摘要
目的提升航空发动机用常规高温润滑涂层的宽温域摩擦性能,设计微纳米Cr_(2)O_(3)填充NiCrAlY-Cr_(2)O_(3)-Mo-Ag@Ni复合涂层。方法运用化学镀法制备Ag@Ni粉体,通过等离子喷涂技术制备微纳米Cr_(2)O_(3)填充NiCrAlY-Cr_(2)O_(3)-Mo-Ag@Ni复合涂层。综合分析涂层的微观形貌、物相,以及在室温至800℃范围内的摩擦学性能。结果Ag@Ni粉体球形度良好、Ni包覆均匀。微纳米填充复合涂层在性能方面展现出显著优势,尤其是在孔隙率、显微硬度和耐磨性等方面,复合涂层的孔隙率明显降低,物相以(NiCr)、Ag、Mo、氧化物为主,微纳米填充复合涂层的显微硬度(304.17HV0.3~413.93HV0.3)均高于微米涂层(298.17HV0.3),耐磨性显著提高。微纳米填充复合涂层在摩擦学性能方面表现出显著的优越性,在室温下其摩擦因数均低于0.38,摩擦因数随着温度的升高而降低,这归因于涂层内部微观结构的优化及纳米颗粒的润滑作用。在不同温度下,磨损率随着银含量的增加而降低。在800℃时,微纳米填充涂层的磨损率为1.19×10^(-5)~1.33×10^(-5)mm^(3)/(N·m)。结论Ag的质量分数为20%的Ag@Ni复合涂层的润滑性能最佳,摩擦化学反应生成的高温润滑相NiMoO4、Ag2MoO4的协同润滑作用使得摩擦因数低至0.14,且微纳米Cr_(2)O_(3)填充的复合涂层在室温至800℃的宽温域内具有良好的润滑性。
To enhance the wide temperature range friction performance of conventional high-temperature lubricating coatings for aircraft engines,micro-nano Cr_(2)O_(3) filled NiCrAlY-Cr_(2)O_(3)-Mo-Ag@Ni composite coatings were designed.With NiCrAlY,Cr_(2)O_(3),Mo,and Ag@Ni core shell structure powder as coating materials,the composite coating was prepared by chemical plating method,which had good sphericity and a uniform Ni coating layer to suppress the diffusion of Ag at high temperature.Micro-nanostructures were prepared by plasma spraying technology.The spraying distance was 150 mm,the spraying current was 500 A,the spraying speed was 200 mm/s,and the spraying gas flow rate was 40 L/min.By optimizing the spraying parameters,the uniformity and density of the coating were ensured.A comprehensive analysis was conducted on the microstructure,phase composition,and tribological properties of the coating at room temperature to 800℃.The Ag@Ni powder had good sphericity,uniform Ni coating,uniform distribution of Cr_(2)O_(3) micro and nano powder,and excellent fluidity,which was conducive to plasma spraying.In addition,micro-nano composite coatings exhibited significant advantages in performance,particularly in porosity,microhardness,and bonding strength.Specifically,the porosity of the composite coating was significantly reduced,which not only reduced the internal defects of the coating,but also improved the density of the coating.The phase of the coating was mainly composed of(NiCr)solid solution phase,Ag,Mo,and oxide.The microhardness of the micro-nano composite coating(304.17-413.93HV0.3)was higher than that of the micro coating(298.17HV0.3),and the mechanical properties were significantly improved.Micro-nano composite coatings exhibited significant superiority in tribological properties.The coatings were tested for tribological properties with a reciprocating friction and wear tester in a wide temperature range from room temperature to 800℃,with a load of 30 N,a rotational speed of 60 r/min,and a testing time of 60 min.It was found that the friction coefficient at room temperature was lower than 0.38,and the friction coefficient decreased with the increasing temperature,attributed to the optimization of the internal microstructure of the coating and the lubricating effect of nanoparticles.The wear rate decreased with the increasing silver content at different temperatures.At 800℃,the wear rate of the micro-nano structure coating was 1.19×10^(-5)-1.33×10^(-5) mm^(3)/(N·m),with a content of 20%Ag@Ni.The composite coating had the best lubrication performance,with a friction coefficient as low as 0.14,and performed well over a wide temperature range.The good lubricity at high temperatures was attributed to the synergistic lubrication effect of high-temperature lubricating phases NiMoO4 and Ag2MoO4 generated by frictional chemical reactions.NiMoO4 had good high-temperature stability and lubrication performance,while Ag2MoO4 preferentially broke through its low-energy Ag-O bonds during friction,further enhancing the lubrication effect.This synergistic effect not only reduced the friction coefficient,but also decreased the wear rate,allowing the coating to maintain excellent wear resistance at high temperatures.These two compounds formed a stable lubricating film during the friction process,significantly reducing the friction coefficient and minimizing wear.By optimizing the Ag content and micro-nano structure design,the micro-nano structure NiCrAlY-Cr_(2)O_(3)-Mo-Ag@Ni composite coatings exhibit excellent tribological properties over a wide temperature range,providing an ideal material choice for high-temperature engineering applications.
作者
徐艺飞
贾均红
卫润泽
杨杰
何乃如
赵海潮
XU Yifei;JIA Junhong;WEI Runze;YANG Jie;HE Nairu;ZHAO Haichao(College of Mechanical and Electrical Engineering,Shaanxi University of Science&Technology,Xi'an 71002l,China;National Engineering Research Center for Remanufacturing,Army Academy of Armored Forces,Beijing 100072,China)
出处
《表面技术》
北大核心
2025年第21期215-225,236,共12页
Surface Technology
基金
国家自然科学基金(52175178,52305205)
陕西省自然科学基础研究计划(2022JQ-477)。
关键词
微纳米填充
复合涂层
宽温域
摩擦学性能
摩擦化学
micro-nano filled
composite coating
wide temperature range
triboelectric properties
tribochemistry
