45钢基体纳米陶瓷颗粒增强激光表面合金化组织和性能研究

Study of structure and properties of laser alloyed nanometer ceramic particle on the 45# steel substrate

本文采用万瓦横流CO激光器存45钢表断合金化纳米陶瓷颗粒，片采用SEM、XRD和最微维氏碰度进行了组织、截面轻微硬度和物相分析．结果表明：采用合金化技术完全可以将陶瓷颗粒添加到基体材料中，形成新的合金层，合金化层组织致密、晶粒细小、无裂纹、孔隙夹杂等缺陷．具有树枝晶及胞状晶结构，南FeB，TiC、马氏体棚及少量的Fe3C组成，轻微硬度高达940Hv。同时，通过磨损试验对比合金化前后的失重量情况，结果表明合金化后耐席损性能有明显的提高，提高了约1．7倍，达到表面改性的目的。

The nanometer particle was applied on the 45 steel＇ s surface by ten-thousand-watts transverse flow CO2 laser in this paper. After that the microstructure and properties were studied by means of SEM, XRD, Optical Microscope, and micro-hardness meter. The results show that it is possible to distribute the ceramic particles into laser alloying layer to get a totally new layer, which has advanced properties such as denser structure, smaller grain, crack-free and porosity-free, etc. The laser alloying layer, which consists of isometric grain, dendritic structure and parasporal crystal, including enforced particles such as FeB, TiC, lath martensite and Fe3C, etc, was metallurgically bonded each other and with the substrate. The micro-hardness of the alloying layer reach 940Hv, and the wear resistance is 1.7 times higher than the substrate before treatment when compared the weight loss. The laser alloying process is one of the best surface modification technic can be adopted in industry to increase the wear-resistance.