脉冲Nd:YAG激光熔覆修复塑料模具工艺参数的优化

 激光器的电压、电流、脉冲宽度、脉冲频率与激光的扫描速度、光斑直径等工艺参数直接影响着脉冲Nd:YAG激光熔覆质量。为了简化工艺调整过程，提出了重叠率的概念，并进行了理论推导，建立了重叠率与脉冲频率、激光扫描速度、激光光斑直径相互关系的方程式。利用预置法在低碳钢基体上熔覆Ni基合金粉末,获得了2组最佳工艺参数，即单脉冲能量、重叠率分别为6.7 J,97.4%和21 J,69.4%。研究表明：在单脉冲能量和重叠率一定的条件下，改变电流、脉宽、脉冲频率及熔覆速度不会影响熔覆质量。

Processing parameters optimization of pulsed Nd:YAG laser cladding repairing plastic moulds

The quality of pulsed Nd:YAG laser cladding depends on the voltage,electric current,pulse length,pulse frequency,scanning speed,and beam diameter of the Nd:YAG laser.In order to fully conside the effect of these processing parameters and simplify the processes,spot overlap definition is referred.With the help of theoretic analysis,the relationship between spot overlap and three parameters(the pulse frequency,the scanning speed and the beam diameter of the Nd:YAG laser) is formulated.The experiment,which is based on lower carbon steel,is carried out with precoated layer by laser cladding Ni-base alloy.The perfect processing parameters are available,with single pulsed energy and spot overlap separately 6.7 J and 97.4% or 21 J and 69.4%.