纳米WC增强Ni基合金喷熔层组织结构与抗磨粒磨损特性

发布时间：2019-03-19 20:43

【摘要】：目的研究纳米WC对Ni基合金喷熔层抗磨粒磨损性能的影响。方法采用扫描电镜、X射线衍射分析了氧乙炔火焰喷熔Ni基合金层和两种不同结构WC增强Ni基合金喷熔层的微观组织和相结构,并通过磨粒磨损试验平台对三种涂层进行磨损性能测试。结果纳米WC粉末的加入,能有效提高喷熔层的宏观硬度。通过组织分析得出纳米WC增强Ni基喷熔层中除含有γ-(Ni,Cr)固溶体、Cr的碳化物、硼化物以及微米级WC颗粒之外,还含有一定量的纳米WC团聚体和少量高硬度的W_2C相。磨粒磨损实验结果显示,纳米WC增强Ni基喷熔层的磨损失重分别为Ni60和NiWC35涂层失重的56%和73%。对比磨损后涂层的表面微观形貌可知,纳米WC颗粒在涂层中能有效降低磨粒压入喷熔层的深度,从而控制磨粒对喷熔层的犁削量。结论纳米WC增强Ni基合金喷熔层中含有的γ-(Cr,Ni)固溶体、Cr_(23)C_6、Cr_7C_3、Cr_3Ni_2及未熔化的WC颗粒和WC脱碳形成的W_2C等硬质相,使镍基自熔合金涂层的硬度有较大提高,同时也大大提高了涂层的抗磨粒磨损性能。
[Abstract]:Objective To study the effect of nano-WC on the wear resistance of Ni-based alloy spray coating. Methods The microstructure and phase structure of the oxygen-acetylene flame-sprayed Ni-based alloy layer and the two different WC-reinforced Ni-based alloy meltblown layers were analyzed by means of scanning electron microscope and X-ray diffraction, and the wear properties of the three coatings were tested by the abrasive wear test platform. As a result, the nano-WC powder is added, and the macro-hardness of the meltblown layer can be effectively improved. In addition, a certain amount of WC aggregates and a small amount of W _ 2C phase are contained in the WC-reinforced Ni-based meltblown layer, in addition to the carbon-containing (Ni, Cr) solid solution, the carbide of Cr, the boride and the micron-sized WC particles. The results of the abrasive wear experiment show that the weight loss of the WC-reinforced Ni-based meltblown layer is 56% and 73% of the weight loss of the Ni60 and NiWC35 coatings, respectively. Compared with the surface micro-morphology of the wear-resistant coating, the nano-WC particles can effectively reduce the depth of the abrasive particles into the spray-and-melt layer in the coating, so as to control the amount of the abrasive grains to cut the coal plough layer. It is concluded that the hardness of the Ni-based self-fluxing alloy coating is greatly improved by the hard phases such as Fe-(Cr, Ni) solid solution, Cr _ (23) C _ 6, Cr _ 7C _ 3, Cr _ 3Ni _ 2 and non-melted WC particles and W _ 2C, etc. And meanwhile, the wear resistance of the coating is greatly improved.
【作者单位】：武汉理工大学能源与动力工程学院;
【基金】：国家自然科学基金(51422507)~~
【分类号】：TG174.4

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