灰铸铁激光熔覆纳米Al_2O_3的性能研究

Research on capability of casting iron surface by laser cladding nano-Al_2O_3

用纳米氧化铝和铁粉混合作为灰铸铁的表面改性材料,通过激光熔覆试验对灰铸铁进行表面改性,制备了灰铸铁表面改性试样。对试样进行了以磨损试验为主的性能测试,显微硬度测量结果表明表面改性层硬度明显提高,结合区由于成分及微观组织的改变,硬度提高异常显著。运用MM-200摩擦磨损试验机进行了的摩擦磨损试验,结果表明表面改性层耐磨性显著提高,且纳米氧化铝含量越多,耐磨性提高越显著。载荷越大,摩擦系数越小。灰铸铁激光熔覆纳米Al2O3后,其磨损机制为犁削磨损。

The mixtures of nano-Al2O3 and iron powder were chosen to serve as surface modification materials, and the surface modification of gray iron was carried out by means of laser cladding technology. The surface modification layer of gray iron containing nano-Al2O3 was prepared. The properties of sample were studied. The results of micro-hardness indicated that the hardness of surface modification layer was obviously improved, and the hardness of the interracial bonding layer was very obviously improved due to the change of the component and microstructure. A MM-200 wear machine was employed for wear experiment. It was found that the wear resistance of the surface modification layer was obviously improved, and the more the content of nano-Al2O3, the more obvious the improvement of wear resistance is. The friction coefficient decreases when the loads increase. The wear mechanism of the surface modification layer of gray iron was mainly ploughing wear.