高速フレーム溶射したWC-Co皮膜のはく離強度に及ぼす基材硬さの影響

抄録

WC-Co cermet was coated on the steel substrates (JIS: SKD5, SKD62 and SS400) with different hardness by two types of spraying methods using high-velocity oxygen fuel (HVOF) and high-pressure high-velocity oxygen fuel (HP-HVOF). Tensile tests as well as Edge-indent tests were carried out to obtain interfacial fracture toughness G_C12 and delamination energy E_d, respectively. The G_C12 and E_d of the coatings deposited on the SS400 substrate with smaller hardness revealed larger values, and the G_C12 and E_d of the coatings deposited by HP-HVOF were higher than that by HVOF with the same hardness of substrate. The reason can be that the sprayed powder with higher speed more easily shot into the soft substrate than the hard substrate so that the mechanical bond effect along interface between coating and substrate was stronger.