(1. 西南交通大學(xué) 材料科學(xué)與工程學(xué)院，成都 610031；
2. 華中科技大學(xué) 材料成形與模具技術(shù)國(guó)家重點(diǎn)實(shí)驗(yàn)室，武漢 430074)
摘 要: 將采用超聲振動(dòng)制備的過(guò)共晶Al-Si合金A390漿料在不同溫度下進(jìn)行流變壓鑄成形，研究漿料澆注溫度對(duì)過(guò)共晶Al-Si合金流變壓鑄試樣組織和力學(xué)性能的影響。結(jié)果表明：過(guò)共晶Al-Si合金A390流變壓鑄試樣組織中初生Si主要由漿料制備過(guò)程中形成的大塊Si(Si1)和在壓鑄模型腔中形成的細(xì)小Si(Si3)組成；在580~640 ℃范圍內(nèi)，隨著漿料澆注溫度升高，Si1平均尺寸先減小后增大，而Si3尺寸穩(wěn)定在7~15 μm之間。過(guò)共晶Al-Si合金A390半固態(tài)漿料的適宜澆注溫度范圍為600~620 ℃，在此范圍內(nèi)可以得到抗拉強(qiáng)度超過(guò)260 MPa的A390合金流變壓鑄試樣。
關(guān)鍵字: Al-Si合金；半固態(tài)漿料；流變壓鑄；過(guò)共晶；力學(xué)性能
（1. School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China;
2. State Key Laboratory of Materials Processing and Die & Mould Technology,
Huazhong University of Science and Technology, Wuhan 430074, China）
Abstract:The hypereutectic Al-Si alloy A390 slurry was prepared by ultrasonic vibration and rheo-diecasted at different temperatures, and the effect of slurry pouring temperature on the microstructure and mechanical properties of hypereutectic Al-Si alloy rheo-diecasting sample was investigated. The results show that, the primary Si in the microstructure of rheo-diecasting sample of A390 alloy is mainly composed of large Si (Si1) formed during slurry preparation process and small Si (Si3) formed in die cavity; with the slurry pouring temperature increasing from 580 to 640 ℃, the average size of Si1 first decreases and then increases while that of Si3 maintains in the range of 7−15 μm. It is also found that the slurry pouring temperature suitable for rheo-diecasting of hypereutectic Al-Si alloy A390 semi-solid slurry is 600−620 ℃, and in this range the tensile strength of rheo-diecasting sample is up to more than 260 MPa.
Key words: Al-Si alloy; semisolid slurry; rheo-diecasting; hypereutectic; mechanical properties
