Investigating the influence of the scanning rotation angle on the microstructure and properties of LPBFed CuCr0.8 alloy

Abstract

The fabrication of high-strength and high-conductivity (HSHC) copper alloys by laser powder bed fusion (LPBF) has attracted great interest in recent years. Owing to the excellent strength and high electrical and thermal conductivity of HSHC copper alloy. Moreover, the characteristics of LPBF are suitable for fabricating HSHC. In this paper, the QCr0.8 copper alloy samples with four scanning rotation angles of 0°, 67°, 90°, and 105° were fabricated by LPBF using the high laser power of 2000 W. The results indicate that the scanning rotation angles have no significant influence on the relative density. When the scanning rotation changes to 0°, 67°, 105°, and 90°, the order of the grain size is from large to small. With the 90°scanning rotation angle, the as-built sample has the smallest ultimate tensile strength (UTS) and electrical conductivity. After direct aging, its UTS up to 468.0 Mpa and electrical conductivity is up to 98.3 %IACS. Equally, as a result of precipitation strengthening, the UTS of samples with different scanning rotation angle all increase significantly. This study is to provide theoretical guidance and reference for the selection of scanning rotation angles in the HSHC alloy fabrication process.