IMPC

DMLS materials from EOS vary from bronze-based alloys to tool steel and stainless steel. Light metals on the basis of titanium and super alloys, for example cobalt-chrome, have already been developed at EOS for use in EOSINT M systems. Such alloys are especially interesting for applications in the medical device industry, as well as in aerospace.
 

EOS MaragingSteel MS1
EOS MaragingSteel MS1 is a maraging steel in fine powder form. Its composition corresponds to US classification 18 Maraging 300, European 1.2709 and German X3NiCoMoTi 18-9-5. This kind of steel is characterized by having very high strength combined with high toughness. It is easily machinable after the building process and can be easily post-hardened up to approx. 55 HRC by a simlpe thermal age-hardening process. This kind of steel is conventionally used for complex tooling as well as for high-performance industrial parts, for example in aerospace applications.

Typical applications:

heavy duty injection moulds and inserts for moulding all standard thermoplastics using standard injection parameters, with achievable tool life of up to millions of parts
die casting moulds for small series of up to several thousand parts in light alloys
direct manufacture of heavily loaded functional metal prototypes.

DirectMetal 20
DirectMetal 20 is a very fine-grained bronze-based, multi-component metal powder. The resulting parts offer good mechanical properties combined with excellent detail resolution and surface quality. The surfaces can be easily post-processed by shot-peening and can be polished with very little effort. The specially developed powder mixture contains different components which expand during the laser-sintering process, partially compensating for the natural solidification shrinkage and thereby enabling a very high part accuracy to be achieved.

This material is ideal for most prototype injection moulding tooling applications (DirectTool) and for many functional metal prototype applications (DirectPart). It offers the highest building speed and thus is particularly suitable for larger tools and parts. It also offers a broad window of usable process parameters, e.g. a wide range of achievable mechanical properties and build speeds. Standard parameters use 20 µm layer thickness for the skin and 60 µm layers for the core, but for faster building the entire part can be built using 40 µm layers for the skin and 80 µm layers for the core. Using standard skin parameters the mechanical properties are fairly uniform in all directions, which is especially beneficial for many DirectPart applications.

Areas built with core parameters have a porous structure, but the combination of skin and core produces a strong total part. Parts built from DirectMetal 20 also have good corrosion resistance.

Typical applications:

injection moulds and inserts for moulding up to tens or even hundreds of thousands of parts in standard thermoplastics using standard injection parameters
direct manufacture of functional metal prototypes.

EOS StainlessSteel 17-4
EOS StainlessSteel 17-4 is a pre-alloyed stainless steel in fine powder form. Its composition corresponds to US classification 17-4 PH and European 1.4542 and fulfils the requirements of AMS 5643 for Mn, Mo, Ni, Si, C, Cr and Cu. This kind of steel is characterized by having very good corrosion resistance and mechanical properties, especially excellent ductility in laser processed state, and is widely used in a variety of engineering applications.

This material is ideal for many part-building applications (DirectPart) such as functional metal prototypes, small series products, individualised products or spare parts. Standard processing parameters use full melting of the entire geometry with 20 µm layer thickness, but it is also possible to use skin and core building style to increase the build speed. Using standard parameters the mechanical properties are fairly uniform in all directions. Laser-sintered parts made from EOS StainlessSteel 17-4 can be welded, machined, micro shot-peened, polished and coated if required. Unexposed powder can be reused without restriction or refreshing.

Typical applications:

engineering applications including functional prototypes, small series products, individualised products or spare parts.
parts requiring high corrosion resistance, sterilisability, etc.
parts requiring particularly high toughness and ductility.

EOS StainlessSteel PH1
EOS StainlessSteel PH1 is a pre-alloyed stainless steel in fine powder form. This kind of steel is characterized by having very good corrosion resistance and excellent mechanical properties, especially in the precipitation hardened state. This type of steel is widely used in variety of medical, aerospace and other engineering applications requiring high hardness, strength and corrosion resistance.

This material is ideal for many part-building applications (DirectPart) such as functional metal prototypes, small series products, individualised products or spare parts. One potential application is injection moulding tools for processing of corrosive plastics. Standard processing parameters use full melting of the entire geometry with 20 µm layer thickness, but it is also possible to use 40µm layer thickness and skin and core building style to increase the build speed. Using standard parameters the mechanical properties are fairly uniform in all directions. Parts made from EOS StainlessSteel PH1 can be machined, spark-eroded, welded, micro shot-peened, polished and coated if required.

