不同Cu含量对Al-Si-Mg-Er-Zr合金室温及高温力学性能的影响  

Effects of Cu Contents on Mechanical Properties of Al-Si-Mg-Er-Zr Alloy at Room Temperature and High Temperature

作　　者：马晨曦 荣莉[1] 魏午 黄晖[1] 代钊 王泽忠 周力 Ma Chenxi;Rong Li;Wei Wu;Huang Hui;Dai Zhao;Wang Zezhong;Zhou Li(College of Materials Science and Engineering,Beijing University of Technology,Beijing 100124,China;Kingdream Public Co.,Ltd,Wuhan 430000,China;Dongfeng Automobile Group Co.,Ltd,Wuhan 430056,China)

机构地区：[1]北京工业大学材料科学与工程学院,北京100124 [2]中石化江钻石油机械有限公司,武汉430000 [3]东风汽车集团股份有限公司,武汉430056

出　　处：《稀有金属材料与工程》2024年第10期2960-2967,共8页Rare Metal Materials and Engineering

基　　金：国家重点研发计划(2021YFB3700901,2021YFB3700902)。

摘　　要：研究了Cu含量对Al-Si-Mg-Er-Zr合金室温及高温拉伸性能的影响。不同Cu含量合金铸态组织均存在α-Al、Si相、β相、Q相、θ相。随Cu含量的增加,合金中共晶组织增多,呈骨骼状,这有利于提升合金的铸造性能。随Cu含量增加,铸态合金的屈服强度提高。对3种Cu含量(0.6Cu、1.0Cu、1.4Cu)的Al-Si-Mg-Er-Zr合金进行500℃/4 h+540℃/2 h+180℃/x h热处理,它们分别在10、12、12 h达到峰值时效,峰值硬度(HV)分别为1344.6、1364.2、1398.5 MPa。随Cu含量增加,合金T6态室温拉伸强度提高,这是由于时效过程中含1.4Cu的合金中存在的强化相最多,包含β''相、Q'相、θ'相这3种相。在300℃高温暴露44 h后,含1.4Cu的合金硬度降幅最小。这是由于在该温度下,合金中随Cu含量增加,棒状Q相也增加,而Q-Al_(5)Mg_(8)Cu_(2)Si_(6)相是合金中主要的热力学稳定的强化相,提高了合金的耐热性。经T6处理的3种Cu含量的合金,在300℃高温拉伸的延伸率比室温拉伸的延伸率高,断裂形式也从室温拉伸的脆性断裂转变成韧性断裂。The effect of Cu content on the tensile properties of Al-Si-Mg-Er-Zr alloy at room temperature and high temperature was studied.Results show that there areα-Al,Si,β,Q andθphases in the as-cast Al-Si-Mg-Er-Zr alloys with different Cu contents.With the increase in Cu content,the eutectic microstructure of the alloy increases,and it is bone-shaped,which is conducive to improving the casting performance of the alloy.With the increase in Cu content,the yield strength of as-cast alloys increases.Three Al-Si-Mg-Er-Zr alloys with different Cu contents(0.6Cu,1.0Cu and 1.4Cu)were heat treated under 500℃/4 h+540℃/2 h+180℃/x h,and they reach peak aging at 10,12 and 12 h with the peak hardness(HV)of 1344.6,1364.2 and 1398.5 MPa,respectively.With the increase in Cu content,the room temperature tensile strength of the alloys under T6 temper increases,which is due to the fact that the alloy containing 1.4%Cu has the most strengthening phase,includingβ″phase,Q′phase andθ′phase.After 44 h of soaking at 300℃,the hardness of the alloy containing 1.4%Cu decreases the least.This is because with the increase in the Cu content,the amount of the Q-Al_(5)Mg_(8)Cu_(2)Si_(6)precipitates increases,and the Q-Al_(5)Mg_(8)Cu_(2)Si_(6)phase is the main thermo-dynamically stable precipitate at 300℃,improving the heat resistance of the alloy.The elongation at 300℃of the three Cu alloys under T6 temper is higher than that at room temperature,and the fracture form also changes from brittle fracture at room temperature to ductile fracture at 300℃.

关 键 词：CU含量 Al-Si-Mg-Er-Zr合金 时效强化 力学性能 耐热性 

分 类 号：TG146.21[一般工业技术—材料科学与工程]