内燃机缸套-活塞环摩擦副激光表面微造型模拟与试验研究

Simulation and Experiment Study on Laser Surface Micro-texturing on Cylinder Liner-Piston Ring Friction Pair of Internal Combustion Engine

以内燃机缸套-活塞环摩擦副系统为对象,对单脉冲同点间隔多次激光微造型的热作用过程进行数值模拟和试验研究,获得了激光脉冲次数和激光功率对45#钢靶材表面微凹腔形貌的影响规律。仿真和试验结果表明:随着激光脉冲次数的增加,微凹腔深度不断增加,金属熔液的重铸现象明显,表面加工质量下降;随激光功率的增加,微凹腔的深度增加幅度不大且趋于平缓,微凹腔外沿金属残渣增多,加工质量下降,光斑中心温度近似线性增加;在相同工况条件下,微凹腔的深度仿真结果与试验结果趋势基本一致,最大误差在8%以内,证明了该数值模拟方法的可行性和有效性。

Numerical simulation and experimental study on cylinder liner and piston rings friction system were carried out in order to study the thermal mechanism of laser surface texturing with multi-time single-pulse laser at the same point. The variation of the surface micro-texture of 45 carbon steel was analyzed under the condition of changing laser power and number of laser pulses. The simulation and experimental results show that micro-cavity depth increases, metal liquid recasting gets obvious and surface machining quality gets worse with the increase in the number of laser pulses. When the laser power increases, micro-cavity depth does not increase greatly and the depth change tends to a little; meanwhile because of metal liquid recasting on the outer of micro-cavity surface, machining quality gets worse and the temperature of laser spot center increases approximately in linear. The simulation results of the depth of micro cavity are close to those of experiments with the maximum error within 8 % under the same condition, which proves the feasibility and effectiveness of this numerical simulation method.