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采用离心铸造技术成功地制得了过共晶Al 10 %Fe梯度材料 ,离心机转速每分钟 140 0转 ,金属模具预热温度 4 50℃ ,浇注温度 10 0 0℃。采用金相及扫描电子显微镜、HV 5型小负荷维氏硬度计及销盘式ML 10 0型磨粒磨损试验机研究了梯度材料组织、硬度及耐磨性的分布规律。结果表明由于初晶Al3Fe密度比Al液密度高 ,在离心力场中初晶Al3Fe向试样外侧移动。Al 10 %Fe合金梯度材料的组织分布为最外层初晶Al3Fe含量最多、尺寸也最大 ,由外向内 ,初晶Al3Fe的体积分数及尺寸均逐渐减小 ,且呈梯度变化。在内层一定厚度内 ,完全不含初晶Al3Fe。Al 10 %Fe合金梯度材料的硬度分布为外层硬度较高 ,由外向内硬度逐渐减小 ,呈梯度分布。Al 10 %Fe合金梯度材料试样的耐磨性试验结果表明 ,试样从外到内磨损厚度增大 ,即该梯度材料的耐磨性由外至内呈梯度下降的变化趋势。
The hypereutectic Al 10% Fe gradient material was successfully prepared by centrifugal casting technology. Centrifuge speed was 140 0 rpm, the preheating temperature was 450 ℃ and the pouring temperature was 100 ℃. The distribution of microstructure, hardness and wear resistance of the graded material was studied by metallographic and scanning electron microscopy, HV 5 Vickers hardness tester and pin-type ML 10 0 abrasive wear tester. The results show that the primary crystal Al3Fe moves to the outside of the sample in the centrifugal field due to the high density of the primary crystal Al3Fe. Al 10% Fe alloy gradient material microstructure distribution of the outermost primary crystal Al 3 Fe content is the largest, the largest size, from the outside, the primary crystal Al 3 Fe volume fraction and size gradually decreased, and the gradient changes. Within a certain thickness of the inner, completely free of primary crystal Al3Fe. The hardness distribution of the Al 10% Fe alloy gradient material is that the hardness of the outer layer is higher, and the hardness of the Al 10% Fe alloy gradient gradually decreases from the outside to the inside, with a gradient distribution. The results of wear resistance of Al 10% Fe alloy gradient specimens show that the thickness of the specimens increases from outside to inside, that is, the gradient of the wear resistance of the gradient material changes from outside to inside gradually.