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用离心技术制得了过共晶Al 2 0Si合金梯度材料 ,离心机转速 14 0 0r/min ,金属模具预热温度 4 5 0℃ ,浇注温度 80 0℃。研究表明 ,在离心力场中初晶Si向试样内侧移动。Al 2 0Si合金梯度材料最内层初晶硅含量最多、尺寸也最大 ,由内向外 ,初晶硅的体积分数及尺寸均逐渐减小 ,呈梯度变化。材料内层硬度较高、耐磨性较好 ,由内向外硬度逐渐减小、耐磨性变差 ,呈梯度变化。
Hypereutectic Al 2 OSi alloy gradient material was prepared by centrifugal technique. Centrifugal speed was 1400 rpm, metal mold preheat temperature was 450 ℃ and pouring temperature was 80 ℃. The results show that the primary Si moves in the centrifugal field to the inside of the specimen. The content of primary Si in the innermost layer of Al 2 OSi alloy gradient material is the largest and its size is also the largest. From the inside to the outside, the volume fraction and the size of the primary Si gradually decrease and the gradient changes. High material inner layer hardness, wear resistance is better, gradually reduced from the inside out hardness, wear resistance deteriorated, showing a gradient change.