半固态浆料的影响(Ⅰ)
(1. 兰州理工大学 甘肃省有色金属新材料省部共建国家重点实验室，兰州 730050；
2. 兰州理工大学 有色金属合金及加工教育部重点实验室，兰州 730050)
摘 要: 采用新型的自孕育法制备AM60镁合金半固态浆料，研究浇注温度对自孕育法制备AM60镁合金半固态浆料的影响。结果表明：随着浇注温度的降低，组织中发达和粗大的树枝晶逐渐减少；在接近液相线温度时出现小块状或蔷薇状晶粒，晶粒的尺寸逐渐减小；分布逐渐趋向正态分布，且存在一个合适的温度加工区间，即630 ~ 680 ℃，对应的晶粒尺寸为58.4~63.1 μm。加入的孕育剂在熔体中起到内冷铁作用，加快熔体的冷却速率，使熔体快速到达半固态区间。采用自孕育法制浆时，合金熔体中晶核主要来源于熔体中的高熔点质点(Al8Mn5)、孕育形核和晶粒游离与增殖。
关键字: 镁合金；AM60镁合金；半固态浆料；自孕育法；浇注温度；凝固过程
prepared by self-inoculation method (Ⅰ)
（1. State Key Laboratory of Gansu Advanced Non-ferrous Metal Materials,
Lanzhou University of Technology, Lanzhou 730050, China;
2. Key Laboratory of Non-ferrous Metal Alloys and Processing, Ministry of Education,
Lanzhou University of Technology, Lanzhou 730050, China）
Abstract:The semi-solid slurry of AM60 Mg alloy was prepared by a novel self-inoculation method(SIM). The effect of pouring temperature on the semi-solid slurry prepared by self-inoculation method was investigated. The results show that the coarser dendrite reduces with the decrease of pouring temperature. A small block or rosette grain is obtained when the pouring temperature is near-liquidus. Meanwhile, the grain size also decreases, and it becomes approximately normally distributed. An ideal temperature process interval/window has to be required between 630 ℃ and 680 ℃, and the grain size is 58.4−63.1 μm correspondingly. The added inoculants are as internal chill in AM60 melt, which accelerates the cooling rate of the melt, as a result, the melt is cooled down to semi-solid range rapidly. The nuclei are from high melting point phases in the melt (such as Al8Mn5), inoculants, and the grain of the free and the proliferation.
Key words: Mg alloy; AM60 Mg alloy; semi-solid state slurry; self-inoculation method; pouring temperature
