目的 加入 h-BN 和团聚聚苯酯分别作为固体润滑剂和造孔剂,以提高 NiCrAlYSi 基封严涂层的高温摩擦磨损性能。 方法 采用真空熔炼雾化造粒和料浆喷雾造粒技术制备 NiCrAlYSi/ h-BN 聚苯酯复合粉体,再利用大气等离子喷涂技术制备高温可磨耗封严涂层,通过扫描电子显微镜(SEM)、能谱仪(EDS)、CSM 摩擦磨损试验机和三维轮廓仪等手段,研究 NiCrAlYSi/ h-BN 封严涂层显微结构、元素组成以及室温和 800 ℃下的摩擦磨损性能,探究涂层在室温和 800 ℃ 下的磨损机理。 结果 等离子喷涂NiCrAlYSi/ h-BN封严涂层组织比较均匀,涂层结合强度可达 15 MPa,孔隙率约为 32% 。 室温下封严涂层与 DD6 镍基单晶高温合金球间的平均摩擦因数为 0. 897,涂层磨损体积为 2. 09×108 μm3;800 ℃ 高温下平均摩擦因数为 0. 425,涂层磨损体积为 3. 22×108 μm3;封严涂层 800 ℃下有良好的可磨耗性,相应对偶件的磨损较轻;高温下,封严涂层金属基相软化、h-BN 的润滑作用和部分金属基相高温下生成自润滑性氧化物,是摩擦因数降低和对偶件磨损较轻的主要原因。 NiCrAlYSi/ h-BN 封严涂层室温的主要磨损机理为涂抹、磨粒磨损和轻微氧化,高温下的主要磨损机理为切削、塑性变形、氧化和粘着磨损。 结论 等离子喷涂 NiCrAlYSi/ h-BN 高温封严涂层在高温下的可磨耗性能较好。

Objective To improve the tribological properties of the NiCrAlYSi based seal coatings by adding h-BN and polyester into the coatings as lubrication and pore forming material, respectively. Methods The NiCrAlYSi / h-BN / polyester composite powder was prepared by the technology of vacuum melting atomization and spray granulation. The NiCrAlYSi / h-BN high-temperature abradable seal coatings were prepared by atmospheric plasma-spray technology. The microstructure, elements and tribological properties at room temperature and 800 ℃ of coatings were studied by SEM,EDS,CSM tribometer and three-dimensional contour instrument. The tribological mechanisms of the coatings were investigated at room temperature and 800 ℃ . Results The NiCrAlYSi / h-BN abradable seal coatings had uniform microstructure and the tensile strength of the coatings was about 15 MPa. The porosity of the coating was about 32% . The room-temperature average friction coefficient between NiCrAlYSi / h-BN and DD6 alloy ball was 0. 897, and the average friction coefficient at 800 ℃ was 0. 425. The wear volume of the coatings at room-temperature and 800 ℃ was 2. 09×108 μm3 and 3. 22×108 μm3 , respectively. The wear performance of the coating at 800 ℃ was good and the abrasion of DD6 alloy ball was slight, which was due to the softened metal matrix phase, the lubrication of h-BN lubricant material and the formation of metallic self-lubricant oxide at high temperature. The main room-temperature wear mechanisms of NiCrAlYSi / h-BN coating were smearing, particle wear and slight tribo-oxidation; while the main wear mechanisms at high temperature were cutting, plastic deformation, tribo-oxidation and adherence wear. Conclusion The NiCrAlYSi / h-BN high temperature abradable seal coatings exhibited excellent wear performance at high temperature.