机构地区:[1]中国科学院兰州化学物理研究所固体润滑国家重点实验室,兰州730000 [2]中国科学院大学材料科学与光电技术学院,北京101408
出 处:《中国表面工程》2024年第5期88-101,共14页China Surface Engineering
基 金: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。
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。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
关 键 词:空蚀 聚酰胺酰亚胺 环氧树脂 力学性能 疲劳机理
分 类 号:TQ317[化学工程—高聚物工业]
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