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采用高效能超音速等离子喷涂沉积Ni-C及Ni Cr Al-BN可磨耗封严涂层,对比研究两种涂层的抗冲蚀磨损、耐腐蚀及摩擦磨损性能。结果表明:两种涂层中的润滑相均匀分布在金属连续相之中,但与Ni-C涂层相比,Ni Cr Al-BN涂层中的润滑相尺寸较为细小,表面硬度较高。当冲蚀角度由30°增加到90°后,两种涂层冲蚀磨损失重量明显提高。Ni Cr Al-BN涂层的相对冲蚀速率约为Ni-C涂层的50%,表明Ni Cr Al-BN涂层具有较为优良的抗冲蚀性能。Ni-C涂层在稀盐酸中(1vol%)发生了明显的电化学腐蚀,在石墨片周围容易形成腐蚀产物;酸液会沿Ni Cr Al-BN涂层中的孔隙渗入,从而造成金属的局部腐蚀,但腐蚀程度明显较Ni-C轻。随着环境温度的升高,以BN为主的第二相润滑组元的塑性和流动性增强,使摩擦表面原本较小的、不连续的润滑型保护膜逐渐铺展开来,形成面积较大且呈连续分布的鳞片状自润滑保护膜。原来在较低温度下润滑膜中存在的裂纹、疏松或剥离等缺陷明显减少,导致Ni Cr Al-BN涂层摩擦系数大幅度降低,从而显示出优异的高温自润滑性能。
High-performance supersonic plasma spray deposition Ni-C and Ni Cr Al-BN can wear seal coating, comparative study of the two coatings erosion resistance, corrosion resistance and friction and wear properties. The results show that the lubricating phases in the two coatings are uniformly distributed in the metallic continuous phase. However, compared with the Ni-C coating, the lubricating phase in the Ni-Cr Al-BN coating is relatively small in size and has a higher surface hardness. When the erosion angle increased from 30 ° to 90 °, the abrasion loss weight of both coatings increased significantly. The relative erosion rate of the NiCr Al-BN coating is about 50% of that of the Ni-C coating, indicating that the NiCrAl-BN coating has better erosion resistance. The Ni-C coating undergoes significant electrochemical corrosion in diluted hydrochloric acid (1 vol%) and easily forms corrosion products around the graphite sheet; the acid penetrates into the pores in the Ni Cr Al-BN coating, causing the metal Local corrosion, but the corrosion was significantly lighter than Ni-C. With the increase of ambient temperature, the plasticity and fluidity of the second-phase lubricating component mainly composed of BN is enhanced, so that the originally smaller and discontinuous lubricating type protective film on the friction surface gradually spreads to form a larger area And was continuously distributed scale-like self-lubricating protective film. The defects such as cracks, looseness or peeling originally existed in the lubricating film at the original low temperature obviously reduce the friction coefficient of the Ni Cr Al-BN coating, thereby showing excellent high-temperature self-lubricating property.