时效对铸造Al-Si-Cu-Mg合金力学性能和耐蚀性能的影响
Effect of aging on mechanical properties and corrosion resistance of Al-Si-Cu-Mg cast alloy
夏琳燕 1史湘琴 2刘逸卿 2周模豪 1邓蔚1
作者信息
- 1. 长沙学院机电工程学院,湖南长沙 410022
- 2. 长沙学院机电工程学院,湖南长沙 410022;武汉理工大学材料科学与工程学院,湖北武汉 100083
- 折叠
摘要
研究了单级、双级时效对铸造Al-Si-Cu-Mg合金显微组织、力学性能和耐腐蚀性能的影响.结果表明,铸造Al-Si-Cu-Mg合金时效后的显微组织主要由α-Al基体和共晶Si相构成.单级时效处理(170 ℃ ×10 h)后合金的峰值硬度为151.8 HV0.1,抗拉强度和屈服强度分别为287和252 MPa,伸长率为10.6％,但其耐腐蚀性能较差,最大晶间腐蚀深度达到113.3 μm.与单级时效相比,双级时效(90 ℃ ×3 h+170 ℃ ×4 h)可显著改善铸造Al-Si-Cu-Mg合金的力学性能和耐腐蚀性能,其峰值硬度提高了 5.7％,抗拉强度和屈服强度分别提高了 4.5％和6％,伸长率提高了两倍以上.此外,合金的耐腐蚀性能也得到了改善,最大晶间腐蚀深度为60.0 μm.合金获得较高力学性能和良好的耐腐蚀性能主要取决于均匀、细小的Si相,且灰黑色针状β相与黑色块状组织也相对较少.
Abstract
Effect of aging treatment(single aging and two-step aging)on the microstructure,mechanical properties and corrosion resistance of Al-Si-Cu-Mg cast alloy was studied.The results show that the microstructure of the Al-Si-Cu-Mg cast alloy after aging is composed of α-Al matrix and eutectic Si phase.After single aging at 170 ℃ for 10 h,the peak hardness of the alloy is 151.8 HV0.1,the tensile strength and yield strength are 287 MPa and 252 MPa,respectively,and the elongation is 10.6％.However,the corrosion resistance is poor,and the maximum intergranular corrosion depth reaches 113.3 μm.As compared with that after the single aging,after the optimized two-step aging at 90℃for 3 h and 170 ℃ for 4 h,the mechanical properties and corrosion resistance of the tested alloy are greatly improved.The peak hardness is increased by 5.7％,and the tensile strength and yield strength are increased by 4.5％and 6％,respectively.Moreover,the elongation is increased more than twice.The corrosion resistance improves,and the maximum intergranular corrosion depth is reduced to 60.0 μm.The fine and uniform Si phase and relatively less gray-black acicular β phase and black block structure are responsible for the improvement of mechanical properties and corrosion resistance of the tested alloy.
关键词
铸造Al-Si-Cu-Mg合金/双级时效/力学性能/耐腐蚀性能Key words
Al-Si-Cu-Mg cast alloy/two-step aging/mechanical properties/corrosion resistance引用本文复制引用
基金项目
湖南省教育厅科学研究项目(21C0757)
出版年
2024
NETL
NSTL
万方数据