研究目的
Investigating the microstructure evolution and mechanical properties of laser additive manufacturing of high strength Al-Cu-Mg alloy.
研究成果
Al 2024 parts with relative high density of 99.7% and no macro cracks were obtained. The deposition pattern influenced the densification of the DEDed Al 2024 parts. The bidirectional microstructure was denser, and there were pores and cracks in the unidirectional microstructure. Microhardness of 135 HV, UTS of 276 MPa and σ0.2 of 175 MPa was obtained, which was higher than that the cast Al 2024 samples. The microstructure of DEDed Al 2024 was mainly composed of α-Al and CuAl2. Different parts formed different microstructure due to different thermal circulation processes. The orientation of the grains was affected by the scanning direction and deflected with the change of scanning direction. Higher performance can be obtained by means of preheating and power improvement.
研究不足
The study focused on the DED process of Al 2024 alloys, mainly on the microstructure and forming properties of single layer, while DED process of multi-layer has not been well studied. The technical and application constraints include the poor wettability, high thermal conductivity, and high reflectivity of aluminum alloys.
