冷却速率对Al-Cu二元合金凝固组织和性能的影响  

Effect of Cooling Rate on Solidification Microstructure and Properties of Al-Cu Binary Alloy

作　　者：王向杰 杨凌飞[1,2] 谭宏娟 于芳 崔建忠 Wang Xiangjie;Yang Lingfei;Tan Hongjuan;Yu Fang;Cui Jianzhong(Key Lab of Electromagnetic Processing of Materials,Ministry of Education,Northeastern University,Shenyang 110819,China;Advanced Manufacturing Technology and Engineering Research Centers,Northeastern University,Shenyang 110819,China)

机构地区：[1]东北大学材料电磁过程研究教育部重点实验室,辽宁沈阳110819 [2]东北大学材料先进制备技术教育部工程研究中心,辽宁沈阳110819

出　　处：《稀有金属材料与工程》2022年第6期2033-2038,共6页Rare Metal Materials and Engineering

基　　金：Fundamental Research Funds for the National Natural Science Foundation of China(U1708251);Key Research and Development Program of Liaoning(2020JH2/10700003);Liaoning Revitalization Talents Program,China(XLYC1807027);Fundamental Research Funds for the Central Universities(N2109004)。

摘　　要：为了研究冷却速率对Al-Cu二元合金凝固组织和性能的影响,通过楔形铜模铸造制备了Al-6%Cu合金铸锭。结果表明,当冷却速率从100 K/s降低到2 K/s时,铸锭晶粒形态的转变过程为:全部柱状晶→柱状晶与等轴晶混合→全部等轴晶。同时,靠近模壁处的柱状晶宽度从244.7μm增加到408.2μm,铸锭心部等轴晶的平均晶粒尺寸从629.8μm减小到152.8μm,并且平均枝晶臂间距从10.1μm增加到52.8μm。计算得出Al-6%Cu合金平均枝晶臂间距和冷却速率经验公式中的参数,其中A和n的值分别为78.75和0.41。当冷却速率从100 K/s降低到25 K/s时,共晶Al_(2)Cu的形态从骨骼状变为片层状,在共晶Al_(2)Cu附近的α-Al的形态呈蜂窝状。当冷却速率由2 K/s增加到100 K/s时,Al-6%Cu合金的硬度由618 MPa增加到726 MPa。To investigate the influence of cooling rate on the solidification structure of Al-Cu binary alloy,the ingot of Al-6%Cu alloy was produced by the wedge-shaped copper mode casting.The results indicate that when the cooling rate decreases from 100 K/s to 2 K/s,the grain morphology transformation of ingot is as follows:columnar grains→mixing of columnar grains with equiaxed grains→equiaxed grains.Meanwhile,the width of columnar crystal at the ingot edge increases from 244.7μm to 408.2μm,the average grain size of equiaxed crystal at the ingot core decreases from 629.8μm to 152.8μm,and the average dendrite arm spacing increases from 10.1μm to 52.8μm.The parameters A and n of Al-6%Cu alloy in the empirical formula of average dendrite arm spacing and cooling rate are 78.75 and 0.41,respectively.When the cooling rate decreases from 100 K/s to 25 K/s,the morphology of eutectic Al_(2)Cu changes from skeletal to lamellar,and α-Al near the eutectic Al_(2)Cu is cellular.With the cooling rate increases from 2 K/s to 100 K/s,the hardness of Al-6%Cu alloy is increased from 618 MPa to 726 MPa.

关 键 词：Al-Cu二元合金 楔形铜模铸造 凝固组织 冷却速率 性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程]