纳米铜粉对高速压制铁基粉末冶金零件性能的影响

Efect of copper nanoparticles on strengthening of iron base P/M parts formed by high velocity compaction

研究了用高速压制技术制备的纳米铜粉增强铁基合金制品的性能．在保持原料中铜粉总质量分数1．5％不变的情况下，将部分或全部微米级铜粉替换成纳米级铜粉，并通过高速压制技术制备了七种纳米铜粉质量分数分别为0、0．25％、0．50％、0．75％、1．00％、1．25％和1．50％的铁基合金制品试样，随后压坯于1150℃下烧结2h．研究发现铁基合金烧结制品的组织和性能得到改善，且尺寸精度得到有效控制．当纳米铜质量分数为0．75％时，烧结态合金的抗拉强度和硬度分别达到720．6MPa和94．7HRB．纳米铜质量分数为0．25％－1．5％时，所得试样的轴向和径向收缩率分别在0．4％－0．7％和-0．09％～-0．23％之间．

Cu nanopowders were used to improve the performance of iron based alloy products formed by high velocity compaction. Under the condition that Cu powders were remain unchanged as a constant of 1.5%, part or all of Cu micropowders were replaced by Cu nanopowders. Seven kinds of iron-based alloy product samples in which the mass fractions of Cu nanopowders were 0- 0.25%, 0.50%- 0.75%, 1.00%, 1.25% and 1.50% respectively were prepared by high velocity compaction. The green compacts were sintered at 1150 ℃ for 2 h subsequently. It is found that the microstructure and performance of the iron base P/M parts is improved and the dimensional accuracy is also effectively controlled with the addition of Cu nanopowders. The tensile strength and hardness of the sintered alloy which contains 0.75% of Cu nanopowders are 720.6 MPa and 94.7 HRB, respectively. The axial and radial shrinkages of the obtained samples are in the ranges of 0.4% to 0.7% and -0.09% to -0.23% respectively when the mass fraction of Cu nanopowders is from 0.25% to 1.50%.