目的提高Ni-P/nano-WC复合刷镀层的性能。方法利用电刷镀技术将Ni-P与nano-WC粉末共同沉积在40Cr基体表面形成纳米颗粒增强的复合镀层,再利用电接触技术对Ni-P/nano-WC复合镀层进行二次强化。利用光学显微镜、场发射扫描电子显微镜(FES...目的提高Ni-P/nano-WC复合刷镀层的性能。方法利用电刷镀技术将Ni-P与nano-WC粉末共同沉积在40Cr基体表面形成纳米颗粒增强的复合镀层,再利用电接触技术对Ni-P/nano-WC复合镀层进行二次强化。利用光学显微镜、场发射扫描电子显微镜(FESEM)、X射线衍射分析(XRD)、能谱分析(EDS)和显微硬度测量等手段,分析电接触强化处理对Ni-P/nano-WC复合镀层的影响。同时利用滚动摩擦试验分析电接触强化前后复合镀层耐磨性的变化情况。结果电接触强化处理后,Ni-P/nano-WC复合刷镀层的孔隙和裂纹减少,复合镀层与基体之间的界面在高温和高压的作用下发生焊合。XRD分析显示复合镀层的晶粒细化,镀层的晶粒尺寸由35.35 nm下降至26.28 nm。随着接触电流的加大,复合镀层的硬度也在逐步加大。经过20 k A电流的强化,复合镀层平均硬度由637HV0.1增加到885HV0.1,镀层硬度分布更加均匀;4 h的滚动摩损表明,随着接触电流的加大,试样的质量损失逐步减小,经20 k A接触电流强化后的Ni-P/nano-WC复合镀层质量损失为503 mg,比未经电接触强化的Ni-P/nano-WC复合镀层低40%。结论电接触强化技术能有效改善Ni-P/nano-WC复合镀层的微观组织与性能,将镀层界面由机械结合变为冶金结合,同时提高镀层的耐磨性能。展开更多
Nano-ZrO2 and PEEK particles were synergistically filled in unfilled PTFE to improve the wear resistance and maintain a relatively low friction coefficient,and the materials were studied using a reciprocating sliding ...Nano-ZrO2 and PEEK particles were synergistically filled in unfilled PTFE to improve the wear resistance and maintain a relatively low friction coefficient,and the materials were studied using a reciprocating sliding friction and wear tester.In the friction tests,the evolution of various tribological characteristics in both the contact interfaces and debris was observed,and the wear mechanism of the PTFE composites was investigated.The results showed that the wear rate of the PTFE composites synergistically filled with nano-ZrO2 and PEEK was lower and its friction coefficient was slightly higher than that of the unfilled PTFE;the uniformity and continuity of the transfer film generated by the composite with nano-ZrO2 and PEEK were the best,and the particle size of the debris was minimal in comparison to that in other sample systems.展开更多
Polytetrafluoroethylene (PTFE) is a commonly used seal material for oil-free engine that is well known for its excellent tribological properties. In this work, the nano-ZrO2 particles were used as the friction modifie...Polytetrafluoroethylene (PTFE) is a commonly used seal material for oil-free engine that is well known for its excellent tribological properties. In this work, the nano-ZrO2 particles were used as the friction modifiers to improve the friction and wear performance of PTFE-PPS composites. The friction and wear characteristics of PTFE/PPS-nano-ZrO2 composites were investigated by a block-on-ring tester under dry friction sliding condition. The worn surfaces, counterpart transfer films and wear debris were studied by scanning electron microscopy and X-ray photoelectron spectroscopy. It was found that the increase of nano- ZrO2 content could effectively reduce the coefficient of friction and enhance the anti-wear ability of PTFEPPS composites. Especially, the best tribological properties of the composites were obtained when the particle content of nano-ZrO2 was 10 vol%, the anti-wear performance of composite is 195 times better than that of the unfilled PTFE-PPS composite. Under different conditions, the coefficient of friction of PTFE/PPS-nano-ZrO2 composites was more affected by the applied load while the wear rate was more affected by the sliding velocity.展开更多
