Effect of Decarburized Layer of Tool Steel on Delamination Strength of WC-Co Thermally Sprayed Coating
Effect of Decarburized Layer of Tool Steel on Delamination Strength of WC-Co Thermally Sprayed Coating
复制标题
工具钢脱碳层对WC-Co热喷涂层分层强度的影响
DOI：
--
复制
发表时间：
2004
期刊：
影响因子：
--
通讯作者：
K. Nakasa
中科院分区：
文献类型：
--
作者：
Chengwei Li;Masahiko Kato;K. Nakasa
对SKD5工具钢进行了1323K加热，最大5.4K，淬火，873K，3.6K回火的脱碳处理。这导致了最大厚度为0.45 mm的脱碳层。经处理后，采用高速氧燃料热喷涂沉积了0.2 mm厚的WC-Co金属陶瓷。对试件进行拉伸试验，载荷平行于试件。结果表明，脱碳层的存在提高了界面断裂韧性。其原因似乎是由于脱碳层的大塑性变形消除了裂纹尖端的剪应力和拉应力。还进行了边缘压痕试验，涂层在压头侵彻过程中发生了剪切剥落。结果表明，由于脱碳层的存在，分层能降低，这与拉伸试验的结果相反。软脱碳层的剪切断裂可能是脱碳试件分层能较小的原因。
Decarburization treatment was carried out on SKD5 tool steel by heating at 1323K for maximum 5.4ks and quenching followed by tempering at 873K for 3.6ks. This resulted in decarburized layer of maximum thickness 0.45mm. After the treatment, WC-Co cermet of 0.2mm thickness was deposited by high-velocity oxygen fuel thermal spraying. Tensile tests were carried out on the specimens, where the load was applied parallel to the specimen. The results show that the presence of decarburized layer increases the interfacial fracture toughness. The reason seems to be that the large plastic deformation of decarburized layer relieves shear and tensile stresses at crack tip. Edge indent tests were also conducted, where shear delamination of coating occurred during the penetration of indenter. The result is that the delamination energy decreases due to the presence of decarburized layer, which is contrary to that of the tensile test. The shear fracture of soft decarburized layer may be the reason for the smaller delamination energy of decarburized specimen.