my name's luke carter, i'm a phd student here.i'm researching the effects of selective laser melting fabrication on nickel superalloysfor use in high temperature aerospace components effectively. well the piece we're making todayis just a demonstration piece, a small keyring with the university logo on and one of thereasons for doing that is because most of our work is very heavily tied with industryand we can't show a lot of the components that we make. but effectively it was a cadmodel that i drew up and we take that model and virtually slice it into a whole sequenceof two dimensional shapes, then the laser selectively melts each one of those slicesin turn and bonds it to the previous layer. after one layer has been selectively meltedthe next layer of powder is spread across
by a recoater blade, including a small dropin the build platform and this happens over and over again, so your final part is effectivelyburied in the metal powder and we have to dig it out at the end of the day.traditionally with machining you might think about starting with a large lump of materialand then cutting it away until you have the shape that you want, whereas with additivemanufacturing methods you start with, in this case, a metal powder and then you build upthe three dimensional shape directly as you want it so it's a net shaping process, you'reproducing the overall net shape directly from the cad file, from the computer file. thetechnique might be useful for production, especially when thinking about low batch numbers,so traditional methods, say investment casting,
can be quite cost effective if you're makinghundreds of thousands of things every year but if you start to make maybe only a coupleof hundred a year you might want to think about going to this method which doesn't requirethose expensive set-up costs or custom made tooling for each piece. each piece could beindividual or bespoke, depending on the application. in terms of what we do here, which may bea little bit different to rapid prototyping which is sort of fairly well known and generallyproduces pieces in plastics, we're producing metal components here and the aim is for thoseto be fully dense and functional components. so rather than thinking about this being arapid prototyping technique, it's more of a rapid manufacturing technique.our current projects involve nickel superalloys,
so for aerospace engines typically, titaniumalloys and aluminium alloys but there are plans to have more exotic materials in there.here in the school of metallurgy and material we're trying to focus on the effect of theselective laser melting process on the material itself, with the aim being to produce a componentat the end which has the same mechanical properties as a conventionally cast material or a machinedmaterial, but obviously it's being formed in a very different way so we need to lookat each material in detail and look at exactly
metal powder for 3d printing,how the laser process is affecting the microstructure, which ultimately affects the material properties. and here's the finished product. the nextstep would be to edm wire cut this from the base plate and it might go on for further
heat treatment or finishing if it was a functioningcomponent.
