Material with High Scratch Resistance

How about Stainless Steel or perhaps Titanium. What about a spray-on barrier to coat the surface.

Much more information is needed, what's the application in detail? (I am assuming you are trying to sheath a plastic part to increase its mechanical resistance).

I use that material for additional bed for CNC milling machine. In application, I stick some plastic material (usually ABS resin) to that additional bed by using plastic glue, before machining process. Thats why I'm also need highly adhesiveness to plastic.

I've tried stainless steel, but it doesn't has good adhesiveness to plastic material.

Thank You.

Did you try granite? it is also highly brittle.

So far I have tried with stainless steel, but it has bad adhesiveness to plastic.

Maybe I'll try with granite.

Thank You.

"I've tried stainless steel, but it doesn't has good adhesiveness to plastic material." You should be able to bond Stainless steel effectively after proper surface preparation. Stainless remains stainless due to it ability to protect itself by reacting with atmospheric oxygen. To obtain good adhesion the oxide coat need to be removed before bonding. Stainless steel may be cleaned with the following solution; Concentrated hydrochloric acid...............47% 30% hydrogen peroxide............................ 2% Formalin solution..........................................9% Water...........................................................42% The stainless steel is immersed in this solution for 10 minutes at 650C.

I have to ask how the solution temperature can get to 650C, or is the stainless steel supposed to get to 650C. Either way the solution can't ever get to 650C unless under quit a bit of pressure? Just confused on this technique.

Your are correct! The temperature should read as 150 deg C. The typographical error is deeply regretted. For an even better process for surface preparation of stainless steel refer to http://www.euro-inox.org/pdf/map/Passivating_Pickling_EN.pdf.

The material you need for your machine bed structure will likely be something that can be fabricated into a large and dimensionally stable mass with considerable mechanical stiffness and an ability to resist surface damage from impacts or abrasion attendant to normal use.

Three proven approaches are iron or possibly aluminum casting, steel or aluminum weldment or otherwise mechanically fastened structure and casting of a specialized concrete composition.

It appears that having explored metals and concluded that the challenge there is surface preparation to insure good adhesive bonding you are looking in other directions.

A hard flat material is usually a poor choice for adhesive bonding. That is unless it has some surface configuration with the right size of surface porosity for the adhesive to lock into mechanically. A dense reinforced portland cement could be cast and critical surfaces ground to required flatness. There are numerous other possible cement compositions.

Some commercial applications of concrete and other composition machinery bases exist. A bit of searching will likely turn up companies offering this technology especially where dampening properties are important.

Some 30 years ago I worked as an engineer for a small US company that had developed the first commercially successful digital electronic tire balancer (Nortron). An early product had a base structure made out of a "polymer concrete" chosen for its ability to offer some dampening of vibrations that affected the machine accuracy and good structural integrity. I was not privy to the exact formula for this stuff. The company founder held that information pretty close. But the resultant product worked well and it wasn't until the largest customer insisted on cost reductions that led to the base part being replaced with one made of structural steel. Combined with a second generation of computational programming in the machine control the accuracy was preserved. But that's getting a bit off topic.

If you choose this approach for CNC machining equipment pay attention to differences in thermal expansion of various parts of the system lest they degrade the level of accuracy excessively.

Should you choose to stay with a metal structure you may want to consider a thermal sprayed ceramic coating. It can be applied to a metal surface properly grit blasted to allow mechanical adhesion and then ground flat to your specs by conventional grinding processes. The surface can be applied in a way that allows a grain structure with considerable porosity for absorbance of liquids including low viscosity adhesives. This structure also has the ability to move with thermal expansion and contraction of underlying metal substrates without cracking.

Another approach involves using a thermal sprayed hard metal coating with sufficient roughness that a subsequent operation to machine a flat geometry leaves a uniform pattern of small depressions in the surface. This sounds to me to be less practical especially for large areas because of the difficulty maintaining a uniform coating thickness. Also note that high grade thermal coating can be an expensive secondary process and not a readily available technology in many parts of the world.

A simple form of thermal spraying known as flame spraying uses special acetylene torches to spray metal coatings. This is a common machine repair method when worn down bearing journals need to be returned to original size.

Ed Weldon

we used a material in millwork for bulletproofing. the material is about a half inch thick, solid flat, scratch resistant and will "stick well with others" not sure of the manufacture, but it is EXspensive. probably cheaper just to oxidize the stainless.

Try glass...... just select the right type of glue for glass and your plastic

I have used high temp teflon tape for this application.

Not sure what you mean by "block" material

An epoxy coating. A product named Plascite comes to mind.

If you are painting a car or airplane I have used a Canadian plastic paint product called Endura that is suitable.

Not sure what the polyurethane coating product name is but the following comments on scratch resistant coatings.

Scientists have recently developed a polyurethane coating that heals its own scratches when exposed to sunlight, offering the promise of scratch-free cars and other products. The self-healing coating uses chitosan incorporated into traditional polymer materials, such as those used in coatings on cars to protect paint. When a scratch damages the chemical structure, the chitosan responds to ultraviolet light by forming chemical chains that begin bonding with other materials in the substance, eventually smoothing the scratch. The process can take less than an hour.

Marek W. Urban, a scientist working on this project said that the polymer can only repair itself in the same spot once, and would not work after repeated scratches.

Happy New Year Kala,

You need a system to protect something against something else. Please, take a minute or two and describe more in details what you need. "Flatness" is mat finish or you need horizontally, perfectly even material or finish. Elabote and you get some answer, Gil.