here are the results of my research on what a widget is (in my own words, where they vary form Google):

1. A meta-thing, an item of ambiguous description, with an indeterminate purpose, except to use as an example or illustration of itself.

2. A thing with an unknown name, a doodad.

3. A control device with a purpose unknown (or unspecified) to the speaker.

4. A WIndows gaDGET, a graphic symbol that adds functionality, or retrieves content of a specific nature. (What we might see here on CR4 and not know it's a widget.)

5. According to legend, a buggy whip holder.

6. According to my memory, a hand tool used to taper the long wooden handles of other hand tools. I remember a program on PBS, The Old Yankee Workshop, forerunner of The New Yankee Workshop, where the host of the program used old tools from America's colonial period to make things. Back in those days, people had to make their own tools, or if a handle broke, they had to make their own replacement handle.

Because #5 & #6 are obosolete items, and #1 - #3 are too ambiguous to offer any guidance in solving the challenge, that leaves #4 as the only possibilty based in reality to deterimine what widgetation or widgetization means.
Unreal, isn't it?

Unreal, isn't it?

Exactly correct, as in your #1 definition!

I really think a widgetator is a genetically engineered species of potato.Like sweet 'tator, Irish 'tator, etc.

'Course that is just a farmer's opinion.

Oh, yeah. Like:

commen 'tator - Pretty much your normal, everyday, run-of-the-mill 'tator.

commu 'tator - one of them pinko spuds. Their roots always grow to the left.

dic 'tator - The kind the farmer's wife really, REALLY, REALLY likes!

spec 'tator - When you play Mr. Potato Head, you'll need lots of "specs" cause of all the "eyes".

agi 'tator - Dunno, one of them furrin 'tators from Asia, maybe?

There is more than one or two ways to weld a widgetator...The edges could be soldered initially to hold the parts in position, then resistance welded thru the center, no filler needed, depending on the shape of the piece, and strength required.

Laser welding of the component requiring welding is also an option, requiring no filler.

Perhaps the brazed part is connected to the center of a thin stainless steel diaphragm, and the edges are secured to a housing by laser welding?

Just a few ideas that popped up while I was examining my navel lint.....you know how unreliable those voices can be.....

HTRN

Yes, he can find one material to do both jobs.

Brazing requires the filler to melt at a lower temperature than the base metal and the liquid filler will dissolve some of the surface material, while fusion welding requires the base metal be molten before the filler is added and then the two materials will mix in the liquid state. I would recommend furnace brazing of the two joints first and follow that with automatic GTA welding of the remaining two joints to prevent them from melting in the furnace during brazing. The strength of the welded joints would not be ideal, however it can be done. If Tim is really so cheap, why not just redesign the welded joint to use no filler at all?

Has anyone else read the "official" answer yet this morning? I guess it was just that simple, and although he did not name the exact alloy, TVP45 had the right idea.

Not much of a challenge was it? I guess my interpretation of the question was partially based on the "it can't be that easy" assumption. Of course there are alloys that are compatible with one set of materials for soldering/brazing because the base metal melting point is much higher and so do not fuse with the filler alloy, and are also compatible with a completely different set of materials for welding, because the other base metals weld at a lower temperature and so fuse with the filler alloy.

A more difficult question would have been if all of the parts were of exactly the same material and two of the parts had to be assembled by soldering or brazing while the other two had to be welded, all with the same filler material. In that case, my solution in post #4 could have provided a correct answer.

Apart from being the "obvious" answer as defined by STL*, it's a blatant advertisement. And I can't imagine anyone could have learned anything from this answer.

Fyz

*If there was an emoticon showing a raised hat, I would use it here.

"...it's a blatant advertisement. And I can't imagine anyone could have learned anything from this answer."

Darn you, Fyz! How do you see the forest for all those trees in the way?

I would really like to know who is the author of this "challenge" and whether or not they have a relation to the manufacturers or sellers of the particular products mentioned in the "official" answer.

I know that CR4 is a commercial site, so there may not be any preclusion from advertising in the user agreement, better check on that. I at least hope that Globalspec picked up some bucks and didn't give out free advertising on this one!

There are rules on advertising on CR4 - you can only promote your product in the Commercial forum. You can also tag posts that you believe are commercial rather than informative.

Those of us with blogs are warned not to use the blogs to promote our products/companies/friend's product. A valid mention, or reply to someone looking for help, is ok, for example:

Q: How do I ....?

A: Try using a Wigitator. I've been using one supplied by Wigitators 'R' Us for several years now, and it's never let me down.

I think the following reply is also ok: (but check with the admins!)

A: Try using a Wigitator. I work for Wigitators 'R' Us and if you contact me on info@WRU.com with more details of your problem, I'll sort out a visit.

What about the opposite, criticizing a product, is that fair game? For example:

"Wigitators 'R' Us" sells nothing but cheap Chinese knock-off "Wigitators". They can't even spell Widgetator correctly! I had one for three months and it never would go into high-speed Widgetation, even after I had it permanently widgetized. I believe that they have used that inferior Mongolian brazing/welding alloy on the component joints, having to apply too much filler trying to get a strong enough braze. I am just lucky it didn't fly apart and kill me when I attempted High-speed Widgetation!

No, stick with the one and only original Widgetator™ from our friend Timothy's Real American Widgets, Inc. (RAW). Try their Widgetator website: www.realwidgetators.com. If you order from the website you will get a RAW deal from them, that's for sure! Or, call toll free: 1-800-WIDGETS (1-800-943-4387) and ask for the Widgetator and Accessories Direct Sales department, or just ask to speak to the WADS. They know how to give you a RAW deal, too!

I got a RAW deal recently and I was never happier. I tossed my old Chinese "Wigitator" into the dumpster and sent a memo to the rest of our company to never again buy that brand! Now I can have normal AND high-speed Widgetation! I rarely have to widgetize, but when I do, its nice to know that RAW has got me covered!

Nicely put. I think some of the first part might be OK, if you can prove your case when the importers sue you. But supposing Widgetator is a brand name or not to be found in a dictionary, the importer might get you on that.

Fyz

"if you can prove your case when the importers sue you."

Well, see, there's the rub. A lot of what is written here is opinion and anecdote, especially when it comes to product performance. Can one really be sued for what might be written in an on-line blog?

"But supposing Widgetator is a brand name or not to be found in a dictionary, the importer might get you on that."

Not sure I follow your thinking on that, can you elaborate? I would think that an importer who uses a brand name similar to one already trademarked for an invention, or which does not exist as an ordinary word in the public domain (assuming that is what you meant by "not to be found in a dictionary") would be the one likely to be sued for trademark infringement, or possibly even patent infringement, once the importer's product got the attention of the original inventor.

If you check the challenge question you will see that the author did use the trademark symbol and capitalize "Widgetator", so it is implied to be a trademarked brand name, which we also infer is held by Timothy's company, so that an importer of a different manufacturers product would have not rights to use the name, or even a facsimile of it. US Customs warehouses are full of confiscated products like that, awaiting disposal for trademark violations.