激光快速凝固条件下Cu-31.4%Mn合金的微观组织特征  

Microstructure characteristics of Cu-31.4%Mn alloy under laser rapid solidification condition

作　　者：杨森[1] 苏云鹏[2] 刘文今[1] 黄卫东[2] 周尧和[2] 

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

出　　处：《物理学报》2003年第1期81-86,共6页Acta Physica Sinica

基　　金：国家自然科学基金 (批准号 :5 97710 5 4);中国博士后科学基金;清华中大博士后科学基金;清华大学 985基金资助的课题~~

摘　　要：利用连续波CO2 激光器对Cu 31 4 %Mn进行了系列表面熔凝实验 ,对该合金的组织形态和胞晶间距选择规律进行了研究 .结果表明 :随着生长速度的提高 ,组织形态由低速平界面向展宽胞晶、规则胞晶、展宽胞晶、类平面晶和高速绝对稳定平界面转变 .在快速凝固条件下 ,Cu 31 4 %Mn合金的胞晶间距存在一个选择范围 ,最大、最小和平均胞晶间距与生长速度的关系分别为λmax=6 82v- 0 33s ,λmin=2 89v- 0 2 8s 和 λ =4 35v- 0 31s ,实验结果与Hunt Lu模型的预测结果相吻合 .Laser rapid solidification experiments have been performed on Cu-31.4% Mn alloy to investigate the response of microstructure pattern and cellular spacing selection to the variation of growth rate. With increasing growth rate, microstructures go from light band to elongated cell, regular cell, then elongated cell and planar-like structure, and finally to absolute stability planar in turn. Experimental results show that there is a distribution range in cellular spacing under the laser rapid solidification condition, the distribution range and the average spacing decrease with the increase of the growth rate. The maximum, lambda(max), minimum, lambda(min), and average primary spacing, lambda, as functions of growth rate v(s), can be given by lambda(max)=6. 82 v(s)(-0.33), lambda(min)=2.89v(s)(-0.28) and lambda=4.35v(s)(-0.31), respectively. The experimental results are compared with the Hunt-Lu numerical model for rapid cellular/dendritic growth,and a reasonable agreement is found.

关 键 词：激光快速凝固 微观组织 激光表面熔凝 胞晶间距 Cu-Mn合金 绝对稳定性 铜锰合金 组织形态 

分 类 号：TG13[一般工业技术—材料科学与工程]