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高温封严涂层在腐蚀环境中的摩擦磨损是影响其服役寿命的主要问题之一。为此,研究了微弧等离子堆焊沉积Ni/硅藻土封严涂层的工艺规律与腐蚀摩擦学性能。对粉末和涂层的基本结构的表征显示:涂层呈现堆叠结构,含有大量孔隙,涂层主要由Ni,SiO_2和少量NiO组成。涂层的内聚强度平均达到8.78MPa,在拉伸应力作用下表现为以扁平化粒子边缘为主,沿着孔隙率方向应力集中的脆性断裂,以及在应力集中部位导致硅藻土粒子内部的穿晶断裂。当堆焊电流为40A时,微弧等离子堆焊制备的Ni/硅藻土封严涂层在盐环境和酸环境的摩擦系数和磨损率分别达到0.524,16.354wt.‰和0.5099,17.317wt.‰。Ni/硅藻土可磨耗封严涂层在酸性环境的腐蚀能力较低,其平衡电位达到-708m V。
Friction and wear of high-temperature seal coating in corrosive environment is one of the main problems that affect its service life. For this reason, the technological rules and corrosion tribological properties of Ni / diatomite seal coatings deposited by micro-arc plasma deposition were studied. Characterization of the basic structure of the powder and coating showed that the coating presents a stack structure with a large number of pores and the coating mainly consists of Ni, SiO 2 and a small amount of NiO. The cohesive strength of the coating reached an average of 8.78MPa, under the action of tensile stress, the brittle fracture mainly focused on the edge of the flattened particle and concentrated along the porosity direction, and the stress concentration in the diatomite particles Transgranular fracture. When the welding current is 40A, the friction coefficient and wear rate of Ni / diatomite sealant prepared by micro-arc plasma surfacing in salt environment and acid environment reach 0.524, 16.354wt. ‰ and 0.5099, 17.317wt. ‰. Ni / diatomaceous earth abrasion seal coating corrosion resistance in acidic environment is lower, the equilibrium potential of -708mV.