Page 88 - 摩擦学学报2025年第9期

1342 摩擦学学报（中英文） 第 45 卷

2. Center of Materials Science and Optoelectronics Engineering,
University of Chinese Academy of Sciences, Beijing 100049, China;
3. AECC South Industry Co, Ltd, Hunan Zhuzhou 412002, China;
4. National and Local Joint Engineering Research Center for Applied Technology of Hybrid Nanomaterials, Henan
University, Henan Kaifeng 475004, China)
Abstract: The feeding powders were prepared using AlO(OH) and graphite through hydroxylation, physical mixing, and
spray granulation, which were well agglomerated. Al 2 O 3 /C composite coating and Al 2 O 3 coating were prepared using
atmospheric plasma spraying (APS) technique. The microstructure and physical phase composition of the coatings were
studied systematically using scanning electron microscopy (SEM) and energy spectroscopy (EDS). The friction behavior
of Al 2 O 3 /C composite coatings and Al 2 O 3 coatings sliding against 316L stainless steel balls under different loads was
investigated using the UMT-3 friction wear tester. During the spraying process, the AlO(OH) phase in the AlO(OH)/C
composite powder was dehydrated and transformed into Al 2 O 3 phase, which was finally deposited on the substrate as the
Al 2 O 3 /C composite coating, with uniform composition distribution, fewer defects and good melt state. Due to the
dehydration of AlO(OH) and the oxidation of part of the graphite by the high-temperature flame flow, gaseous carbon
oxides were produced, the porosity of the Al 2 O 3 /C coating was higher than the porosity of the Al 2 O 3 coating. After dry
sliding friction test, the results showed that the friction coefficient of Al 2 O 3 /C coating was slightly lower than that of
Al 2 O 3 coating when the friction load was small (3 and 5 N), but the wear rate of composite coating was slightly larger than
that of alumina coating. However, the difference of friction coefficient was obvious when the load was increased (10 and
20 N), a maximum 32% reduction occurred in composite coatings, at the same time, the wear rate increased by about
36%. The friction surfaces of the composite coatings and stainless steel balls were characterized using Raman
spectroscopy, carbon transfer films were found on the friction surfaces of both the Al 2 O 3 /C coatings and the steel balls,
and no cracks appeared on the friction surfaces of the coatings. Due to the larger porosity and lower hardness of the
Al 2 O 3 /C composite coating, the wear rate of the Al 2 O 3 coating was slightly lower than that of the Al 2 O 3 /C composite
coating at different loads, however, when the friction load was changed from 3 N to 20 N, the wear rate of the Al 2 O 3
coating was increased by about 62 times, whereas the wear rate of the Al 2 O 3 /C composite coating increased by a factor
of only about 12 under the same conditions. Besides, the wear rate of the Al 2 O 3 coating was basically close to that of the
Al 2 O 3 /C composite coating after friction with 10 and 20 N loads. The wear rate of the 316L stainless steel ball decreased
gradually with the increase in load. When the load was 20 N, the wear rate of stainless steel balls rubbed with Al 2 O 3 /C
composite coating was lower than the wear rate of stainless steel balls rubbed with Al 2 O 3 coating. In terms of wear
mechanisms, the hardness of Al 2 O 3 coating was much larger than that of 316L stainless steel ball, so that its wear
mechanism was dominated by adhesive wear, accompanied by abrasive wear, and Al 2 O 3 /C composite coating was
dominated by abrasive wear due to the presence of a large number of hard particles of aluminum oxide being pulled out
of the friction surface.
Key words: atmospheric plasma spraying (APS); hydrotalcite; alumina coatings; alumina/graphite composite coatings;
friction wear

在复杂苛刻工况环境中，机械零部件因运动部件 氧化铝陶瓷作为1种在工业领域广泛应用的涂层
表面的严重磨损而导致失效，因此，减轻工件表面由 材料，因其高硬度、抗蠕变、优异的热稳定性和化学
于直接接触而发生的磨损对机械装备服役可靠性至 稳定性以及优异的耐磨性、抗氧化性和耐腐蚀性等特
[1]
关重要 . 在工件金属表面，利用大气等离子喷涂工艺 点，被广泛应用于航空、航天发动机的密封涂层以及
[6]
制备陶瓷涂层可以显著改善摩擦副之间摩擦学性能， 高速切削工具等领域中的耐磨耐腐蚀涂层 等. 但在
[2]
以此延长部件的使用寿命 . 由于等离子喷涂的陶瓷 实际工况中，氧化铝具有耐磨但不减摩性能，即不具
涂层具有高硬度和更优异的耐腐蚀特性，比传统的电 备润滑性的特点，因此与摩擦对偶之间具有较高的摩
镀硬铬具有更好的耐磨耐蚀性 [3-4] ，同时，通过喷涂粉 擦系数，特别是对金属部件的严重磨损是氧化铝涂层
末的复配还可以将一些具有优异自润滑能力的软材 在应用中存在的主要问题. 另外，在干摩擦条件下，摩
料(如石墨和聚四氟乙烯等)通过等离子喷涂技术制备 擦副之间高的摩擦系数导致氧化铝涂层发生塑性变
出具有一定自润滑特性的复合涂层，进一步达到减轻 形、脆性断裂和片状剥落是其失效的根本原因 [7-8] . 因
[5]
对机械零部件的磨损 . 此，如何赋予氧化铝涂层一定的润滑特性降低涂层与金