摘要
采用室温拉伸实验、金相组织观察和扫描电镜观察研究了复合变质处理和T6热处理对过共晶Al-18Si-4Cu-0. 5Mg合金力学性能和显微组织的影响。结果表明,过共晶Al-18Si-4Cu-0.5Mg合金经P-RE-Sr复合变质处理后,初晶硅由粗大不规则板块状细化为细小片状,尺寸明显减小,共晶硅由细长针状转变为珊瑚状、短棒状和蠕虫状,经T6热处理后,初晶硅尺寸无明显变化,共晶硅发生熔断、球化;经P-RE-Sr复合变质处理后,抗拉强度由222MPa提高至236MPa,延伸率由3.22%提高至4.03%;复合变质合金经T6热处理后,抗拉强度大幅度提高,提高至320MPa,但延伸率略有下降,下降至3.37%。
In this paper, the effects of complex modification and T6 heat treatment on microstructure and mechanical properties of Al-18Si-4Cu-O.SMg alloy are studied by means of room temperature tensile test, metallographic observation and SEM observation. The results indicats that primary Si is refined from coarse irregular polygonal shape to fine flake shape, and eutectic Si is significantly modified from coarse needle-like to fine rod-like and coral-like after P-RE-Sr complex modification. However, primary Si has no obvious change and eutectic Si is dissolved and broken and spheroidized with T6 heat treatment. The ultimate tensile strength is increased from 222 MPa to 236 MPa and the elongation is increased from 3.22% to 4.03% after P- RE-Sr complex modification. After T6 heat treatment, the tensile strength of the composite modified alloy is greatly improved to 320MPa, but the elongation decreased slightly to 3.37%.
作者
李坤
冯永平
刘金霞
张婷蕊
林高用
Li Kun;Feng Yongping;Liu Jinxia;Zhang Tingrui;Lin Gaoyong(School of Material Science and Engineering,Central South University,Changsha 410083,China;Fujian Xiangxin Co.,Ltd.,Fuzhou 350000,China)
出处
《有色金属加工》
CAS
2018年第6期12-17,共6页
Nonferrous Metals Processing
基金
国家自然科学基金项目资助(51274245)
