| 引用本文: | 张梓轩,侯国梁,万宏启,马俊凯,冶银平,周惠娣,陈建敏.环氧树脂改性对聚酰胺酰亚胺涂层抗空蚀性能的影响[J].中国表面工程,2024,37(5):88~101 |
| ZHANG Zixuan,HOU Guoliang,WAN Hongqi,MA Junkai,YE Yinping,ZHOU Huidi,CHEN Jianmin.Effect of Epoxy Resin Modification on the Cavitation Erosion Resistance of Polyamide-imide Coatings[J].China Surface Engineering,2024,37(5):88~101 |
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| 摘要: |
| 空蚀是局部高压和热引起的一种极端条件下的材料损伤现象，广泛存在于泵等过流部件中，严重制约着零部件服役寿命。由于航空航天轻量化要求涉及的轻合金耐受温度较低，常在解决空蚀损伤的聚酰胺酰亚胺（PAI）中添加环氧树脂（EP） 以降低固化温度，然而这对空蚀性能的影响尚不清楚。针对该问题，分别制备纯 PAI 涂层（P-280）和不同含量 EP 改性的 PAI 涂层（P-200 和 P-170），通过加速空蚀试验对比研究样品的空蚀性能，采用 XPS、TGA、纳米压痕、SEM 等表征分析了样品的力学和热学性能以及空蚀作用下的力 / 热响应行为和涂层空蚀前后的形貌，剖析损坏机理。结果表明，添加 EP 可使 PAI 的固化温度显著下降 80~110 ℃，但韧性由 P-280 的 8.21 mJ·m?3逐渐降低到 P-170 的 3.18 mJ·m?3 ，造成涂层在空化载荷冲击下更易发生疲劳开裂。同时，添加 EP 后的 PAI 的热稳定性也明显劣化，空蚀 30 min 后，P-170、P-200 和 P-280 样品材料失重 5%所对应的温度下降幅度约为 15.24%、14.82%和 9.05%，进一步加速涂层表面力学性能劣化及空蚀损坏。因此，P-200 和 P-170 在加速空蚀 30 min 后的质量损失分别为 1.7 和 3.6 mg，是 P-280 的 2.1 和 4.5 倍。综合考虑涂层的固化温度和耐空蚀性能， P-200 更适合在轻合金部件表面应用。探究不同涂层的综合性能与空蚀性能之间的关系为 PAI 涂层的研发提供了新思路。 |
| 关键词: 空蚀 聚酰胺酰亚胺 环氧树脂 力学性能 疲劳机理 |
| DOI：10.11933/j.issn.1007-9289.20231113001 |
| 分类号:TQ317 |
| 基金项目:中国科学院战略性先导科技专项（XDB0470102）；中央引导地方科技发展资金（23ZYQA0320）；中国科学院青年创新促进会会员项目（2020416）；陇原青年英才 |
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| Effect of Epoxy Resin Modification on the Cavitation Erosion Resistance of Polyamide-imide Coatings |
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ZHANG Zixuan1，2，HOU Guoliang1，WAN Hongqi1，MA Junkai1，YE Yinping1，2，ZHOU Huidi1，2，CHEN Jianmin1，2
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1.State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy ofSciences, Lanzhou 730000 , China ；2.College of Materials Science and Opto-Electronics Technology, University of Chinese Academy of Sciences,Beijing 101408 , China
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| Abstract: |
| Cavitation is a phenomenon of material damage under extreme conditions of localized high pressure and heat. It commonly occurs in pumps and other flow-through components and can severely limit the service life of these parts. Polyamideimide (PAI) coatings were originally developed to prevent cavitation erosion damage in steel components. However, because of their lightweight requirements in aerospace, they are now being used as light alloys that can withstand low temperatures. Notably, PAI coatings have high curing temperatures that exceed the withstanding temperatures of most lightweight alloys. Although the addition of epoxy resin (EP) is expected to significantly reduce the curing temperature of PAI, it may also alter its overall properties. The corresponding effect on cavitation erosion performance is currently unknown. To address this issue, we prepared pure PAI coatings (P-280) and EP-modified PAI coatings (P-200 and P-170) with varying PAI contents. Using an ultrasonic vibration-accelerated cavitation erosion test, we then compared the cavitation erosion performances of the samples. Through characterization using X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), and nanoindentation, we also analyzed the mechanical and thermal properties of the samples and their force / heat response behaviors under the effects of cavitation load and cavitation heat. This study investigated the mechanical and thermal properties of the samples and their force-and heat-response behaviors using three-dimensional optical shaping. The results indicated that the addition of EP could significantly reduce the curing temperature of PAI by 80–110 ℃. However, this reduction led to the destruction of the mechanical properties of the material, including its toughness, which decreased to 8.21, 5.50, and 3.18 mJ·m?3 in P-280, P-200, and P-170, respectively. This occurred because of the reduction in rigid molecular chains, such as the imide and benzene rings. In P-280, P-200, P-170, the tensile strength decreased gradually from 114.11 to 75.52 and 70.74 MPa. This reduction in strength led to a decrease in the bearing capacity of the coating and increased fatigue cracking under cavitation load, resulting in the formation of a greater number of larger spalling pits. However, the addition of EP significantly degraded the thermal stability of PAI, making it susceptible to melting and decomposition under cavitation heat. The reductions in temperature corresponding to a 5% weight loss of the P-170, P-200, and P-280 samples after 30 min of cavitation erosion were 15.24%, 14.82%, and 9.05%, respectively. This further accelerated the degradation of the mechanical properties of the coating surface and the damage caused by cavitation erosion. In addition, the heat generated by cavitation erosion promoted pyrolysis and hydrolysis of the molecular chains. XPS results indicated a reduction in the oxygen content after 30 min of cavitation erosion. Specifically, P-280, P-200, and P-170 decreased by 0.67, 1.9, and as much as 3.33at.%, respectively. The breakage of the molecular chains further deteriorated the overall performance of the coatings. The SEM morphology of the P-170 flaking debris showed melting under the heat of cavitation and the subsequent condensation of water into spherical debris particles. After 30 min of accelerated cavitation erosion, the mass losses of P-200 and P-170 were 1.7 and 3.6 mg, respectively. These values were 2.1 and 4.5 times higher than that of P-280, respectively. Considering the curing temperature, overall performance, and cavitation resistance of the coating, P-200 was deemed more suitable for application on the surface of light alloy parts. This study provides guidelines for the research and development of PAI coatings based on its investigation of the relationship between the overall and cavitation performances of PAI coatings under different EP contents. |
| Key words: cavitation erosion polyamide-imide epoxy resin mechanical properties fatigue mechanism |
