采用高效能超音速等离子喷涂沉积Ni-C及NiCrAl-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， NiCrAl-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。NiCrAl-BN涂层的相对冲蚀速率约为Ni-C涂层的50%，表明NiCrAl-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NiCrAl-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NiCrAl-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-efficiency supersonic atmospheric plasma spraying was used to fabricate Ni-C and NiCrAl-BN abradable seal coatings. The erosion wear, corrosion resistance and wear resistance of plasma-sprayed coatings were comparatively studied.Experimental results showed that the libricating phases were homogeneously distributed in the as-sprayed coatings while their average size of the coating was much fine compared with Ni-C coating, and the former also showed higher surface hardness than the latter. Meanwhile, it was found that the erosive mass loss increased with the increase of impingement angle from 30° to 90° and the relative erosion rate of NiCrAl-BN coating was only a half of that of Ni-C coating. Due to the formation of corrosion product around the flake graphite, the corrosion resistance of NiCrAl-BN coating was better than Ni-C coating in dilute hydrochloric acid (1vol%). However, the hydrochloric acid could permeate the NiCrAl-BN coating through the pores, which resulted in the localized corrosion of metal phases. In addition, we also observed that the friction coefficient of NiCrAl-BN coating significantly decreased from room temperature to 400℃ owing to the formation of large-scale self-lubricating film that resulted from the improvement of plasticity and fluidity of BN.
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