(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實驗室，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實驗室，蘭州 730050)
摘 要: 采用自孕育法制備新型Mg-9Zn-2Al高鋅鎂合金半固態(tài)漿料，研究孕育劑加入量為5%(質(zhì)量分數(shù))、導(dǎo)流器角度為45°時熔體處理溫度對Mg-9Zn-2Al鎂合金組織的影響。對孕育劑加入熔體后的熔化狀況進行分析，并從原子團簇角度探討熔體處理溫度對一次孕育的作用機理。結(jié)果表明：熔體處理溫度過高或過低時，組織平均晶粒尺寸較大；在695~710 ℃范圍內(nèi)，晶粒平均尺寸較小，約為47.5~48.8 μm。根據(jù)所推導(dǎo)出的孕育劑在導(dǎo)流器入口處的溫度表達式，可以確定自孕育法鑄造的最佳熔體處理溫度，提出用固相率fS描述自孕育劑的熔化狀況。
關(guān)鍵字: Mg-9Zn-2Al鎂合金；半固態(tài)漿料；熔體處理；自孕育法；原子團簇
（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:A noval high zinc-content Mg-9Zn-2Al magnesium alloy semi-solid slurry was prepared by self-inoculation method(SIM). The effect of melt treatment temperature on the microstructure was investigated when the addition of self-inoculants is 5% (mass fraction) and the angle of fluid director is 45°. The melting state of the inoculants was analyzed. Furthermore, the mechanism of the primary inoculation was discussed from the standpoint of atomic cluster. The results show that the average grain size increases when the melt temperature is excessively low or high. In temperature range of 695−710 ℃, the average grain size is smaller, about 47.5−48.8 μm. In SIM casting, a proper melt treatment temperature can be determined by the derived formula, which is the temperature of the inoculants in the entrance of fluid director. Meanwhile, the solid phase ratio fS is put forward to describe the case of inoculants’ melting.
Key words: Mg-9Zn-2Al magnesium alloy; semi-solid slurry; melt treatment; self-inoculation method (SIM); atomic cluster
