激光熔覆Ta-W合金组织及高温气动烧蚀性能

Microstructure and High Temperature Aerodynamic Ablation Property of Ta-W Alloy Deposited by Coaxial Laser Cladding

以纯W粉末为熔覆材料,纯Ta为基底,采用同轴送粉激光熔覆技术在Ta板侧面制备了Ta-W合金涂层。利用扫描电镜(SEM)、能谱(EDS)及显微硬度计对熔覆层的微观组织和显微硬度进行了分析,在直联式自由射流风洞试验台上对涂层的抗高温高速气流烧蚀性能进行了测试。结果表明,熔覆层与基底冶金结合,涂层内部为致密的树枝状Ta-W合金固溶体,大致均匀地分布于Ta中。Ta-W合金涂层平均HV硬度8GPa,为基材的5倍,同时抗烧蚀性能得到了显著提高。

A Ta-W alloy coating was deposited on pure Ta plate by coaxial laser cladding, using tungsten powder as cladding material. The microstructure of the coating was analyzed by scanning electron microscopy （SEM） and energy disperse spectroscopy （EDS）. The microhardness was examined by hardness tester. The high temperature hypersonic flow ablation property was tested in the wind tunnel system. It is found that the coating is metallurgically bonded with the substrate. The clad layer has a microstructure consisting of dendrite Ta-W solid solution uniformly dispersed in the Ta matrix. The average microhardness of the clad layer is approximately 8 GPa and it is 5 times greater than that of the Ta substrate. The ablative property is also obviously improved.