Cold spray additive manufacturing of CCZ—a study on the microstructure, mechanical, and plasma sputter erosion properties
摘要
Copper-chromium-zirconium (CCZ) is a promising material due to its high thermal conductivity and mechanical strength, even at elevated temperatures. Previous studies on additive manufacturing (AM) of CCZ have mainly focused on laser or electron-beam processes. However, these methods have drawbacks such as poor laser absorption, inferior surface finish, high porosity, the need for a vacuum environment, and slow deposition rates. This study explores the potential of cold spray (CS) for rapidly creating dense, centimeter-scale CCZ deposits in a solid state with minimal oxidation. It demonstrates the successful fabrication of a 2.5 cm-thick and dense CCZ deposit on an aluminum cylinder, with minimal porosity. The residual oxide content of the bulk CCZ deposit was measured using Glow Discharge Optical Emission Spectroscopy (GDOES). Additionally, GDOES was used to determine the plasma sputter erosion rate of CSed CCZ, which was found to be 1.25 g/m²s. Mechanical property assessments showed promising results: hardness was 173 HV0.3, and strength reached 470 MPa with an average deformation of 12.36%. These are comparable to those of bulk-manufactured CCZ. Electron microscopy and atom probe tomography studies indicated that the excellent properties of the deposit originate from the preferential segregation of chromium (Cr) and zirconium (Zr) at the grain boundaries. This segregation leads to a pinning effect, contributing to the observed strengthening of the CCZ in the as-deposited condition. The finding shows the excellent potential of CS for bulk manufacturing of CCZ with favourable microstructures, leading to appreciable ductility and excellent mechanical properties.