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为了提高聚四氟乙烯(PTFE)的摩擦学性能,采用机械混匀、带温预压及烧结等工艺制备了莫来石和碳纤维填充的PTFE基复合材料,并通过FTIR、XRD、万能材料试验机、洛氏硬度计、DSC及热机械分析分别表征了PTFE基复合材料的显微结构、力学性能和热学性能;然后,使用MRH-3型高速环块磨损试验机测定了复合材料的摩擦系数和磨损率,通过自制的硅油砂浆磨损装置测定了复合材料在不同温度下的耐砂浆磨损性能;最后,借助3D测量激光显微镜研究了复合材料摩擦面形貌,并分析了摩擦磨损机制。结果表明:莫来石和碳纤维在PTFE体系中起到填充增强作用,20wt%莫来石~(-1)0wt%碳纤维/PTFE复合材料的弹性模量由364 MPa增加至874 MPa;20wt%莫来石~(-1)0wt%碳纤维/PTFE复合材料的干摩擦系数较大,但其磨损率与纯PTFE相比降低了3个数量级以上,且此复合材料在水摩擦条件下仍能保持较好的摩擦系数和磨损率,摩擦系数为0.157,磨损率为7.40×10-6 mm3·N~(-1)·m~(-1);此外,20wt%莫来石~(-1)0wt%碳纤维/PTFE复合材料在较高温度下仍能表现出良好的耐砂浆磨损性能。所得结论表明改性得到的PTFE基复合材料的摩擦学性能显著提高,复合材料可用于有杆抽油井防偏磨。
In order to improve the tribological properties of polytetrafluoroethylene (PTFE), mullite and carbon fiber-filled PTFE-based composites were prepared by mechanical mixing, pre-pressing with temperature, sintering and other techniques. FTIR, XRD and universal material testing machine , Rockwell hardness tester, DSC and thermomechanical analysis were used to characterize the microstructure, mechanical properties and thermal properties of the PTFE-based composites respectively. Then, the friction coefficient of the composites was determined by MRH-3 high-speed ring block wear tester Wear rate of the composites were measured by a self-made silicone oil mortar wear device. Finally, the morphology of the tribological surfaces of the composites was studied by 3D measuring laser microscope, and the mechanism of friction and wear was analyzed. The results show that the elastic modulus of mullite and carbon fiber in PTFE system increases from 364 MPa to 874 MPa for 20wt% mullite-1wt% carbon fiber / PTFE composites; 20wt% The dry friction coefficient of stone ~ (-1) 0wt% carbon fiber / PTFE composite is larger, but its wear rate is reduced by more than 3 orders of magnitude compared with that of pure PTFE, and the composite can still maintain better under the condition of water friction The friction coefficient and wear rate are respectively 0.157, and the wear rate is 7.40 × 10-6 mm3 · N ~ (-1) · m ~ (-1). In addition, 20wt% mullite ~ (-1) 0wt% Carbon fiber / PTFE composites still exhibit good mortar wear resistance at higher temperatures. The results obtained show that the tribological properties of the modified PTFE-based composites are significantly improved, and the composite materials can be used for sucker rod sucker rod anti-eccentric wear.