Typical applications:

engineering applications including functional prototypes, small series products, individualised products or spare parts.
parts requiring high corrosion resistance, sterilisability, etc.
parts requiring particularly high strength and hardness.

EOS CobaltChrome MP1
EOS CobaltChrome MP1 is a fine powder mixture for laser-sintering on EOSINT M 270 systems, which produces parts in a cobalt-chrome-molybdenum-based superalloy. This class of superalloy is characterized by having excellent mechanical properties (strength, hardness, etc.), corrosion resistance and temperature resistance. Such alloys are commonly used in biomedical applications such as dental and medical implants (note: widely used in Europe but much less so in North America), and also for high-temperature engineering applications such as in aero engines.

The chemistry of EOS CobaltChrome MP1 conforms to the composition UNS R31538 of high carbon CoCrMo alloy. It is nickel-free (< 0.1 % nickel content), sterilisable and suitable for biomedical applications. The laser-sintered parts are characterized by a fine, uniform crystal grain structure. They fully meet the requirements of ISO 5832-4 and ASTM F75 for cast CoCrMo implant alloys, as well as the requirements of ISO 5832-12 and ASTM F1537 for wrought CoCrMo implants alloys except remaining elongation. The remaining elongation can be increased to fulfil even this standard by hot isostatic pressing (HIP).

This material is ideal for many part-building applications (DirectPart) such as functional metal prototypes, small series products, individualised products or spare parts. Standard processing parameters use full melting of the entire geometry with 20 µm layer thickness, but it is also possible to use skin and core building style to increase the build speed. Using standard parameters the mechanical properties are fairly uniform in all directions. Laser-sintered parts made from EOS CobaltChrome MP1 can be welded, machined, micro shot-peened, polished and coated if required. Unexposed powder can be reused without restriction or refreshing.

Typical applications:

prototype or one-off biomedical implants, e.g. spinal, knee, hip bone, toe and dental
parts requiring high mechanical properties in elevated temperatures (500 - 1000 °C) and with good corrosion resistance, e.g. turbines and other parts for engines, cutting parts, etc.
parts having very small features such as thin walls, pins, etc., which require particularly high strength and/or stiffness.

EOS CobaltChrome SP1
EOS CobaltChrome SP1 is a fine powder mixture which produces parts in a cobalt-chrome-molybdenum-based superalloy. In addition to excellent mechanical properties (strength, hardness etc.), corrosion resistance and temperature resistance, it has been especially devel-oped to fulfil the requirements of dental restorations which have to be veneered with dental ceramic material.

Typical applications:

dental restorations (crowns, bridges etc.)

Metal Injection Moulding (MIM) is a process that has developed out of the conjunction between powder metallurgy and plastic injection moulding.

MIM has a wide area of applications which include watch cases, radial rotors, turbocharger rotors, automotive parts, surgical tweezers, gas manifolds, fuel nozzles and many others.

The MIM industry has been driven by reduction in production costs as compared to other methods and MIM has become a mature technique for the fabrication of small and difficult to machine parts with complex shapes. Figure 1 shows competing technologies and Figure 2 identifies the optimal application of MIM.

The MIM cycle

The MIM cycle begins with preparation of a feedstock by mixing together very fine metallic powder with a binder comprising waxes, polymers, lubricants and surfactants as shown in Figure 3. The resulting feedstock is then granulated.

An injection moulding machine is used to heat up the feedstock before injecting it into a mould cavity under pressure. The molten feedstock is allowed to cool, solidify and become what is known as a “green” part.

The binder components are then removed by the process of debinding and the brown moulding becomes a highly porous “brown” part. The brown part is sintered at elevated temperature and shrinks during the process typically to over 95% density.

IMPC has a DMLS powder bed machine in-house, which is used for the production of complex components in stainless steel and superalloys.

EOSINT M 270 builds metal parts using Direct Metal Laser-Sintering (DMLS). The technology fuses metal powder into a solid part by melting it locally using a focussed laser beam. The parts are built up additively layer by layer. Even highly complex geometries are created directly from 3D CAD data, fully automatically, in just a few hours and without any tooling. It is a net-shape process, producing parts with high accuracy and detail resolution, good surface quality and excellent mechanical properties.

A wide variety of materials can be processed by the EOSINT M 270, ranging from light alloys via steels to super-alloys and composites. EOS has developed novel alloys especially for the DMLS process, and has also optimized and qualified standard industrial materials such as stainless steels for this machine. Further materials are continually being developed and qualified.

