Zhang Wei, Wang Chunming, Wu Qiong, Yan Fei, Zhu Guoli, Wang Junqiang
School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
Materials (Basel). 2025 Mar 12;18(6):1247. doi: 10.3390/ma18061247.
Laser cleaning has received extensive attention due to its high efficiency, non-pollution and easy automation. However, how to improve the cleaning quality has become the focus of current research. In this paper, we used a pulsed laser for cleaning experiments on Q235B carbon steel to investigate the effects of different process parameters on the surface cleaning quality. On this basis, a new cleaning method was innovatively proposed to improve the oxide removal efficiency, microstructure, and mechanical properties of cleaned samples. The results showed that pulsed laser cleaning of Q235B carbon steel was the most effective at a laser linewidth of 50 mm, pulsed frequency of 500 kHz, and cleaning speed of 15 mm/s. A great deal of craters formed on the surface of cleaned samples due to the thermal shock of the pulsed laser. Compared with other laser cleaning methods, integrated laser cleaning had an obvious effect in raising the oxide removal efficiency and reducing the surface roughness. The ridge structures on the sample surface also could be successfully eliminated, subsequently achieving smooth structures. Fine-crystalline structures were formed near the surface of tested samples, which significantly decreased the crystal orientation and increased the number of small angle grain boundaries and the GND density. The improvement in hardness was mainly on account of grain refinement in the integrated laser cleaning samples. In addition, a physical model was proposed to illustrate the oxide removal mechanism on integrated pulsed-continuous laser cleaning samples. This research can offer new theoretical and technical support for solving the long-standing problems of efficiency and quality in laser cleaning, thus significantly broadening the application of laser technology in manufacturing fields.
激光清洗因其高效、无污染且易于自动化而受到广泛关注。然而，如何提高清洗质量已成为当前研究的重点。本文采用脉冲激光对Q235B碳钢进行清洗实验，研究不同工艺参数对表面清洗质量的影响。在此基础上，创新性地提出了一种新的清洗方法，以提高清洗样品的氧化物去除效率、微观结构和力学性能。结果表明，脉冲激光清洗Q235B碳钢在激光线宽为50mm、脉冲频率为500kHz、清洗速度为15mm/s时效果最佳。由于脉冲激光的热冲击，清洗后的样品表面形成了大量坑洼。与其他激光清洗方法相比，综合激光清洗在提高氧化物去除效率和降低表面粗糙度方面有明显效果。样品表面的脊状结构也能被成功消除，进而实现光滑结构。在测试样品表面附近形成了细晶结构，这显著降低了晶体取向，增加了小角度晶界数量和GND密度。硬度的提高主要归因于综合激光清洗样品中的晶粒细化。此外，还提出了一个物理模型来解释综合脉冲 - 连续激光清洗样品的氧化物去除机制。本研究可为解决激光清洗中长期存在的效率和质量问题提供新的理论和技术支持，从而显著拓宽激光技术在制造领域的应用。
