机构地区: 中南大学材料科学与工程学院
出 处: 《中国钼业》 2007年第1期34-37,共4页
摘 要: 采用力学性能测试、X射线衍射物相分析、SEM观察研究了时效对固溶-冷拉处理后的Sn、Bi微合金化的新型无铅易切削6xxx系Al-Mg-Si合金棒材微观组织和力学性能影响,并比较了该合金与6262合金的切削性能。结果表明:其最佳的时效热处理工艺为170℃/10 h,在此工艺条件下,抗拉强度为348 MPa,屈服强度为339MPa,延伸率为12.5%。峰时效态合金的物相组成为Al基体,主要强化相Mg2Si,低熔点物质Mg2Sn、Mg3Bi2和Bi及少量的CuAl2相。切削性能试验表明,用Sn和Bi微合金化6xxxAl-Mg-Si合金的切削性能比Pb和Bi微合金化的传统6262合金稍好。 The effect of aging treatment on the microstructure and mechanical properties of solution treated and cold drawn Sn and Bi alloying new lead - free free - cutting 6xxx A1 - Mg - Si alloy rod was investigated using mechanical property test, XRD analysis and SEM observation. The results show that the best aging process is 170℃/10 h. In this condition, the tensile strength, yield strength and elongation of the alloy bar can get 348 MPa, 339 MPa, 12. 5% respectively. The phase composition of alloy with aging treatment include Al - based solid solution, low melting point phase (MgESn and Mg3 Bi2, Bi), MgESi precipitates, and little CuAl2. Machinablity test shows that the machinablity of Sn and Bi alloying lead - free free - cutting 6xxx Al - Mg - Si alloy is better than conventional Pb and Bi alloying 6262 alloy.