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Al-Si-Fe基铝合金材料由于具有高耐磨性、低密度以及低热膨胀性能,因而主要用于汽车发动机部件。利用气体雾化粉末,采用放电等离子体烧结技术制备Al-17Si-5Fe-2Cu-1Mg-1Ni-1Zr合金。所制备材料的晶粒尺寸为530 nm,并且观察到细等轴晶粒和均匀分布的析出物。研究了放电等离子体烧结技术制备的材料在不同温度和应变速率下的压缩变形行为。结果表明,所有的真应力-真应变曲线在达到峰值应力后呈稳态流动趋势,随着测试温度的升高和应变速率的降低,峰值应力呈下降趋势。在变形样品中,观察到了等轴晶粒和等轴晶粒中的位错结构。这些现象说明,合金在高温变形过程中发生了动态再结晶。
Al-Si-Fe based aluminum alloy materials are mainly used in automotive engine parts because of their high wear resistance, low density and low thermal expansion. Al-17Si-5Fe-2Cu-1Mg-1Ni-1Zr alloy was prepared by gas-atomized powder and spark plasma sintering technique. The prepared material had a grain size of 530 nm and fine equiaxed grains and uniformly distributed precipitates were observed. The compressive deformation behavior of materials prepared by spark plasma sintering at different temperatures and strain rates was studied. The results show that all the true stress-true strain curves show a steady-state flow trend after reaching the peak stress. With the increase of the test temperature and the decrease of the strain rate, the peak stress decreases. In the deformed samples, dislocation structures in equiaxed grains and equiaxed grains were observed. These phenomena indicate that the alloy undergoes dynamic recrystallization during high temperature deformation.