H13挤压铸造模具激光熔覆Al_2O_3的组织与性能

Microstructure and Property of H13 Squeeze Casting Mould Laser Cladding Al_2O_3

为了解决挤压铸造模具在机械应力和热应力的复合作用下寿命较低的问题,采用激光熔覆Al2O3粉末对H13钢表面进行强化,获得连续平整的熔覆层,涂层与基底形成了良好的冶金结合。研究结果表明:基体为回火索氏体并其中分布着细小点状合金碳化物,结合区无裂纹、孔洞等缺陷,熔覆层出现条状及块状马氏体组织和未熔化的Al2O3。材料的硬度由熔覆层到热影响区逐渐降低,激光熔覆后的磨痕宽度和磨损失重量均显著降低。

In order to solve the problem of the Squeeze Casting Mould lower life induced by the complex interaction of the mechanical stress and heat stress, the Laser Cladding Al2O3 power is used on the surface of the H13 steel to obtain the continuous cladding layer and the better alloying bonding between layer and matrix. The investigation results show that the alloys matrix is the tempered sorbite, and the refining spotty element carbide is distributed on the surface. The crack and hole defect are not found in the bonding zone, and the cladding layer is composed of the strip, bulk martensite and the unmelted Al2O3. The hardness of materials decreases from cladding zone to heat affected zone, and the wear scar width and weight loss all decrease obviously.