Cu-Mn合金的激光表面快速熔凝

为对 Cu- 2 7.3% Mn合金在超高温度梯度快速定向凝固条件下的组织形成规律和胞晶间距进行研究 ,利用5 k W CW CO2 激光器进行了一系列激光表面重熔实验。实验结果表明 :在快速凝固条件下 ,随着凝固速度的提高 ,Cu- 2 7.3% Mn的组织由低速平界面向胞晶、超细胞晶和不规则组织转变 ;当凝固速度达到 2 12 .6 mm /s时 ,生长达到绝对稳定 ;在所有凝固速度范围内无枝晶组织出现。在激光表面快速熔凝过程中 ,从熔池底部到顶部胞晶间距略有减小 ,且间距的选择具有历史相关性。

Laser rapid surface remelting of Cu-Mn alloy

Detailed laser surface remelting experiments of Cu- 27.3% Mn alloy on a 5 kW CW CO 2 laser were used to investigate microstructure evolution and cellular spacing selection with growth rate for ultra-high temperature gradient and rapid directional solidification. The experimental results show that the microstructure of Cu-27.3%Mn alloy changes from cellular to super-fine cellular, irregular microstructure and segregation-free solid with increasing growth rate with dendrite growth over the whole growth rate range, so the structure is fully cellular. The critical rate for absolute stability for the 27.3%Mn alloy is 212.6 mm/s . From bottom to top in the molten pool, the average spacing decreases with increasing growth rate and is history-dependent.