二硫化钼的粒径对聚氨酯复合材料摩擦学性能的影响  

Effect of Particle Size of MoS_(2) on Tribological Properties of TPU-based Composite

作　　者：郑占模 董从林[1,2,3] 袁成清 张湘军[4] 白秀琴 吴宇航[1,2,3] ZHENG Zhan-mo;DONG Cong-lin;YUAN Cheng-qing;ZHANG Xiang-jun;BAI Xiu-qin;WU Yu-hang(School of Naval Architecture,Ocean and Energy Power Engineering,Wuhan University of Technology,Wuhan 430063,China;School of Transportation and Logistics Engineering,Wuhan University of Technology,Wuhan 430063,China;Reliability Engineering Institute,National Engineering Research Center for Water Transportation Safety,Wuhan 430063,China;China Classification Society Wuhan Branch,Wuhan 430063,China)

机构地区：[1]武汉理工大学船海与能源动力工程学,武汉430063 [2]武汉理工大学交通与物流工程学院,武汉430063 [3]国家水运安全工程技术研究中心可靠性工程研究所,武汉430063 [4]中国船级社武汉分社,武汉430063

出　　处：《表面技术》2023年第8期161-172,共12页Surface Technology

基　　金：国家自然科学基金面上基金项目(52075399);工信部高技术船舶专项(工信部装函[2019]358)。

摘　　要：目的研究二硫化钼(MoS_(2))颗粒粒径对热塑性聚氨酯(TPU)高分子材料的自润滑性能和耐磨性能的影响规律,提升TPU的摩擦学性能。方法选用4种不同粒径(50、500 nm和5、50μm)的MoS_(2)颗粒,通过物理共混的方式制备新型MoS_(2)/TPU复合材料,基于RTEC多功能摩擦磨损实验机,开展水润滑条件下的摩擦磨损试验。通过分析比较改性TPU的力学性能、摩擦系数、磨痕轮廓、表面形貌及其摩擦副接触面的元素组成与分布情况,揭示MoS_(2)不同粒径尺寸对TPU的摩擦磨损机理的影响机制。结果MoS_(2)虽然削弱了TPU的部分力学性能,但摩擦过程中形成的MoS_(2)润滑膜有效降低了TPU的摩擦系数和磨损程度。改性TPU的拉伸强度和断裂伸长率随着MoS_(2)粒径减小呈现先增高、后降低的趋势。500 nm MoS_(2)改性的TPU拉伸强度和断裂伸长率最大,分别为33.80 MPa和334.55%。改性TPU的平均摩擦系数和体积行程磨损率均随着MoS_(2)粒径的减小呈现先降低、后增高的趋势,500 nm MoS_(2)改性TPU的平均摩擦系数和体积行程磨损率最小,当载荷为40 N时分别降低了58.1%和97.8%。长时的摩擦磨损试验表明,Al_(2)O_(3)陶瓷球与500 nm MoS_(2)改性的TPU磨损之后的表面S、Mo元素质量分数之和最高,为34.95%,说明小粒径MoS_(2)更加有利于持续转移并稳定吸附在磨损表面。结论适当粒径MoS_(2)有利于磨损界面MoS_(2)润滑膜的形成和抑制TPU力学性能的削弱,降低改性TPU摩擦系数和磨损量。该研究可为设计具有优异低摩擦、耐磨损性能的新型水润滑轴承复合材料提供参考。The work aims to study the laws of impact that molybdenum disulfide(MoS_(2))particle size has on the self-lubricating and wear resistance of thermoplastic polyurethane(TPU)polymer materials,and to improve the tribological properties of TPU.For these purposes,a new TPU matrix composite composed of TPU and four different sizes(50 nm,500 nm,5μm,50μm)of MoS_(2) particles was fabricated by physical blending.The RTEC wear test apparatus was used to test the tribological properties of modified TPU composites under water-lubricated conditions in low friction velocity and heavy load.The mechanism through which the effect of different particle sizes of molybdenum disulfide on friction and wear mechanism of modified TPU composite was revealed by analyzing the typical mechanical properties,coefficient of friction(COF),wear morphology,wear rate and element composition and distribution on the wear interface of the friction pairs.The results showed that the MoS_(2) tribo-film formed during the friction process effectively reduced the COF and TPU deformations on wear surface although the mechanical properties of the TPU were weakened by MoS_(2).The tensile strength of the modified TPU composites increased firstly and then decreased with the declining of MoS_(2) particle size and TPU modified by 500 nm MoS_(2) exhibited the highest values of 33.8 MPa.The similar trend could be seen in the elongation at break of modified TPU composites and the elongation at break of TPU modified by 500 nm MoS_(2) was the highest,approximately 334.55%.The average COF and volume stroke wear rate of the modified TPU composites decreased earlier and later increased with the reduction of MoS_(2) particle size and TPU modified by 500 nm MoS_(2) presented the lowest average COF and wear rate of 0.093 and 0.12×10-3mm3/(N m)respectively,which were reduced by 58.1%and 97.8%respectively in 40 N compared with pure TPU.Furthermore,the results of longtime wear test under the same conditions showed that the COF curve of TPU modified by 500 nm MoS_(2) always m

关 键 词：MoS_(2) 热塑性聚氨酯 颗粒尺寸 力学性能 摩擦学性能 

分 类 号：TH117[机械工程—机械设计及理论]