Effect of aging process on the microstructure and nanowear properties of laser powder bed fusion (LPBF)-produced copper alloy
摘要
The CuCrZr alloy is utilized as a power transmission component in microelectronics applications. Notably, nano-sized wear primarily occurs during the charging process of microelectronics. This study investigated the nanowear characteristics of the LPBF CuCrZr alloy when subjected to varying operational load conditions. The aging process was conducted at temperatures of 250 °C, 450 °C, and 650 °C for a duration of 120 min. The specimens aged at 250 °C exhibited a closely packed columnar structure, while the specimens aged at 450 °C and 650 °C developed an equiaxed structure. In addition, nanohardness tests were performed on all three specimens using loads of 2500 µN, 5000 µN, and 7500 µN. The analysis indicated that the columnar structure from the 250 °C aging exhibited an equivalent reaction to the indenter, resulting in material piling up. In contrast, the equiaxed structure in the specimens aged at 450 °C and 650 °C compressed more and showed less reaction against the indenter. A nanowear test at a constant load of 3500 µN was also conducted on all three aging specimens. The results showed that the equiaxed structure from the 650 °C aging was unable to resist the tangential force of the indenter due to local shear. However, the closely packed columnar structure from the 250 °C aging effectively opposed the tangential force, leading to the formation of abrasive grooves on the worn surface. Furthermore, the coefficient of friction decreased with increasing aging temperature. The wear mechanisms identified included two-body and three-body abrasive wear at the 250 °C aging specimen, while the ploughing wear mechanism was observed in the specimens aged at 450 °C and 650 °C.