基金supported by the Technical Project of Guangdong Province, China (Nos. 2020B090923002, 2021A1515011756)GDAS’ Project of Science and Technology Development, China (No. 2021GDASYL20210302006)+3 种基金Sciences Platform Environment and Capacity Building Projects of GDAS, China (No. 2021GDASYL-20210102005)Key R&D Program of Guangdong Province, China (No. 2020B090923002)Guangdong Special Support Program, China (No. 2019BT02C629)Guangdong Basic and Applied Basic Research Fund, China (Nos. 2020A1515111031, 2021A1515010939)。
文摘目的提高Ni-P/nano-WC复合刷镀层的性能。方法利用电刷镀技术将Ni-P与nano-WC粉末共同沉积在40Cr基体表面形成纳米颗粒增强的复合镀层,再利用电接触技术对Ni-P/nano-WC复合镀层进行二次强化。利用光学显微镜、场发射扫描电子显微镜(FESEM)、X射线衍射分析(XRD)、能谱分析(EDS)和显微硬度测量等手段,分析电接触强化处理对Ni-P/nano-WC复合镀层的影响。同时利用滚动摩擦试验分析电接触强化前后复合镀层耐磨性的变化情况。结果电接触强化处理后,Ni-P/nano-WC复合刷镀层的孔隙和裂纹减少,复合镀层与基体之间的界面在高温和高压的作用下发生焊合。XRD分析显示复合镀层的晶粒细化,镀层的晶粒尺寸由35.35 nm下降至26.28 nm。随着接触电流的加大,复合镀层的硬度也在逐步加大。经过20 k A电流的强化,复合镀层平均硬度由637HV0.1增加到885HV0.1,镀层硬度分布更加均匀;4 h的滚动摩损表明,随着接触电流的加大,试样的质量损失逐步减小,经20 k A接触电流强化后的Ni-P/nano-WC复合镀层质量损失为503 mg,比未经电接触强化的Ni-P/nano-WC复合镀层低40%。结论电接触强化技术能有效改善Ni-P/nano-WC复合镀层的微观组织与性能,将镀层界面由机械结合变为冶金结合,同时提高镀层的耐磨性能。
基金Supported by the National Natural Science Foundation of China(No.51165022)Lanzhou Science and Technology Bureau Foundation(No.20122117)the Natural Science Foundation of Gansu Province(No.1310RJZA036).
文摘Nano-ZrO2 and PEEK particles were synergistically filled in unfilled PTFE to improve the wear resistance and maintain a relatively low friction coefficient,and the materials were studied using a reciprocating sliding friction and wear tester.In the friction tests,the evolution of various tribological characteristics in both the contact interfaces and debris was observed,and the wear mechanism of the PTFE composites was investigated.The results showed that the wear rate of the PTFE composites synergistically filled with nano-ZrO2 and PEEK was lower and its friction coefficient was slightly higher than that of the unfilled PTFE;the uniformity and continuity of the transfer film generated by the composite with nano-ZrO2 and PEEK were the best,and the particle size of the debris was minimal in comparison to that in other sample systems.
基金Funded by the National Natural Science Foundation of China(Nos.51165022,51675509)
文摘Polytetrafluoroethylene (PTFE) is a commonly used seal material for oil-free engine that is well known for its excellent tribological properties. In this work, the nano-ZrO2 particles were used as the friction modifiers to improve the friction and wear performance of PTFE-PPS composites. The friction and wear characteristics of PTFE/PPS-nano-ZrO2 composites were investigated by a block-on-ring tester under dry friction sliding condition. The worn surfaces, counterpart transfer films and wear debris were studied by scanning electron microscopy and X-ray photoelectron spectroscopy. It was found that the increase of nano- ZrO2 content could effectively reduce the coefficient of friction and enhance the anti-wear ability of PTFEPPS composites. Especially, the best tribological properties of the composites were obtained when the particle content of nano-ZrO2 was 10 vol%, the anti-wear performance of composite is 195 times better than that of the unfilled PTFE-PPS composite. Under different conditions, the coefficient of friction of PTFE/PPS-nano-ZrO2 composites was more affected by the applied load while the wear rate was more affected by the sliding velocity.
