1,The development of SLM technology is the pacesetter of high-density metal production
principle
SLM technology completely melts metal powders using high-power laser beams and then layers them to build up metal parts with a density approaching 100%. The point is, the laser energy density must be enough to be above the melting point of the metal, and the powder particles must be fully melted and establish a metallurgical bond between them. SLM devices developed from the German technology presented by the Fraunhofer Institute in 1995 meanwhile even can accomplish co-scanning multi laser. For instance, the Nikon SLM solution NXG XII 600 machine is equipped with 12 1 kW lasers, and is capable of building parts reaching a maximum size of 600 × 600 × 600mm ³.
material system
SLM can handle more than 30 kinds of metal materials such as titanium alloy (Ti6Al4V), nickel-based alloy (Inconel 718), aluminum alloy (AlSi10Mg) and stainless steel (316L). For example, in the case of the fuel nozzle of an aircraft engine, GE consolidates 20 different parts into a single component using SLM and reduces the weight by 25% at a fivefold increase in strength and 15% increase in fuel efficiency. In the medical industry, Johnson&Johnson uses SLM printed porous titanium alloy hip joints, which are porosity of 90% matched with human bones, and postoperative rehabilitation cycles are reduced by half.
Technical advantages
Design freedom: can create internal flow passages with complex geometry which are not possible by conventional manufacturing processes (eg cooling channels in a gas turbine blade)
Material yield rate: The powder recycling rate is over 95%, which can save a large amount of material, and is 70% cheaper than the waste of CNC structure: the thickness of the structure is high density: up to 99.5% used in100%real.Lhumid air.
Performance stability：The fatigue strength of the printed titanium alloy parts is 92% of the forging level
Quick Turn: shorten the period from design to sample to 1/5 of traditional mold manufacturing period
2, Compatibility Expert for Multi Material Systems:DMLS Technology
Essence of craftsmanship
DMLS and SLM are easily confused, and as a matter of fact, DMLS is using the principle of a partial melting to make metal powder particles laser melted together in solid, and the product is what we define as porous part. It is more appropriate for multi-component alloy materials such as cobalt chromium alloy (CoCrMo) and copper alloy (CuNi2SiCr). Shewn by comparing the surface roughness Ra of the printed oral implants of the present invention with that of the Implant of the Prior Art, the surface roughness Ra of the printed oral implants is ≦ 0.8 μ m, which can satisfy the clinical implant requirement directly.
Typical applications
Aerospace: Material and technology wise, Airbus apply DMLS printed titanium alloy brackets to achieve a 100% increase in stiffness and a 29% decrease in weight.
Mold manufacturing: DMLS printed conformal cooling molds speed up the injection cycle by 40% and productivity deformation rate by 65%
Gems and jewellery:18K gold and Pt gradient printing application through DMLS to satisfy personalisation requirements of high-end customers
Technological breakthrough
The DMLS machine presented by EOS company could perform 5 axial linkage printing, which could print any structure as long as the structure has no supporting elements. For instance, a one satellite bracket takes the optimized lattice design taking parts from 17 to 1 (through DMLS) and also reducing the weight by 30%.
3, EBM Technology: Extreme Manufacturing in Vacuum with Medical Devices
process characteristics
EBM uses high-energy electron beams to melt metal powders in a vacuum, with an energy density that is over 10 times that of SLM lasers. Related Link(s) The machine used to print the parts is Q10plus equipment made by Swedish High Strength Materials Company (previously known as Metal Technology Company)Because the vacuum degree in Arcam is only 4 x 10 ⁻3 Pa, so it is more suitable to print titanium alloy parts, the largest diameter is 350mm, the height is 380mm, this kind of processing active metal is particularly suitable, such as tantalum and zirconium.Other links:
Extreme environmental applications
And in the nuclear power sector for example, Westinghouse Electric uses EBM manufactured tungsten alloy tubes for nuclear fuel cladding because it maintains structural integrity up to 1000℃ or more.
EBM's aerospace: The EBM printed copper alloy thrust chamber tested by NASA exhibits 30% greater heat removal capability than conventional casting
Orthopedic devices: EBM acetabular cups made by Limacorporate, that has a porous surface which facilitates bone cell in-growth and have a loosening rate, for the prosthesis, of 0.3%
Technical advantages
Control of residual stress: oxidation resistance in vacuum, deformation rate is lower than 0.1% for warp part
Print speed: The speed of the electron beam scanning can reach 10m/s, which is 5 times faster than the SLM laser.
Material adaptability: Is suitable for processing high melting point refractory metals with a melting point over 3000 ℃ (such as niobium, molybdenum)
4,Technology selection matrix:Decision model from prototype to mass production
Application scenario decision tree
Heavy shape requirement: prefer SLM (like engine blades of aircraft)
Multi material system: with use of DMLS (as oral implants)
Highly Environmental applications: Go with EBM (nuclear power components)
Cost-sensitive large scale production: Think of SLM+machining -low value piece part (e.g., automotive transmission valve body)