Rapid Directional Solidification with Ultra-High Temperature Gradient and Cellular Spacing Selection of Cu-Mn Alloy

The detailed laser surface remelting experiments of Cu-31.4 Wt pct Mn and Cu-26.6 wt pct Mn alloys on a 5 kW CO;Iaser were carried out to Study the effects of processing parameters （scanning velocity, output power of laser） on the growthdirection of microstructure in the molten pool and cellular spacing selection under the condition of ultra-high temperaturegradient and rapid directional solidification. The experimental results show that the growth direction of microstructure isstrongly affected by laser processing parameters. The ultra-high temperature gradient directional solidification can be realizedon the Surface of samples during laser surface remelting by controlling laser processing parameters, the temperature gradientand growth velocity can reach 10;K/m and 24.1 mm/s, respectively, and the solidification microstructure in the center ofthe molten pool grows along the laser beam scanning direction. There exists a distribution range of cellular spacings underthe laser rapid solidification condi