部分固溶处理对AZ91D镁合金微观组织及力学性能的影响  

Effect of partial solid-solution treatment on microstructure and mechanical properties of AZ91 Dmagnesium alloy

作　　者：马颖[1] 董海荣[1] 张玉福[1] 王永欣[1] 

机构地区：[1]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：《兰州理工大学学报》2015年第6期1-5,共5页Journal of Lanzhou University of Technology

基　　金：973前期专项(2010CB635106)

摘　　要：对AZ91D镁合金进行部分固溶处理,研究其热处理后的组织和性能.结果表明:温度较低时,合金的性能随时间变化不明显.升高温度,硬度随时间延长逐渐降低,而抗拉强度和延伸率逐渐增加.当保温时间一定时,硬度随温度的升高逐渐降低,抗拉强度和延伸率则逐渐增加.部分固溶处理后,晶界处硬脆相β-Mg17Al12部分溶入基体,同时由原来的网状分布变成岛状分布.硬脆相的减少,使得合金的硬度有所下降,但高于完全固溶处理后的硬度,而硬脆相形态的改变,又提高了材料的抗拉强度和延伸率.升高温度或延长保温时间,合金的脆性断裂倾向减小,拉伸断口呈现出较多的韧窝,对大幅度提高合金的力学性能极为有利.The partial solid-solution treatment was carried out for the AZ91 Dmagnesium alloy and its microstructure and mechanical properties were investigated.The result showed that at lower temperature,the change of mechanical properties of the alloys with time was not apparent.At risen temperature,its hardness would reduce gradually with time but its tensile strength and elongation rate increase gradually with time.When the heat-retaining time maintained constant,the hardness would gradually decrease with temperature and the tensile strength and elongation rate would increase gradually with temperature.After partial solid-solution treatment,part of the hard and brittle phaseβ-Mg17Al12 at grain boundary would dissolve into the matrix and distribute in the shape of islands instead of original reticula.Due to the partial reduction of the hard-brittle phase,the hardness of the alloy would decrease to a certain extent but it was still higher than that of the alloy after complete solid-solution treatment.The tensile strength and elongation rate of the alloys were improved owing to the change of the morphology of the hard-brittle phase.When the temperature was rose or heat-retaining time prolonged,the tendency of brittle-fracturing of the alloy would reduce,and more tough dimples appeared in the tensile fracture,which would be extremely beneficial to improve the mechanical properties of the alloy to a great extent.

关 键 词：AZ91D镁合金 β-Mg17Al12相 部分固溶处理 力学性能 

分 类 号：TG146[一般工业技术—材料科学与工程]