Microstructure and properties of high velocity oxygen fuel sprayed (WC-Co)-Ni coatings
Microstructure and properties of high velocity oxygen fuel sprayed (WC-Co)-Ni coatings
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DOI：
10.1016/j.ceramint.2020.03.021
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发表时间：
2020-07
影响因子：
5.2
通讯作者：
W. Fu;Qingqing Chen;Chao Yang;D. Yi;H. Yao;Hongtao Wang;G. Ji;F. Wang
中科院分区：
文献类型：
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作者：
W. Fu;Qingqing Chen;Chao Yang;D. Yi;H. Yao;Hongtao Wang;G. Ji;F. Wang
将团聚后的(WC-Co)-Ni粉末与镍粉混合，采用超音速氧气喷涂工艺制备了(WC-Co)-Ni复合涂层。采用扫描电子显微镜(SEM)和X射线衍射仪(XRD)对不同镍粉含量的镀层进行了微观结构和相组成的表征。用压痕法测试了涂层的显微硬度、弹性模量和断裂韧性。用改进的销盘式磨损试验机测试了涂层在干、湿条件下以及在不同载荷下的磨损性能。结果表明，超音速火焰喷涂(WC-Co)-Ni复合涂层的显微组织呈现出由变形的WC-Co片层和均匀分布的Ni片层组成的片层特征，这与原始粉末中的Ni含量有显著的关系。涂层的相组成主要由WC、W2C、Co、Ni和少量Co6W6C组成，这与原始粉末中的Ni含量有关。涂层的显微硬度、弹性模数、断裂韧性和磨损率分别为435.5±34.7~708.7±43.3Hv0.3，58.9Hv0.3~135.0±82.7Hv0.3，1.07±0.11~2.41±0.09−·m1/2，0.15~0.4 mg·(Nm)Hv1。涂层的磨粒磨损主要以刨削和剥落为主，也有少量塑性变形。
The (WC-Co)-Ni composite coatings were fabricated by high velocity oxygen fuel (HVOF) spraying process using (WC-Co)-Ni powders prepared through blending agglomerated WC-Co powder with Ni powder. Microstructure and phase composition of the coatings deposited with different content of Ni powders were characterized using scanning electronic microscopy (SEM) and X-ray diffraction (XRD), respectively. The microhardness, elastic modulus and fracture toughness of the coatings were tested by indentation method. The wear properties of the coatings sliding in dry and wet conditions as well as under different applied loads were tested using a modified pin-on-disc tester. Experimental results showed that the microstructure of HVOF sprayed (WC-Co)-Ni composite coating was exhibited some lamella features consisted of deformed WC-Co splats and even distributed Ni splats, which was significantly influenced by the Ni content in original powders. Phase constitutions of the coatings mainly consisted of WC, W2C, Co, Ni and a little of Co6W6C, which were related to the Ni content in original powders. Microhardness, elastic modulus, fracture toughness and wear rate of the coatings were varied from 435.5 ± 34.7 to 708.7 ± 43.3 Hv0.3, from 58.9 ± 10.3 to 135.0 ± 82.7 GPa from 1.07 ± 0.11 to 2.41 ± 0.09 MPa m1/2and from 0.15 to 0.4 mg•(Nm)−1, respectively. The abrasive wear of the coating occurred mainly in the form of gouging and peeling off in addition to a little of plastic deformation.