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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。
In order to study the formation regularity and cell spacing of Cu-2 7.3% Mn alloy under the condition of ultra-high temperature gradient rapid solidification, a series of laser surface remelting experiments were carried out using a 5 kW CW CO2 laser. The experimental results show that the microstructure of Cu-2 7.3% Mn changes from low-velocity flat boundary to cellular, supercrystalline and irregular microstructure under the condition of rapid solidification. When the solidification rate reaches 2 12.6 mm / s, the growth reaches absolute stability; no dendritic microstructure appears in all solidification rates. In the rapid laser surface melting process, from the bottom of the pool to the top of the cell spacing slightly decreased, and the choice of spacing has a historical correlation.