摘要
采用光学显微镜(OM)、拉伸试验、硬度测试、SEM断口分析等研究了不同时间深冷处理对Al-7Si-2Cu-0.3Mg合金组织及力学性能的影响。结果表明:对铸态Al-7Si-2Cu-0.3Mg合金进行520℃×6 h固溶+-196℃不同时间深冷+160℃×6 h时效处理试验,随着深冷时间的增加,合金的抗拉强度和硬度逐渐增加,伸长率逐渐降低,抗拉强度和硬度在深冷22 h前提升明显。固溶+22 h深冷+时效处理合金的抗拉强度、硬度分别为351.2 MPa、135.5 HB,比固溶+时效处理合金分别提高了10.1%和8.4%。随着深冷处理时间的增加,合金晶粒尺寸先减小后增大,固溶+22 h深冷+时效处理合金的晶粒较为均匀细小,深冷处理有效改善了合金的组织。
The effects of different time of cryogenic treatment on the microstructure and mechanical properties of Al-7 Si-2 Cu-0.3 Mg alloy were studied by means of optical microscope(OM), tensile test, hardness test, SEM fracture analysis and so on. The results show that when the cast Al-7 Si-2 Cu-0.3 Mg alloy is treated with 520 ℃×6 h solid solution+cryogenic cooling at-196 ℃for different time +160 ℃×6 h aging treatment, with the increases of the cryogenic cooling time, the tensile strength and hardness of the alloy increase gradually, the elongation decreases gradually. The tensile strength and hardness increase significantly before 22 h of cryogenic cooling. The tensile strength and hardness of the alloy treated by solution+22 h cryogenic cooling+aging are 351.2 MPa and 135.5 HB respectively, which are 10.1% and 8.4% higher than that of the alloy treated by solution+aging. With the increases of cryogenic treatment time, the grain size of the alloy decreases first and then increases. The grain size of the alloy treated by solution+22 h cryogenic+aging treatment is relatively uniform and fine. The cryogenic treatment effectively improves the microstructure of the alloy.
作者
孙梅
熊能
周永芳
SUN Mei;XIONG Neng;ZHOU Yongfang(School of Meghanigal and Electrical Engineering,Central South University,Changsha 410083,China;Department of Mechanical and Electrical Engineering,Changde Vocational and Technical College,Changde 415000,China)
出处
《热加工工艺》
北大核心
2020年第10期92-94,共3页
Hot Working Technology
基金
湖南省教育厅科学研究项目(19C0243)
湖南省教育厅科学研究项目(13C602)。
