T6热处理对粉末触变成形技术制备Ti@(Al-Si-Ti)p/A356Al复合材料组织和性能的影响  

Effect of T6 Heat Treatment on Microstructure and Properties of Ti@(Al-Si-Ti)p/A356Al Composites Fabricated via Powder Thixoforming

作　　者：张治国 陈体军[1,2] 张学拯[1,2] 王延明 Zhang Zhiguo;Chen Tijun;Zhang Xuezheng;Wang Yanming(School of Material Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China;State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]兰州理工大学材料科学与工程学院,甘肃兰州730050 [2]兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室,甘肃兰州730050

出　　处：《稀有金属材料与工程》2024年第2期520-528,共9页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51564035)。

摘　　要：采用粉末触变成形技术制备了由“芯-壳”结构粒子增强的A356Al复合材料,然后通过T6热处理进一步提高该复合材料的综合力学性能。结果表明,“芯-壳”结构增强体颗粒不仅能够提高复合材料的抗拉强度、屈服强度(增加率分别为18.0%和32.7%),延伸率10.8%,具备与基体铝合金(12.4%)相当的塑性。在T6热处理过程中,随时效时间的延长,该复合材料的强度、硬度先增加(1~7 h,即欠时效)后减小(9~12 h,即过时效),在8 h时达到最大值(即峰时效),此时复合材料的抗拉强度、屈服强度和硬度分别为325.4 MPa、254.4 MPa和1019.2 MPa,比热处理前分别提高了33.7%、74.0%和48.5%;峰时效延伸率为9.4%,与热处理前相比几乎没有下降。即经过T6热处理后,“芯-壳”结构增强体粒子能在提高复合材料强度的同时,最大程度地保留其良好的塑性。最后,分析了时效8和12h的复合材料基体中析出相的尺寸、密度和类型,并对其强化机制进行了讨论。An A356 Al alloy based composite reinforced by core-shell structured(CS)particulates was prepared by powder thixoforming,and then the comprehensive mechanical properties of the composite were further improved by T6 heat treatment.The results show that the CS particulates not only improve the ultimate tensile strength and yield strength of the composite(increased by 18.0%and 32.7%,respectively),but also render the composite an excellent elongation of 10.8%equivalent to that of the A356 alloy(12.4%).During the T6 heat treatment,the strength and hardness of the composite increase firstly(1-7 h,i.e.,under-aging)and then decrease(9-12 h,i.e.,over-aging)with the extension of the aging time,reaching the maximum value at 8 h(i.e.,peak aging).The ultimate tensile strength,yield strength and hardness of the composite at peak aging are 325.4 MPa,254.4 MPa and 1019.2 MPa,respectively,which are 33.7%,74.0%and 48.5%higher than those without the heat treatment,and the elongation is 9.4%,which has almost no decrease compared with that without heat treatment.In other words,after the T6 heat treatment,the CS particulates can improve the strength of the composite while retaining its good plasticity.Finally,the strengthening mechanisms of the composite were discussed by analyzing the size,density and type of the precipitates in the matrix of the composites aged for 8 and 12 h.

关 键 词：铝基复合材料 粉末触变成形 “芯-壳”结构 T6热处理 组织与性能 

分 类 号：TB331[一般工业技术—材料科学与工程]