Effect of Ratcheting Strain on Mechanical Properties of Additive Manufactured 4043 Aluminum Alloy

摘要

4043 aluminum alloy was printed by cold metal transfer (CMT) additive manufacturing (AM) technology. The microstructure and mechanical properties were analyzed. The effect of ratcheting behavior was analyzed by the tensile test after ratcheting. The results indicate that the dendrite structure of 4043 aluminum alloy has obvious directivity. The binary eutectic structure of a (Al) + Si is mainly distributed at the grain boundaries and the interior of grain is mainly a (Al). The increase of stress amplitude and mean stress leads to ratcheting strain, which can cause plastic damage of AM aluminum alloy. This is related to holes aggregation and dislocation slip caused by ratcheting behavior. Compared to the aluminum alloy of un-ratcheted test, the tensile and yield strength increase and the elongation decrease, but the change of tensile and yield strength are not obvious between the specimens of different ratcheting.