摘要
以铜块、镍板和锡锭为原料,分别采用方形铁模熔铸、圆柱形水冷铜模铸造和双辊薄带铸轧工艺制备Cu-9Ni-6Sn铸造合金,对应的冷却速率分别为2.3,18.7,138.6℃·s^(-1);采用高温激光共聚焦显微镜观察了铸造合金在凝固过程中的组织演变,结合铸态合金组织分析,研究了冷却速率对组织和元素偏析行为的影响。结果表明:该合金的凝固过程经历L→L+α→α+(α+γ)+γ的相变。凝固过程中组织逐渐呈树枝晶形貌,枝晶干为贫锡α相,枝晶间为富锡γ相,枝晶干与枝晶间的过渡区域形成层片状α+γ相。随着冷却速率提高,合金凝固过程中形成的树枝晶尺寸减小,铸态组织由粗大树枝晶转变为等轴晶,铸态组织发生细化,同时锡元素的周期性偏析得到抑制。
With copper blocks,nickel plates,and tin ingots as raw materials,Cu-9Ni-6Sn cast alloys were prepared by square iron mold casting,cylindrical water-cooled copper mold casting,and twin-roll strip casting processes,with corresponding cooling rates of 2.3,18.7,and 138.6℃·s^(−1),respectively.The microstructural evolution during solidification was observed by high-temperature laser confocal microscopy,and the influence of cooling rate on the microstructure and elemental segregation behavior was investigated combined with the analysis of the as-cast microstructure.The results show that the solidification process of the alloy underwent the phase transformation sequence L→L+α→α+(α+γ)+γ.During solidification,the microstructure developed a dendritic morphology,with the dendritic trunks being Sn-poor α phase and the interdendritic regions being Sn-richγphase,while the transitional zone between trunks and interdendritic areas formed a lamellar α+γ phase.With the increase of cooling rate,the dendritic size during solidification of the alloy decreased,and the as-cast microstructure transformed from coarse dendrites to equiaxed grains,resulting in microstructural refinement,and the periodic segregation of Sn was simultaneously suppressed.
作者
李会玲
陈晨
魏亚风
贾飞
LI Huiling;CHEN Chen;WEI Yafeng;JIA Fei(School of Intelligent Manufacturing,Dongguan Polytechnic,Dongguan 523808,China;State Key Laboratory of Rolling and Automation,Northeastern University,Shenyang 110200,China)
出处
《机械工程材料》
北大核心
2026年第2期80-86,共7页
Materials For Mechanical Engineering
