激光超高温度梯度快速凝固条件下CuMn合金的组织演化规律  

Microstructure evolution of Cu Mn alloy under laser ultra high temperature gradient and rapid solidification condition

作　　者：杨森[1] 钟敏霖[1] 张庆茂[1] 黄卫东[2] 刘文今[1] 周尧和[2] 

机构地区：[1]清华大学机械系,北京100084 [2]西北工业大学凝固技术国家重点实验室,陕西西安710072

出　　处：《航空材料学报》2001年第2期1-5,13,共6页Journal of Aeronautical Materials

基　　金：国家自然科学基金 (5 97710 5 4) ;清华大学 985重点资助项目

摘　　要：利用CWCO2 激光器对Cu 2 6 .6wt%Mn ,Cu 2 7.3wt%Mn和Cu 31.4wt %Mn三种不同成分的合金进行了一系列表面熔凝实验 ,并对这三种合金的组织形态选择规律进行了研究。实验结果表明 ,重熔区组织较基体组织大大细化 ;随着生长速度的增大 ,Cu 2 6 .6wt %Mn合金的组织由低速胞晶向枝晶、高速胞晶及完全无偏析固溶体转变。在所有凝固速度下Cu 2 7.3wt%Mn和Cu 31.4wt%Mn合金中没有枝晶组织出现 ,以全胞晶形式生长。三种合金达到绝对稳定的临界速度分别为 113 .3 ,2 12 .6和 2 6 0 .5mm/s ,与MLaser rapid solidification experiments have been performed on Cu-26.6wt% Mn, Cu-27.3wt% Mn and Cu-31.4wt% Mn alloys to investigate their microstructures evolution with growth rate under ultra-high temperature gradient, respectively. The experimental results showed that the microstructure of Cu-26.6wt% Mn alloy changed from cellular to dendrite, super-fine cellular and segregation-free solid with the increase of growth rate; no dendrite growth appeared in the whole growth rate range for Cu-27.3wt% Mn and Cu-31.4wt% Mn alloy, whereas fully grew in the form of cellular. The critical rates of absolute stability for Cu-31.4wt%Mn, Cu-27.3wt%Mn and Cu-26.6wt% Mn alloys were 113.3, 212.6 and 260.5mm/s, respectively, which is reasonable agreement with that of the predicted By M-S theory.

关 键 词：表面熔凝实验 组织形态 选择规律 重熔区 基体组织 细化 连续二氧化碳激光器 激光快速凝固 绝对稳定性 超高温梯度 Cu-Mn铜锰合金 全胞晶 枝晶 M-S理论 组织演化规律 

分 类 号：TG146.11[一般工业技术—材料科学与工程] TN249[金属学及工艺—金属材料]