变质和热处理对汽车用Al-Si合金组织与性能的影响  

Effects of modification and heat treatment on microstructure and mechanical properties of Al-Si alloy

作　　者：赵二丽[1,2] 徐志成[2] 

机构地区：[1]浙江工业职业技术学院,浙江绍兴312000 [2]浙江大学材料科学与工程学院,浙江杭州311509

出　　处：《金属热处理》2016年第6期138-142,共5页Heat Treatment of Metals

摘　　要：以Al-5Ti-B和Al-10RE为变质剂对汽车用Al-Si合金进行了复合变质处理,研究了Al-10RE含量和热处理对Al-Si合金组织与力学性能的影响。结果表明:Al-10RE含量为0.6%时,Al-Si合金中的针状共晶硅转变为短棒状、α-Al枝晶得到了较好细化;AlSi合金的硬度、抗拉强度和断后伸长率随着Al-10RE含量的增加呈现先增加后降低的趋势,在Al-10RE含量为0.6%时取得最大值;T6热处理使合金中共晶硅的形态从杆状转变为类球形,复合变质处理的Al-Si合金在T6热处理工艺下可以获得更加细小、均匀的共晶硅相;T6热处理后,未变质处理和复合变质处理的Al-Si合金的抗拉强度都较铸态合金有所提高,而断后伸长率略有降低。Effect of AI-10RE content and heat treatment on microstructure and mechanical properties of AI-Si alloy were studied by using A1- 10RE and A1-STi-B as the modifier. The results show that, when the AI-10RE content is 0.6%, the acicular eutectic Si phase in A1-Si alloy is transformed to short rod, and ct-A1 dendrite is well refined. The hardness, tensile strength and elongation of A1-Si alloy increase at first and then decrease with the increasing of AI-10RE content, the maximum values are obtained at AI-10RE content of 0.6%. The eutectic silicon in the A1-Si alloy change from rod into spherical after T6 heat treatment, the composite modified of A1-Si alloy in the T6 heat treatment process can obtain a more fine and uniform eutectic silicon phase; after T6 heat treatment, the tensile strength without modification and with composite modified A1-Si alloy are all higher than that of as-cast alloy, while elongation decrease slightly.

关 键 词：复合变质 T6热处理 AL-SI合金 组织 力学性能 

分 类 号：TG156[金属学及工艺—热处理]