新型团球硅相增强锌铝合金的研究

Research on New Silicon-reinforced Zn-Al Alloys

选择多种成分的锌铝合金，以硅为增强相，扩大硅的成分范围，采用复合钠盐和稀土混合物对合金中的硅进行变质处理，测定试验合金的力学性能和常温、高温耐磨性，优选综合力学性能较好的试样，进行离心铸造、轴瓦抱轴和高温磨损测试，观察其显微组织。结果表明，锌铝合金中加入硅相后，其综合力学性能进一步提高，采用钠盐和稀土混合变质，两者的变质作用互相促进。根据离心铸造测试结果，建议转速在500600r／min之间为好，硅相的浓度分布是从铸件外层到内壁逐渐增大，优选合金的使用温度比ZA27合金明显提高，这归功于硅相的骨架作用。

This paper studies new silicon-reinforced Zn-Al Alloys in large composition range, as the silicon phase are modified with sodium salt compounds and rare metal oxides. Research process tests the mechnical properties（e, g. tenacity, hardness, tensile strength and wear-resistance）, disicusses the transformation mechanism of modifier, and selects the better alloy for further testing of centrifugal forge, axis-tile holding, wear-resistance at high temperature and observing of microstructure, the results show that the effects of sodium salt compounds and rare metal oxides on silicon phase promote each other, mechnical properties of silicon-reinforced Zn-Al Alloys are improved, and for the selected alloy, stratification does not appear as the rotate speed of centrifugal forge is below 500 r/min, but the compositions of silicon decreases gradually from outer to inner along radial section. The use temperature of selected alloy is higher than ordinary ZA27 due to the frameworks formed by silicon.