Copper and copper alloys are a class of key materials with important applications. Due to its excellent thermal conductivity, electrical conductivity, extension and corrosion resistance, copper is a necessary material for some applications in aerospace and weapon equipment. In the field of additive manufacturing, the application of copper materials is relatively late, but in recent years, it shows a rapid development trend, especially in the field of national defense and military industry, significant progress has been made continuously, which has promoted the development of additive manufacturing. In the last two years, the growth in demand for copper alloys has been clearly felt in the additive manufacturing industry, and new users have started to develop applications for the manufacture of copper alloys, materials also from the early easy to shape the casting tin bronze to pure copper and all kinds of high-strength and high-conductivity copper. The global additive manufacturing market will grow at a compound annual growth rate of 51% in 2019 and 2027, according to a report by the 2027. Although there are still many process and material problems in the current copper alloy printing, it can be predicted that copper will occupy a place in the metal additive manufacturing.

At present, many foreign well-known additive manufacturers have incorporated copper materials into their product catalogues. Typically, EOS released a data manual for pure copper and CuCrZr in 2020, and 2021 rolled out a dual-material version of AMCM (Additive Manufacturing Customized Machine, a EOS subsidiary) . SLM Solutions launched CuSn10, CuCrZr product data, in 2019, the company introduced the strength and conductivity of CUNI2SICR products, can be used in the mold and electrical field, as a additive manufacturing of copper alloy products in a heavy product. Material Makers TLS Technik, M4P, Sandvik, Makin and others have announced their own additive manufacturing of copper alloys. At present, copper and copper alloy materials used in additive manufacturing are concentrated in pure Cu, CuSn10, CuCrZr and CUNI2SICR. Although CuNiSn, CUCR, CuCrNb, Cualfeni and other additive materials are also studied and applied, their application is not as good as the first four kinds of additive products. Youyan powder new Material Co. , Ltd. (“Youyan powder material”, stock code 688456) is the largest supplier of copper powder in China, selling more than 30,000 tons of copper and copper alloy powder annually, beijing Kangpuxiwei, a subsidiary company of the company, has earlier carried out research and application of copper and copper alloy powder for additive manufacturing in China, and has now formed a more complete series of special copper and copper alloy powder products for additive manufacturing, including pure Cu, CuSn10, CuCrZr, CUNI2SICR, Cualfeni, and so on, in aerospace, mold, electrical and other fields have made important applications.

1. Compared with copper alloy, pure Cu has the advantage of conductivity and thermal conductivity, because all kinds of copper alloy will lose conductivity and thermal conductivity after adding elements into copper. Pure copper is difficult to print because of its low absorption at the wavelength of 1064nm, which is called Red Light Wavelength. The current solution is to use short wavelength lasers, such as TRUMPF’s 515nm Green Laser, and to boost power, such as EOS’s AMCM, which uses a 1Kw laser for pure copper printing. No matter what type of equipment is used for printing, to obtain high density or high conductivity pure copper parts, it is necessary to keep high purity of the raw material powder and at the same time to obtain densified powder characteristics, such as reasonable particle size distribution, good fluidity, loose load density and other characteristics. As far as the preparation of pure copper powder is concerned, the goal is to maintain high purity and sphericity of the material. 2. CUSN10CUSN10 as a cast tin bronze is easy to shape, many models or crafts related to copper material print CuSn10 material. CuSn10 Alloy has high strength, good wear resistance and corrosion resistance. It can be used to make wear-resistant parts such as blades and gears, but its thermal conductivity is not high. CUSN10 is one of the conventional products in the manufacture of copper alloy materials. CUCRZR rocket engine is a typical application of copper alloy. The material requirements of engine lining and related components are very high. On the one hand, because of the extremely high combustion temperature (more than 3000 °c) , on the other hand, high temperature, high pressure and high speed gas have very strong erosion to the material. CUCR alloy is a typical precipitation-strengthened copper alloy, and the addition of Zr element can promote the precipitation of CR phase and improve the distribution of precipitated phase, therefore, CuCrZr alloy has excellent mechanical properties and can be used in the manufacture of rocket engine parts. In recent years, more research and development work has been carried out on the additive manufacturing of rocket engine thrust chamber parts in China. CUCRZR is currently an alternative material. It is worth mentioning that the copper alloy used in rocket engine parts is still in the process of being renewed, CuZr, CUCR, CuAgZr, CUCRNB and other materials have been applied in the research, especially the GRcop-42(Cu-4Cr-2Nb at%) which is being verified by NASA, it is hoped that rocket engine combustor materials will be upgraded to a new level. CUNI2SICRSLM Solutions launched in 2019 the CUNI2SICR copper alloy, a heat treatable hardening alloy with high strength and a balanced combination of electrical conductivity and thermal conductivity that includes nickel and silicon, with high corrosion resistance and wear resistance. CUNI2SICR itself is not a new ingredient, it corresponds to C18000 alloy. SLM SOLUTIONS IS THE FIRST COMPANY TO USE IT in additive manufacturing and has carried out material identification and parameter verification, the addition of an important member to the copper alloy family for additive manufacturing. The strength of CUNI2SICR after heat treatment is obviously higher than that of CuCrZr and other materials, and the thermal conductivity and electrical conductivity can be maintained at the same time. 

Source: Caitong