The million dollar question right...is it really worth prototyping the exotic metals using DMLS rather than machining them. I guess it is really going to depend on your time frame and geometry. The thing about DMLS is, its super fast, on top of that it can create really complex geometries. Would it be worth a one off CNC of a titanium or aluminum part if you have to create work-holders and buy a lot of material to do just one part, probably not. Let me talk a little about each of the exotic materials.
Since DMLS is an additive technology, it drastically reduces material waste in comparison with traditional processes. Investment casting of titanium is difficult and often has a high scrap rate. Currently, many titanium aerospace components are machined from solid stock, often cutting away 90% or more of the original material. This becomes a time consuming, costly operation that is completely eliminated with titanium DMLS, not to mention much lower labor costs.
Some of the characteristics that make titanium ideal for aerospace applications also make it difficult to machine. Its hardness and low heat conductivity reduce tool speeds and life, require a great deal of liquid cooling during machining, and limit the productivity of certain shapes, such as thin walls. Laser-sintered titanium retains the beneficial properties of the metal and involves no tool-wear or coolant costs. In addition, nearly any geometry, including thin walls, can be created with laser-sintering. - Nextbigfuture.com
- Direct manufacture of functional prototypes, small series products, individualized products-
- Spare parts requiring good corrosion resitance properties
- Parts requiring a combination of high mechanical properties and low specific weight
- Structural and engine components for aerospace and motor racing applications, etc.
EOS Aluminium AlSi10Mg is a master alloy aluminium- powder. AlSi10Mg is a typical casting alloy with good casting properties and is used for cast parts with thin walls and complex geometry. The alloy combination silicon/magnesium results in a significant increase in the strength and hardness. It also features good dynamic properties and is therefore used for parts subject to high loads.Standard building parameters completely melt the powder in the entire part.
Parts made of EOS Aluminium AlSi10Mg can be machined, wire eroded and electrical discharge machined,welded, micro-blasted, polished and coated. Unexposed powder can be re-used.
- Direct manufacture of functional prototypes, small production runs, user-specific products or spare parts
- Parts that require a combination of good thermal properties with low weight
Machining Inconel 718 is tough and nobody likes to do it. The DMLS process allows you to produce Inconel parts quick, while being affordable.
This material is ideal for many high temperature applications such as gas turbine parts, instrumentation parts, power and process industry parts etc. Material also possesses excellent cryogenic properties and potential for cryogenic applications.
Standard processing parameters use full melting of the entire geometry, typically with 20 µm layer thickness. Parts built from EOS NickelAlloy IN718 can be easily post-hardened to 40-47 HRC (370-450HB) by precipitation-hardening heat treatments. In both as-built and age hardened states the parts can be machined, spark-eroded, welded, micro shot-peened, polished and coated if required. Unexposed powder can be reused.
- Aero and land based turbine engine parts
- Rocket and space application components
- Chemical and process industry parts
- Oil well, petroleum and natural gas industry parts