New Perspectives in Manufacturing with DirectPart
EOSINT M 270 is widely used to produce positive parts directly from CAD data. This application is called DirectPart. The components can be prototypes, series production parts or even spare parts. Whether the requirement is to deliver a functional metal prototype within one day, or to economically manufacture hundreds of individualized implants in bio-compatible alloy each week, EOSINT M 270 offers the solution.
 

Rapid and High-Performance Tooling with DirectTool
DMLS is well known as a leading technology for toolmaking, an application known as DirectTool. With its high accuracy and surface quality, EOSINT M 270 is an ideal platform for this application. The direct process eliminates tool-path generation and multiple machining processes such as EDM. Tool inserts are built overnight or even in just a few hours. Also the freedom of design can be used to optimize tool performance, for example by integrating conformal cooling channels into the tool. Increasingly, both strategies are combined to create improved performance in shorter time. DirectTool is best known for plastic injection moulding. However, the technology is also used for other tooling types including blow moulding, extrusion, die casting, sheet metal forming etc.

For more info visit the EOS website.

IMPC has an Electron Beam Melting powder bed machine in-house, which is used for the production of complex components in Titanium alloys.

The Arcam EBM S12 enables Free Form Fabrication (FFF®) of components in solid metal directly from CAD. It offers unique geometrical possibilities for manufacturing in metal.  The Arcam EBM S12 is based on Arcam’s CAD to Metal® technology. The fundamental idea behind the CAD to Metal® technology is to build up metal parts in layers of metal powder, each of which is melted by an electron beam to exactly the geometry defi ned by the computer model.  The Electron Beam Melting (EBM) process is efficient and provides access to high power to fully melt the metal powder.  The parts are built up in a vacuum chamber. Vacuum is a necessity so that the electrons have a clear path to the metal. Vacuum also provides a clean environment, resulting in excellent material characteristics.

Furthermore, the vacuum provides a good thermal environment, leading to good form stability and controlled thermal balance in the part.  The Arcam EBM S12 enables Direct Manufacturing of functional metal parts for applications where strength and material requirements are strict.  The CAD to Metal® technology produces parts in solid metal. Final machining of parts can be done with any conventional method such as high-speed milling, turning, grinding, EDM etc…  The technology brings short lead times compared with conventional manufacturing methods. It also allows for the development of new design solutions by way of high level of geometric freedom.

More info on the Arcam website.

Yorkshire Forward and the European Regional Development Fund (ERDF) have supported the setting up of a £6.7M research centre for Innovative Metals Processing (the IMPC) at the University of Sheffield. This venture between the Advanced Manufacturing Research Centre with Boeing (AMRC) and IMMPEUS (the Institute for Microstructural and Mechanical Process Engineering: The University of Sheffield) will concentrate amongst other things on the processing of titanium and its alloys by powder metallurgy. The IMPC is industrially focussed and is supported by a consortium of industrial partners including; Boeing, Rolls-Royce, Arcam, Arburg, Egide-UK, Materialise, Morgan Advanced Ceramics and the European Powder Metallurgy Association, amongst others.  

The IMPC builds on the recognised excellence of the AMRC in delivering innovative manufacturing technology solutions to the engineering sector and IMMPETUS’ expertise in metals processing and is focused on advanced net-shape processing - with a particular emphasis on metal injection moulding (MIM) and powder based additive and rapid manufacturing technologies.  The centre boasts a range of the latest equipment including two Arburg All-Rounder MIM systems, a Centorr Vacuum Furnace, powder handling and mixing facilities and ARCAM EB12 and EOS M270 powder bed metal processing systems.  This facility is available for use by companies interested in any aspect of these developments. And funding for the centre’s first four years has been secured through a combination of Knowledge Transfer Partnership grants, Engineering and Physical Science Research Council grants, direct funding by the University of Sheffield and in-kind contributions consisting of capital equipment, software, as well as  from Yorkshire Forward and ERDF set-up and support.  After this initial stage, revenue for the centre will come from tiered membership subscription charges, consultancy, research sponsorship and public sector research finance.   

The centre employs academics from the University of Sheffield, technicians and PhD and MSc level students.  Additionally, IMPC sponsor companies are encouraged to place staff in the Centre to collaborate with academic and technical staff on projects.  

All programmes at the IMPC are developed with the priority of transferring knowledge and opportunities into regional companies.  This will be done via direct contact and technology transfer programmes.  Current centre projects include MIM of titanium for aerospace and biomedical device applications, large and hollow sectioned MIM components, mechanical alloying of ferrous metals and development of low cost processes for Ti scrap reclamation.