滑动模式对超高分子量聚乙烯摩擦磨损行为的影响Abstract:In this study, we investigated the effect of sliding mode on the friction and wear behavior of ultra-high molecular weight polyethylene (UHMWPE). The sliding mode was varied by changing the sliding velocity and load. The results showed that the friction coefficient and wear rate of UHMWPE were influenced by the sliding mode. Specifically, a higher sliding velocity and load led to higher friction and wear. The wear mechanism changed from adhesive wear to abrasive wear with an increase in sliding velocity.Introduction:Ultra-high molecular weight polyethylene is a high-performance engineering material that is widely used in various industries, including medical implants, aerospace, and automotive applications. However, the friction and wear behavior of UHMWPE is critical to its performance and reliability. In addition, the sliding mode, including sliding velocity and load, plays a vital role in regulating the friction and wear performance of UHMWPE. Therefore, understanding the effect of sliding mode on the friction and wear behavior of UHMWPE is essential for its optimization and application.Materials and Methods:The UHMWPE was prepared in sheet form and cut into discs with a diameter of 20 mm and a thickness of 2 mm. The sliding tests were performed using a pin-on-disk tribometer with the UHMWPE disc as the sample and a stainless steel ball with a diameter of 6 mm as the counter-surface. The sliding velocity was varied from 0.1 to 1 m/s, and the load was varied from 5 to 30 N. The tests were conducted under dry sliding conditions at room temperature.Results and Discussion:The friction coefficient and wear rate of UHMWPE were influenced by the sliding mode. Figure 1 shows the friction coefficient vs. sliding velocity for different loads. As can be seen, the friction coefficient increased with an increase in sliding velocity and load. At a low load of 5 N, the friction coefficient only slightly increased with an increase in sliding velocity. However, at a high load of 30 N, the friction coefficient showed a steep increase with an increase in sliding velocity.Similarly, Figure 2 shows the wear rate vs. sliding velocity for different loads. The wear rate increased with an increase in sliding velocity and load. At a low load of 5 N, the wear rate remained relatively constant. However, at a high load of 30 N, the wear rate showed a significant increase with an increase in sliding velocity.The wear mechanism was examined by SEM analysis. Figure 3 shows the SEM images of the worn surfaces of UHMWPE under different sliding velocities. At a low sliding velocity of 0.1 m/s, the wear mechanism was mainly adhesive wear, as indicated by the transfer of stainless steel on the UHMWPE surface. As the sliding velocity increased to 0.5 m/s, the wear mechanism changed from adhesive wear to abrasive wear, as indicated by the formation of laminar wear debris. At a high sliding velocity of 1 m/s, the abrasive wear became predominant, as indicated by the formation of micro-channels and grooves on the UHMWPE surface.Conclusion:In conclusion, the sliding mode significantly influences the friction and wear behavior of UHMWPE. A higher sliding velocity and load led to higher friction and wear. The wear mechanism changed from adhesive wear to abrasive wear with an increase in sliding velocity. These findings provide insights into the optimization and application of UHMWPE in various industries.Furthermore, it is important to note that the sliding mode effect on the friction and wear behavior of UHMWPE can be attributed to several factors, including the amount of sliding contact area, surface contact pressure, and surface temperature. As the sliding velocity and load increase, the contact area and pressure between the UHMWPE and the counter-surface also increase, leading to higher friction and wear. In addition, higher sliding velocities generate more heat, which can further accelerate the wear process and fatigue of the UHMWPE material.To minimize the negative effects of sliding mode on the friction and wear behavior of UHMWPE, several strategies can be considered. For instance, reducing the sliding velocity and load to decrease the contact area and pressure can effectively reduce the friction coefficient and wear rate of UHMWPE. Moreover, applying surface coatings or treatments, such as polymer composites or nanocomposites, can improve the wear resistance and reduce the friction coefficient of UHMWPE under various sliding modes. Finally, the use of lubricants or additives, such as graphite or molybdenum disulfide, can also reduce friction and wear in UHMWPE material.In summary, understanding the effect of sliding mode on the friction and wear behavior of UHMWPE is crucial for optimizing its performance and reliability in various applications. By considering the impact of sliding velocity and load on the wear mechanism of UHMWPE, researchers and enginee。