(廣東工業(yè)大學(xué) 材料與能源學(xué)院，廣州 510006)
摘 要: 采用機械攪拌半固態(tài)鑄造技術(shù)制備Sn-62Bi合金，通過XRD、EDS等測試方法探索了不同固相率下剪切力和作用時間對半固態(tài)Sn-Bi合金組織和塑性的影響。結(jié)果表明：在半固態(tài)溫度145 ℃、攪拌速度為500 r/min和攪拌時間為15 min的工藝條件下，制備出分布均勻、尺寸約30 μm塊狀鉍初生相的半固態(tài)Sn-62Bi合金，拉伸試驗下的伸長率為39.9%，與在180 ℃下的合金金屬熔液直接水冷凝固而成的試樣相比，其伸長率提高了283.3%。當(dāng)攪拌溫度為150 ℃時，隨著攪拌時間的延長，塊狀初生相Bi相相互摩擦和碰撞破碎，初生相的尺寸減少，分布較均勻，所制備的半固態(tài)Sn-62Bi合金的伸長率得到改善。
關(guān)鍵字: 半固態(tài)錫鉍合金；機械攪拌；組織演變；塑性
（School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006, China）
Abstract:The hypereutectic Sn-62Bi alloy was obtained by semi-solid mechanical stirring casting technology. The influences of shear force and stirring time on the microstructure and plasticity of semi-solid alloy under different solid phase ratios were investigated. The results show that the semi-solid Sn-62Bi alloy with uniform distribution and fine quadrate primary Bi phase is obtained at agitating rate of 500 r/min, the temperature of 145 ℃ and the stirring time of 15 min. The size of quadrate primary Bi phase is about 30 μm. The elongation of semi-solid Sn-Bi alloy prepared is 39.9%, which is improved by 283.3%, compared to that of Sn-62Bi alloy prepared from the molten alloy at 180 ℃ and solidified in water. When the agitating temperature is 150 ℃, the friction and collision of quadrate primary Bi phase particles increase with increasing the stirring time, the probability of the friction and collision between quadrate primary Bi phase particle increases with increasing the stirring time, which leads to that the particles sizes become smaller and the particles distributions are uniform, and the elongation is improved.
Key words: semi-solid Sn-Bi alloy; mechanical stirring; microstructure evolution; plasticity
