摘要
采用预置涂层和同轴送粉激光熔覆方法,分别以Ta/W混合粉末和纯W粉末为熔覆材料,纯Ta为基底,在Ta板上制备Ta-W合金涂层,对难熔金属材料的激光熔覆工艺方法进行了对比研究。利用扫描电镜(SEM)、能谱仪(EDS)及显微硬度计对两种方法所制备熔覆层的微观组织和显微硬度进行了分析。结果表明,预置粉末法激光熔覆层厚度均匀,稀释率低,涂层内部为粗大的Ta-W合金固溶体组织,熔覆层平均硬度为1500HV,高于基底10倍。同轴送粉法激光熔覆层与基底呈良好的冶金结合,熔深较大,涂层内部为致密细小的树枝状Ta-W合金固溶体,均匀分布于Ta中。涂层平均硬度为800HV,为基材的5倍。
Ta-W alloy coatings were deposited on pure Ta plate by laser cladding with pre-coating and coaxial powder injection respectively in order to find the effects with two technique. The microstructure of the coatings was analyzed using scanning electron microscopy （SEM） and energy dispersive spectroscopy （EDS）. The microhardness was examined by hardness tester. The clad layer which formed with pre-coating had a microstructure of coarse columnar grain and low dilution rate with the substrate. The average microhardness of the clad layer was 1500 HV, it was 10 times greater than the Ta substrate. The clad layer deposited with coaxial power injection had a microstructure consisting of dendrite Ta-W solid solution uniformly dispersed in the Ta matrix. The average microhardness of the clad layer was approximately 800 HV and it was 5 times greater than that of the substrate.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2011年第8期105-110,共6页
Chinese Journal of Lasers
基金
国家自然科学基金(10832011)资助课题
