Papers by Author: Wen Xian Li

Abstract: By detecting microstructures and properties of Cu-W composites, effects of powder composition, sintering temperature and compacting pressure on sintered billets were studied, and sintering mechanism of Cu-W powders was discussed. Effective rules of process parameters have been preliminarily obtained: Sintered billets of Cu-40W and Cu-50W had a low density when compacted at 200MPa, sintered below the melting point of copper, and density, hardness enlarged with sintering temperature increasing; Hardness, density, electrical conductivity of Cu-40W enlarged with compacting pressure when compacted above 600MPa, sintered at 1100°C; But when compacted at 800MPa, sintered at 1100°C, Cu-40W sintered billets had a density of 11.37g/cm3, relative density of 99.6%, closed to the theoretical value.

Abstract: The hot compression simulation of an experimental Mg-Zn-Nd alloy at different temperatures is studied by the Gleebe-1500 equipment. The deformation is performed with the strain rates 0.1s-1, 0.01s-1 and 0.002s-1. The plastic deformation behavior is analyzed at different temperatures and the deformation activation energy is calculated. The microstructures of experimental alloy during the deformation process are observed. The results show that the working hardening, dynamic recovery and dynamic recrystallization (DRX) operate under different temperatures and strain rate. The DRX starts when the temperature is over 473K and the DRX grain size after hot deformation is only 5~10μm. So the refined grains improve both the tensile strength and elongation of alloys at room temperature. The precipitate phase Mg12Nd impede the movement of dislocations, it benefit to the mechanical properties and grain refining of magnesium alloy.