半固態(tài)漿料的影響(Ⅰ)
(1. 蘭州理工大學(xué) 甘肅省有色金屬新材料省部共建國家重點(diǎn)實(shí)驗(yàn)室，蘭州 730050；
2. 蘭州理工大學(xué) 有色金屬合金及加工教育部重點(diǎn)實(shí)驗(yàn)室，蘭州 730050)
摘 要: 采用新型的自孕育法制備AM60鎂合金半固態(tài)漿料，研究澆注溫度對自孕育法制備AM60鎂合金半固態(tài)漿料的影響。結(jié)果表明：隨著澆注溫度的降低，組織中發(fā)達(dá)和粗大的樹枝晶逐漸減少；在接近液相線溫度時出現(xiàn)小塊狀或薔薇狀晶粒，晶粒的尺寸逐漸減小；分布逐漸趨向正態(tài)分布，且存在一個合適的溫度加工區(qū)間，即630 ~ 680 ℃，對應(yīng)的晶粒尺寸為58.4~63.1 μm。加入的孕育劑在熔體中起到內(nèi)冷鐵作用，加快熔體的冷卻速率，使熔體快速到達(dá)半固態(tài)區(qū)間。采用自孕育法制漿時，合金熔體中晶核主要來源于熔體中的高熔點(diǎn)質(zhì)點(diǎn)(Al8Mn5)、孕育形核和晶粒游離與增殖。
關(guān)鍵字: 鎂合金；AM60鎂合金；半固態(tài)漿料；自孕育法；澆注溫度；凝固過程
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
