Laser Cutting

Some aluminum alloys cracks in the melted portion of a thermal cut and so after any thermal cutting should guarantee that any potential cracking is removed. A pre-existing cracks on a thermally cut edge can act as a stress riser that could lead to fatigue crack prorogation over the years in aircraft parts.

Laser cutting is not common on aircraft sheet metal as it is aluminium. I work with it a lot. you would think it was stainless as it is not anything like aluminium sheet in general and is as hard as a cats head and more springy than Skippy.

Aluminium is a light reflector and heat reflector, when contacted by heat is a super heat sink, so, even coated or painted, this causes the laser to blow back randomly, and though not super noticeable put beside a sheet of mild steel you quickly see how "not" clean the cut really is.

We us it in heat reflection of radiated heat and it is a bitch to work with, the roll itself takes several people to handle it and not from weight, just stopping it from unwinding like a giant super spring.

Structural parts have end result requirements of specification, not standards of manufacturing of how the end result is achieved, (excluding some environmental requirements)

Thank you for your imput. I believe your problems with aluminum you spoke of are with Co2 Or yag type Lasrs. The new technolgy Fiber Laser for cutting and welding, has solved most of those issues. Fiber can now cut or weld up to I" thk steel, I/2" and some case 5/8th thk aluminum and stainless and at same or better speeds than Yag or Co2. with a nice clean edge. Fiber need much less cooling, hense a very small cooling unit, compared to Yag or Co2 . With Fiber, which has shown to be much longer life, rated minimum 100,00 hours. and much less operating and maintenace costs, repacement parts are a fraction of Co2 or Yag. Fiber has little or no maintenance costs. Operating studies show cost for Co2 $18.00 per hour Fiber $4.00 per hour.

I sell Cy Lasers, and was trying to find out if Fiber cutting is now being used on aircraft structural or sheet metal parts, such as wings skin,and leading edges. I thought with the new Fiber cutting technolgy it may now be an appoved process for aircraft structural parts.

I was told by a company that cut non structural aluminum parts with Co2, that with just a little sanding on thin sheets and a slight skimming by machining on thick parts removes any problem with brittleness, what they call the"P" factor of aluminum. In fact they feel less effect, than when cutting with a turret press.

I know a Skikorski Helcopter engineer, and Phd. wrote a paper on this a few years back, suggesing that at that time with Co2 it did not have any adverse effect at the cutting area, in fact less effect,than where the holes for riveting were drilled or punched. If you want to see Fiber cutting go to www.cy-laser.us Their Fiber machines give a very exceptale cutting edge, it may be solution to your aluminum problem .I think the problem is no one wants to go through the testing, and FAA red tape, to see if this process could be an approved method of cutting.

Thank's again for your reply.

"and FAA red tape"

Amen, and a top reason we use water jet extensively. Of course, since most of our stuff is one-off's we also don't need the high production levels that a laser would help with.

Hooker <-- Dynamic Aviation Grp, Inc.

Here is an interesting article: http://www.optoiq.com/index/lasers-for-manufacturing/display/ils-article-display/322828/articles/industrial-laser-solutions/volume-23/issue-3/features/application-report/laser-cutting-aerospace-aluminum.html

no heat here. http://www.youtube.com/watch?v=2jm4_HikMqk&feature=player_embedded

Laser beam machining in a NADCAP special machining process. Its use is approved on a per part basis by the individual airframe and parts manufacturers. It solely depends on the parts end use and on the company that holds the design rights.