【摘要】 采用精密的侧吹辅助气体调节和控制装置，实验研究了等离子体控制的各种工艺参数；采用光电晶体管检测熔池表面及小孔内等离子体光强变化；从理论上分析了等离子体控制的机理．结果表明：当辅助气体流量变化时，等离子体控制效果呈现三个区间．无论采用何种气体，只要辅助气体的操作压力稍大于金属蒸气压力，等离子体即被最佳控制更多还原

【Abstract】 A series of technological parameters in controlling plasma in high power CO 2 laser welding were investigated by using a precise declined blow system for assist gas regulating and controlling. The plasma light intensity above molten pool and in key hole was also measured by phototransisters. The plasma control mechanism was theoretically analysed. The results show that plasma control effect was divided into three regions with the change of assist gas flow quantity. No matter what gas species were used, plasma can be best controlled only was the assist gas operation pressure slightly higher than the metallic vapour pressure.更多还原