Pure copper and copper alloys are widely used in the fields of power, heat dissipation, piping, decoration, etc. due to their excellent electrical conductivity, thermal conductivity, corrosion resistance and toughness. Some copper alloy materials have good electrical conductivity, thermal conductivity and comparative High strength, widely used in the manufacture of aerospace engine combustion chamber components. However, with the increasing demand for complex structural parts on the application side, traditional processing techniques have gradually failed to meet the demand.
Selective laser melting metal 3D printing technology has the advantages of forming complex structural parts, high material utilization, and no need for molds. This technology has great application potential in the preparation of complex structure copper alloy heat exchangers, tail nozzles and other parts . However, due to the excellent thermal conductivity and reflectivity of copper, the absorption rate of copper metal during laser melting is low, and it is difficult for the laser to continuously melt the copper metal powder, resulting in low forming efficiency and difficult control of metallurgical quality.
However, copper-based alloy 3D printing materials and new 3D printing lasers are driving the development of copper metal 3D printing technology. Recently, SLM Solutions, a metal 3D printing company, has verified that CuNi2SiCr, a copper alloy material used for laser melting 3D printing in selected areas, has established ideal printing parameters for this material.
Heat treatment to further increase strength and conductivity
The copper alloy CuNi2SiCr material is compatible with all SLM Solutions laser melting 3D printing systems and is a heat-hardenable alloy with high stiffness and a balanced combination of electrical and thermal conductivity. The alloy includes nickel and silicon components, and has high corrosion resistance and wear resistance.
SLM Solutions identified and parameterized the CuNi2SiCr copper alloy material and established the ideal printing parameters for this material. When testing these parameters, the main problem of copper alloys is the sensitivity to oxygen. To solve this problem, SLM Solutions recommends that when using this material, the maximum oxygen content in the system is 500 ppm.
The conductivity of 3D printed copper alloy materials is usually lower than that of pure copper (IACS value is 100%). After heat treatment of SLM Solutions’ CuNi2SiCr material, the IACS value is increased from 14% when printing is completed to 40%, although the conductivity is lower than Pure copper, but still suitable for some conductive applications.
According to SLM Solutions, the electrical conductivity of copper alloy materials will decrease with the increase in the number of alloy elements, but other properties (such as strength) can be improved, and the strength of CuNi2SiCr materials is better than pure copper. The performance of CuNi2SiCr 3D printed parts can be improved by implementing heat treatment processes, such as precipitation strengthening to make parts have higher strength and electrical conductivity.
The CuNi2SiCr copper alloy 3D printing material is suitable for mold manufacturing, electrical engineering, conductive contacts, welding nozzles, valves and other fields. The strength, resistance and electrical conductivity of CuNi2SiCr materials make it very suitable for manufacturing conductive parts in mechanical, thermal and frictional stress environments.
Compared with the traditional manufacturing process, the combination of CuNi2SiCr material and metal 3D printing technology in achieving design freedom can unlock more new applications that traditional processes cannot achieve, including the design and manufacture of copper with complex internal geometry and topology optimization Alloy parts eventually result in lighter, more cost-effective parts.
The rapid development of metal powder materials is an important driving force for the development of metal 3D printing technology. From the perspective of printing materials, the price of titanium alloy materials is expected to be greatly reduced, the emergence of new stainless steel alloys, the emergence of high-strength and low-price aluminum alloy materials, and the development of copper alloy powder bed laser melting technology and applications will be in the field of additive manufacturing. Ushering in a new era of titanium alloy, aluminum alloy, copper alloy and composite materials manufacturing.