球墨铸铁变换激光束淬火性能的研究

Properties of Ductile Iron Modified by Laser Surface Hardening with Optical Changing of Laser Beam

采用经过二元光学元件变换呈二维点阵7×7分布的脉冲激光束对球墨铸铁材料进行表面淬火处理,研究激光参数变化对铸铁表面的粗糙度、硬化层深度、显微硬度和耐磨性等的影响。结果表明,在一定的能量范围内,随着能量的增加,粗糙度略呈增长的趋势,硬化层深也略有增加,并存在一个硬化层深极限值。硬度峰值差别很小,而相变硬化区差别则很大。耐磨性试验表明,随着能量的增加,耐磨性有提高的趋势。

Ductile iron was surface hardened by Nd ：YAG pulsed lasers equipped with diffractive optical element（DOE） which produces a 7 ×7 two dimensional array. The effects of laser treatment on roughness,hardened layer depth,distribution of hardness and wear resistance of the ductile iron were studied. The results show that the roughness, hardened layer depth and wear resistance increase with laser energy change, and there is a ultimate point of hardened layer depth by laser hardening. The maximal hardness is almost equal but there is difference with the laser hardened transition zone. Wear resistance test shows that there is an increasing trend of resistance to abrasion with increase of laser energy.