真空熔覆WC颗粒增强复合涂层中WC溶解行为的研究

Dissolution Behavior of WC in WC Reinforced Composite Coatings

研究了真空熔覆条件下三种不同成分镍基WC复合涂层中WC颗粒的溶解行为。结果表明:Ni60A-WC复合涂层中,WC的溶解从边缘发生,以复合碳化物Fe6W6C的析出为主;Ni25B-WC复合涂层中,WC溶解方式表现为整体的"疏松分离"、部分WC的桥接及团聚;Ni22AA-WC复合涂层中,WC仅发生局部的疏松溶解。WC中W,C和基体中W,C含量的浓度差大,基体中Cr,Fe含量高,都会加速WC颗粒的溶解行为。

The dissolution behavior of WC in three different nickel matrix systems is investigated. The results show that the dissolution occurs at the rim of WC with the precipitation of Fe6W6C in Ni60A- WC coatings; WC are loosely-separated, bridge-bonded and reunited to coarse carbide groups in Ni25B-WC coatings; in Ni22AA-WC coatings the WC are slightly dissolved in some locations. The larger concentration gradient of W and C between WC particles and matrix, and higher Cr and Fe contents will accelerate the dissolution of WC particles.