铁碳合金表面激光熔覆的研究进展

摘要

Laser cladding technology (LCT)has the advantages of fast heating speed,small heat affected zone,and low surface temperature of the substrate,thus it can better ensure the dimensional accuracy of parts.In recent years,it has become a widely used technique for surface modification.Laser cladding technology has no requirements for coating powder and matrix material, therefore,it is extensively applied to remanufacture and repair different kinds of components.In this paper,the research status of laser cladding are summarized from the point of iron carbon alloy materials,including cast iron,carbon steel and alloy steel parts. The applications of laser cladding in improving the mechanical properties,wear resistance,corrosion resistance and fatigue resistance of materials are also reviewed.Besides,the problems existing in this technology are proposed and the countermeasures are pointed out.And the conditions for preparing high quality cladding layer are given from aspects of strictly control of process parameters, optimization of material composition and preheat of work-piece or post-processing etc.Finally,the existing problems of current research about laser cladding are pointed out and the future development is also proposed.%激光熔覆技术具有加热速度快、熔覆过程中产生的热影响区小、基体表面温度低等优点,因此能够较好地保证零部件的尺寸精度,近年来发展成广泛应用的表面改性技术.激光熔覆技术对涂层粉末以及基材选择要求不高,因此广泛应用于不同种类基体材料的再制造修复.从铁碳合金材料出发,分别对激光熔覆技术在改善铸铁、碳钢及合金钢材料的力学性能、耐磨性、耐蚀性、抗热疲劳性等方面的应用进展和存在的问题及对策进行了分析,阐明了工艺参数、材料成分以及工件的预热或后处理对制备高质量大熔覆层组织和性能的影响规律,最后指出了激光熔覆技术在目前研究中存在的问题并对其未来发展方向进行了展望.