3D printing-what are the metal materials for it?

What are the metallic materials for 3D printing?

According to the type of materials, 3D printing metal materials can be divided into iron based alloy, titanium and titanium based alloy, nickel based alloy, cobalt chromium alloy, aluminum alloy, copper alloy and precious metal, etc.  

Titanium and titanium alloy with its remarkable high specific strength, good heat resistance, corrosion resistance, good biocompatibility and other characteristics, become the ideal materials in medical equipment, chemical equipment, aerospace and sports equipment and other fields. However, titanium alloy is a typical difficult-to-machined material, with high stress, high temperature and severe tool wear during machining, which limits the wide application of titanium alloy. 3D printing technology is particularly suitable for the manufacture of titanium and titanium alloys. First, 3D printing is in a protective atmosphere, titanium is not easy to react with oxygen, nitrogen and other elements, and the rapid heating and cooling of local micro-areas also limits the volatilization of alloy elements. Second, the complex shape can be made without cutting, and the material utilization rate based on powder or silk is high, which will not cause the waste of raw materials and greatly reduce the manufacturing cost. Currently, the types of 3D printed titanium and titanium alloys are pure Ti, Ti6A14V(TC4) and Ti6A17Nb, which can be widely used in aerospace parts and artificial implants (such as bones, teeth, etc.).

Fe-base alloy is a kind of alloy which has been studied earlier and more deeply among 3D printing metal materials. The more commonly used fe-base alloy are tool steel, 316L stainless steel, M2 high speed steel, H13 die steel and 15-5pH martensitic aging steel.  Iron base alloy has low cost, high hardness, good toughness, and good machinability, especially suitable for mold manufacturing.  3D printing of conformal channel mould is a major application of iron based alloy. It is difficult to process special-shaped channel in traditional process. However, 3D printing can control the layout of cooling channel and the geometric shape of the cavity, which can improve the uniformity of temperature field, effectively reduce product defects and improve the life of the mould.

Nickel-based alloy is one of the fastest developing and most widely used superalloys. It has high strength and certain oxidation and corrosion resistance at 650 ~ 1000°C, and is widely used in aerospace, petrochemical, shipbuilding, energy and other fields.  For example, nickel-based superalloys can be used in turbine blades and turbine discs in aeroengines.  Commonly used 3D printed nickel base alloy brands are Inconel 625, Inconel718 and Inconel 939, etc.  Cobalt-based alloys can also be used as superalloys, but their development is limited due to lack of resources.  Cobalt-based alloys are currently used as medical materials for dental implants and orthopedic implants because they have better biocompatibility than titanium alloys.  At present, commonly used 3D printing cobalt alloy brands include Co 212, Co 452, Co 502 and CoCr28Mo6.  

Aluminum alloy is an ideal lightweight material with low density, good corrosion resistance, high fatigue resistance, and high specific strength and specific stiffness.  Aluminum alloy used in 3D printing is cast aluminum alloy, commonly used brands are AlSi10Mg, AlSi7Mg, AlSi9Cu3, etc.

Other metal materials such as copper alloy, magnesium alloy, precious metal and other metal materials are not as good as those introduced above, but they also have their corresponding application prospects.