|利用光纤激光器在Q235钢上激光熔覆Ni包WC粉末增强Ni45合金涂层，系统研究了不同Ni包WC含量下熔覆层组织形貌、稀释率和显微硬度的变化规律。结果表明：WC颗粒受到激光辐照会发生熔解,并与周围元素相互作用形成低熔点共晶。随着Ni包WC含量的增加，熔覆层的稀释率逐渐增大，且熔覆层 γ -Ni枝晶持续增多且细化。随着Ni包WC含量的增加，熔覆层的平均显微硬度也逐渐增加，当未添加Ni包WC时，熔覆层显微硬度约为基体的3倍；当Ni包WC质量分数增加到30%时，熔覆层平均显微硬度可达到基体的4倍。
|关键词: Q235钢 激光熔覆 镍基合金 显微组织 显微硬度
|Effect of Ni - WC content on microstructure and property of laser cladding Ni 45/ Ni - WC composite coating
Zhao Jian 1 , Ma Bing 1 , Liu Guang 1 , Zheng Ziyun 1 , Li Tianyi 2
|The fiber laser has been used for cladding Ni-WC reinforced Ni-based alloy on Q235 steel. The microstructure, dilution rate and microhardness of the cladding layer with different Ni-WC content were studied systematically. The results showed that WC particles were dissolved by laser irradiation and interact with the surrounding elements to form eutectic with low melting point. The dilution rate and the γ -Ni dendrites content of cladding layer increased gradually with the increase of Ni-WC content. The grain of γ -Ni dendrites was refined at the same time. Meanwhile, the average microhardness of the cladding layer increased as well, which was about three times that of the substrate when weight percent of Ni-WC was 0%; while it can be four times that of the substrate when weight percent of Ni-WC was 30%.
|Key words: Q235 steel laser cladding Ni-based alloy microstructure microhardness