范梦婷1 罗欣然2 房庆生2 王 轩3
(1.重庆城市职业学院建筑工程系； 2.重庆大学材料学院； 3.重庆文理学院土木工程学院)
摘 要：研究了固溶和时效热处理对挤压铸造6063铝合金显微组织和力学性能的影响，并分析了热处理工艺参数的影响机理。结果表明，随着固溶时间从15 min增加至120 min，6063铝合金中晶粒尺寸不断变大，晶界和晶内Mg2Si相逐渐消失并回溶至基体，而固溶时间对α-Al8Fe2Si和β-Al5FeSi相影响较小，合金的强度和硬度则表现为先增大后减小，伸长率表现为先减小后增大的特征；当时效温度从160 ℃增加至180 ℃，6063铝合金中第二相逐渐增多，而时效温度为200 ℃时合金中第二相会发生粗化，6063铝合金的强度和硬度会随着时效温度升高而先增加后减小，伸长率则随着时效温度升高先减小后增大；时效时间在3 h及以下时，6063铝合金中次生第二相数量较少，当时效时间增加至5 h时，弥散分布的第二相会逐渐增多，在时效时间达到12 h及以上时第二相发生明显粗化与长大；6063铝合金适宜的热处理制度为535 ℃×60 min+180 ℃×7 h，此时6063铝合金具有最大的强度、硬度以及较高的伸长率。
Effect of Heat Treatment on Microstructure and Properties of Squeezing Casting 6063 Aluminum Alloy
Fan Mengting1, Luo Xinran2, Fang Qingsheng2, Wang Xuan3
(1.Department of Architecture and Civil Engineering, Chongqing City Vocational College; 2.School of Materials, Chongqing University; 3.College of Civil Engineering, Chongqing University of Arts and Science)
Abstract: The effects of heat treatment (solution and aging) on the microstructure and mechanical properties of 6063 aluminum alloy were investigated, and the roles of heat treatment process parameters were analyzed. The results show that with the increase of solution time from 15 min to 120 min, the grain size in the 6063 aluminum alloy is coarsened continuously, and the primary phase of Mg2Si in grain boundary and crystal disappears gradually and is dissolved into the matrix, while the effect of solution holding time on α-Al8Fe2Si and β-Al5FeSi phases can be ignored. Meanwhile, the strength and hardness of the alloy are increased firstly and then decreased, while the elongation is decreased firstly and then increased. When the aging temperature is increased from 160 ℃ to 180 ℃, the second phase in 6063 aluminum alloy is increased gradually, while the second phase in 6063 aluminum alloy is coarsened at 200 ℃, so the strength and hardness of 6063 aluminum alloy are increased firstly and then decreased with the increase of aging temperature, and the elongation is decreased firstly and then increased. When the aging holding time is 3 h or less, the amount of secondary phase is declined in 6063 aluminum alloy, while with the aging holding time of 5 hours or more, the number of dispersed second phase will be gradually increased, and obvious coarsening and growth of the second phase will occur when the aging holding time is 12 h or more. The suitable heat treatment process of 6063 aluminum alloy is 535 ℃×60 min+180 ℃×7 h, where the 6063 aluminum alloy has the maximum strength, hardness and higher elongation.
Key Words: 6063 Aluminum Alloy, Heat Treatment, Microstructure, Properties