Effect of nano TiN/Ti refiner on as-cast and hot-working microstructure of commercial purity aluminum  

纳米TiN/Ti复合细化剂对工业纯铝铸态及热加工态组织的影响(英文)

作　　者：蔡思祺[1] 李玉洁[2] 谌援[2] 李欣蔚[2] 薛丽红[2] 

机构地区：[1]华中科技大学机械科学与工程学院,武汉430074 [2]华中科技大学材料科学与工程学院,武汉430074

出　　处：《Transactions of Nonferrous Metals Society of China》2013年第7期1890-1897,共8页中国有色金属学报（英文版）

摘　　要：A novel type nano TiN/Ti composite grain refiner （TiN/Ti refiner） was prepared by high energy ball milling, and its effect on as-cast and hot-working microstructure of commercial purity aluminum （pure Al） was investigated. The results show that TiN/Ti refiner exhibits excellent grain refining performances on pure Al. With an addition of 0.2% TiN/Ti refiner, the average grain size of pure Al decreases to 82 μm, which is smaller than that of pure Ti and Al 5Ti 1B master alloy as refiners. The microstructure of weld joint of pure Al with 0.1% TiN/Ti refiner is fine equiaxed grains and the hardness of weld joint is higher than that of the base metal. For pure Al with 40% cold deformation and recrystallization at 250 °C for 1.0 h, the grains of the sample added 0.1% Ti powder have an obvious grain growth behavior. In contrast, oriented grains caused by deformation have been eliminated, and there is no obvious grain growth in pure Al refined with 0.1% TiN/Ti refiner, indicating that nano TiN in the refiner inhibits the growth of grain during recrystallization.采用高能球磨法制备一种纳米TiN/Ti复合晶粒细化剂,研究该细化剂对工业纯铝的铸态及热加工态组织的影响。结果表明:TiN/Ti复合细化剂对工业纯铝具有明显的晶粒细化作用,当TiN/Ti复合细化剂添加量为0.2%时(质量分数),平均晶粒尺寸细化至82μm,其细化效果优于纯Ti和Al5Ti1B中间合金。添加0.1%TiN/Ti纯铝铸锭的焊缝组织以细小的等轴晶为主,焊缝硬度明显高于母材。冷变形量为40%的纯铝铸锭于250°C下再结晶处理1.0h后,添加0.1%Ti粉的试样晶粒长大较为明显。而添加0.1%TiN/Ti的试样,因变形导致的晶粒变形已消除,晶粒没有明显增粗,表明细化剂中的纳米TiN可抑制再结晶过程中的晶粒长大。

关 键 词：nano TiN/Ti composite grain refiner commercial purity aluminum grain refinement weld joint deformation and recrystallization 

分 类 号：TG146.21[一般工业技术—材料科学与工程]