Hot Compression Deformation Behavior of Spray-Formed AlSn20Cu Alloy

The hot deformation behavior of spray-formed AlSn20Cu alloy during hot compression deformation was studied, and the constitutive equation of AlSn20Cu alloy was established. The samples of spray-formed AlSn20Cu alloy were compressed on Gleeble-3500 thermal simulation test machine. The error of the true stress caused by adiabatic heating effect in the experiment was corrected. The constitutive equation of spray-formed AlSn20Cu alloy could be represented by Zener-Hollomon parameter in a hyperbolic sine function. The results showed that the deformation temperatures and strain rates had a notable effect on the true stress of the alloy. At the identical deformation temperature, the true stress increased with the increase of strain rate. When the strain rate was constant, the stress decreased with the increase of deformation temperature. After hot compression deformation, the tin phase was elongated along the direction perpendicular to the compression axis with short strips and blocks. With the increase of deformation temperature and the decrease of strain rate, Sn phase distribution became more homogeneous.

Evolution of Microstructure, Texture, and Mechanical Properties of As-Extruded ND/ZK60 Composite during Hot Compression Deformation

The effects of temperature, strain rate, and strain on the microstructure, texture, and mechanical properties of as-extruded nanodiamond reinforced ZK60 composite during hot compression was systematically studied. The results revealed that the precipitating MgZn2 and the nanodiamond (ND) particles distributed in the grain interiors hindered the motion of dislocations. The ND particles act as nucleation points and promote the dynamic recrystallization (DRX) of the composites during the hot compression deformation, the flow stress of ND/ZK60 increases with strain rate increases and temperature decreases. {101¯2} extension twins are nucleated and grown in the coarse grains as the compressive strain increasing. Meanwhile, the fine grains of DRX generate and present first an increasing then a decreasing trend. The result of Schmid factor and kernel average misorientation indicates that high-density dislocation caused by dislocation climbing and cross slip aggregated in composites with increasing strain. Therefore, the work hardening trend of the composite is strengthened.