|
|
Hello everyone,Firstly I need to let you all know that I know next to nothing about welding. I am a aerospace engineer and have a very mathematical background I was wondering if any of you guys would know how to achieve the following...Make a truss like structure from very thin (0.1mm) Ti wire. I have been reading a lot about Diffusion Bonding of Titanium, but am having a little difficulty in finding out exactly how to do it. The problem that I can see with normal welding is that the truss components are going to be 1-2 mm apart. Therefore space is a limitation. Sorry if this all sounds like junk, I am a numbers man!!Hope you guys have a few ideasThanks for readingRob
Reply:Have you considered a furnace/vacuum brazing application?
Reply:Hi, Thanks for your quick reply. I have now!!The only issue I see with brazing is if I would be able to manufacture something with millimetric dimensions. If I explain my end application perhaps it would make life easier. If you can imagine cutting short (1cm) lengths of Ti wire and letting them fall onto a surface. A little bit like having your hair cut and having the hair fall onto itself in a random fashion. Then after bonding you would have a very light weight, and very low density structure. I know it sounds wierd, but I assure you there is logic behind it!!Rob
Reply:I'd think a brazing application for a random matrix like the one you're describing would be far more feasible to carry out than welding. Welding 1mm sheet is no easy task in itself, but to fuse 1mm Ti wire by welding is extremely difficult to begin with. Factor in the random pattern you describe in any real quantity and it may become either impossible, or incredibly time/cost prohibitive. You may want to post this on eng-tips.com. A lot of guys over there privy to modern welding and bonding techniques on an Aerospace level, and really up to snuff on the various metallurgical and practical ramifications of it all.
Reply:Thats brilliant, Thank you very much Supe, I really appreciate your help. I will let you know how I get on for future requests!!Once again, Thanks
Reply:Hi,A couple of methods could be used for this one. A fibres covered in brazing slurry would definitely be the easiest, but the strength of the braze would be significantly lower than a Ti welded joint. Another way would be to scatter a thin layer of your fibres (assuming that I am understanding your application correctly) and scan a laser (pumped diode would be best - lower heat density) over it. It would result in a slightly denser final material than the slurry method though.. Diffusion bonding is something very different and is used on things like fan blades. I can't see how this could be used on your application if a strong light final structure is required - it would just be too fiddly. Diffusion bonding is where patterns are sreened onto to sheet material where the bond is not required. The sheets are placed together, sealed aound the edges and a vaccuum applied to the removed all air and ensure complete contact between the sheets. The whole thing is then baked under pressure to get the bond between the unmarked area of the sheets. Whilst hot, the inside of the structure finally has inert gas blow into it to inflate it. It is a good way to get reinforcement into a structure, but keep the weight low. The problem is I don't think it would work for the dimensions that you are quoting.Throughout all of this, cleaning is critical as is shielding. Blueing of the titanium, due to oxide formation, is not usually allowed in aerospace applications so use that argon. You may need to etch prior to welding also to remove the oxide depending upon the final requirement of your parts. Ask the Electron Beam guys what they do to clean - it will be the best clean prior to welding that you will find in aerospace.Good luck!!Poe |
|
发表于 2021-9-1 00:48:39