Su Yishun, Wang Liang, Yao Zhehe, Zhang Qunli, Chen Zhijun, Duan Jiawei, Ye Tingqing, Yao Jianhua
College of Mechanical Engineering, Zhejiang University of Technology, Hangzhou 310023, China.
Automobile School, Zhejiang Institute of Communications, Hangzhou 311112, China.
Materials (Basel). 2025 Aug 1;18(15):3626. doi: 10.3390/ma18153626.
Carbon deposits on the crown of engine pistons can markedly reduce combustion efficiency and shorten service life. Conventional cleaning techniques often fail to simultaneously ensure a high carbon removal efficiency and maintain optimal surface integrity. To enable efficient and precise carbon removal, this study proposes the application of hybrid laser cleaning-combining continuous-wave (CW) and pulsed lasers-to piston carbon deposit removal, and employs response surface methodology (RSM) for multi-objective process optimization. Using the N52B30 engine piston as the experimental substrate, this study systematically investigates the combined effects of key process parameters-including CW laser power, pulsed laser power, cleaning speed, and pulse repetition frequency-on surface roughness (Sa) and carbon residue rate (RC). Plackett-Burman design was employed to identify significant factors, the method of the steepest ascent was utilized to approximate the optimal region, and a quadratic regression model was constructed using Box-Behnken response surface methodology. The results reveal that the Y-direction cleaning speed and pulsed laser power exert the most pronounced influence on surface roughness (F-values of 112.58 and 34.85, respectively), whereas CW laser power has the strongest effect on the carbon residue rate (F-value of 57.74). The optimized process parameters are as follows: CW laser power set at 625.8 W, pulsed laser power at 250.08 W, Y-direction cleaning speed of 15.00 mm/s, and pulse repetition frequency of 31.54 kHz. Under these conditions, the surface roughness (Sa) is reduced to 0.947 μm, and the carbon residue rate (RC) is lowered to 3.67%, thereby satisfying the service performance requirements for engine pistons. This study offers technical insights into the precise control of the hybrid laser cleaning process and its practical application in engine maintenance and the remanufacturing of end-of-life components.
发动机活塞顶部的积碳会显著降低燃烧效率并缩短使用寿命。传统的清洁技术往往无法同时确保高除碳效率和维持最佳的表面完整性。为实现高效、精确的除碳，本研究提出将连续波（CW）激光和脉冲激光相结合的混合激光清洗技术应用于活塞积碳清除，并采用响应面法（RSM）进行多目标工艺优化。以N52B30发动机活塞作为实验基材，本研究系统地探究了关键工艺参数（包括连续波激光功率、脉冲激光功率、清洗速度和脉冲重复频率）对表面粗糙度（Sa）和残碳率（RC）的综合影响。采用Plackett-Burman设计来识别显著因素，利用最速上升法逼近最优区域，并使用Box-Behnken响应面法构建二次回归模型。结果表明，Y向清洗速度和脉冲激光功率对表面粗糙度影响最为显著（F值分别为112.58和34.85），而连续波激光功率对残碳率影响最大（F值为57.74）。优化后的工艺参数如下：连续波激光功率设定为625.8 W，脉冲激光功率为250.08 W，Y向清洗速度为15.00 mm/s，脉冲重复频率为31.54 kHz。在此条件下，表面粗糙度（Sa）降至0.947μm，残碳率（RC）降至3.67%，从而满足发动机活塞的使用性能要求。本研究为混合激光清洗工艺的精确控制及其在发动机维护和报废零部件再制造中的实际应用提供了技术见解。
