Ductile iron has unique mechanical property and has been widely used in many industrial applications, e.g., engine cylinder covers, crank axles, and machine tool beds and cams. The welding performance of ductile iron is normally influenced by graphite particles in the surface of ductile iron, which needs to be removed before welding. In this article, laser cleaning technique was developed to remove graphite particles implanted in the surface of ductile iron. Laser cleaning parameters and the damage threshold value of the substrate were investigated by using a pulsed Nd: YAG laser. The optimized laser cleaning parameters were obtained to achieve high-quality cleaning effect and avoid the formation of the oxide layer. Surface morphologies and elemental compositions of specimens before and after laser cleaning were characterized by scanning electron microscopy and energy-dispersive X-ray spectroscopy. Results indicated that graphite particles implanted in the surface of ductile iron were removed completely and efficiently by using the pulsed laser without the protection of inert gas atmosphere, and surface oxidation was not observed during the laser cleaning process.

中文翻译：

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新型方法清除球墨铸铁表面嵌入的石墨颗粒

球墨铸铁具有独特的机械性能，并已广泛用于许多工业应用中，例如，发动机汽缸盖，曲轴，机床床身和凸轮。球墨铸铁的焊接性能通常受球墨铸铁表面的石墨颗粒影响，焊接前需要将其清除。在本文中，开发了激光清洁技术以去除植入在球墨铸铁表面的石墨颗粒。使用脉冲Nd：YAG激光研究了激光清洁参数和基材的损伤阈值。获得了优化的激光清洗参数，以实现高质量的清洗效果并避免形成氧化层。通过扫描电子显微镜和能量色散X射线光谱对激光清洗前后的样品表面形貌和元素组成进行了表征。结果表明，在没有惰性气体保护的情况下，利用脉冲激光可以完全有效地去除球墨铸铁表面植入的石墨颗粒，并且在激光清洗过程中未观察到表面氧化。