【作者】 吕兰兰；

【导师】 程晓敏； 李启友；

【作者基本信息】 武汉理工大学 ， 材料学， 2006， 硕士

【摘要】 铸造铝硅合金由于其良好的铸造性能成为铝合金中使用较多、应用范围较广的一种合金系，其中ZL107合金除了具有良好的铸造性能之外，还具有较好的气密性等综合性能，因而成为工业应用较广的合金之一。由于普通ZL107合金的力学性能较差，尤其是韧性较差，无法满足某些性能要求较高的零部件的需求，因而限制了该合金在铸件上的应用范围。如何保持ZL107合金优良铸造性能的同时，不断提高其综合力学性能，扩大其使用范围，始终是材料工作者面临的课题。 本课题从铝合金强韧化理论出发，通过添加合金元素进行成分优化设计，采用正交试验法对ZL107合金中Ti、Cd、Zn含量及Sb变质进行优化实验研究。试验中采取不同的热处理工艺，并根据力学性能测试和正交试验结果，考察合金元素加入量、变质剂加入量和热处理工艺对ZL107合金性能的影响并得出最优化的实验结果。同时，本文还考察了Na变质与Sb变质的区别及合金元素Ag的加入对合金性能的影响。 实验结果表明，经过优化设计后的合金成分(wt％)为：在ZL107的基础上添加0.116％Ti，0.116％Cd，0.043％Mg，0.916％Zn；优化变质剂为：采用占炉料质量2.5％的三元Na盐(25％NaF+62％NaCl+13％KCl)变质剂；合适的热处理工艺为：固溶处理为515℃保温5小时后70℃水淬，时效处理为150℃保温11小时后空冷。 经上述优化设计和合适工艺处理后的合金，其力学性能得到大幅度提高，即抗拉强度σ_b=360.6MPa，延伸率δ=3.65％，硬度HB=117。因此该铸造铝合金具有比普通ZL107更优越的力学性能，可以更大程度地满足现代工业生产应用的要求，具有广阔的应用前景。更多还原

【Abstract】 Casting aluminium-silicon alloy is the most widely used aluminium alloy due to its good casting property. ZL107 alloy is one of the widely used alloys in industry since it has not only good casting characteristics but also good air seal property. As the mechanical properties of common ZL107 alloy, especially the ductility, is relatively worse and cannot meet the need of use of some important parts, the application of common ZL107 alloy is limited. So it has been a proposition of material researchers that how to improve the mechanical properties of common ZL107 alloy.This paper starts from the theory of improving the strength and toughness of aluminium alloy. A new kind of casting aluminium, silicon and copper alloy was obtained and the mechanical properties of the alloy are much better than the common ZL107 alloy by adding alloying elements and optimizing experiment method. The addition amount of Ti、 Cd、 Zn and Sb modification were optimized by orthogonal test. Different heat treatment processes were also taken into account. The effect of alloy elements, modification and heat treatment on the mechanical properties of the alloy was investigated and the optimal process parameters were obtained by the results of orthogonal test. The difference between Sb modification and Na modification and the effect of Ag has also been studied.Results show that the optimal chemical composition of the alloy is (wt%): ZL107, 0.116%Ti, 0.116%Cd, 0.043%Mg, 0.916%Zn . The better modification is salt Na (25%NaF+62%NaCl+13%KCl) which is 2.5% of the total of the melting alloy. The appropriate heat treatment process is 515°Cx5h quenching in 70°C water and 150℃x11h aging.The mechanical properties of the alloy treated by the above process can be improved greatly. That is, tensile strength σ_b=360.6MPa, elongation rate δ =3.65%, hardness HB=117. In comparison with common ZL107 alloy, the optimal aluminium alloy possesses much better mechanical properties and can be more widely used in industry and meet the needs for a lot applications.更多还原