# Interplay Between Wear and Thermal Expansion in 6082 Aluminum: A Simulation and Experimental Study
## 3 Results and Discussion
### How Do Wear and Thermal Expansion Influence Temperature  
Wear and thermal expansion influence contact behavior between frictional pairs, impacting interface friction and thereby affecting the frictional dissipation rate. Consequently, the effects of wear and thermal expansion on temperature rise can be analyzed through their impacts on friction and frictional dissipation during sliding.  
Figure 14 compares friction dissipation rates under various operating parameters. Increased load and rotational speed both elevate the friction dissipation rate. Under a low load or speed, the differences in friction dissipation rates are minimal. Under higher loads or speeds, the differences between the three conditions become more pronounced. Initially, the friction dissipation rate, with both wear and thermal effects considered, is similar to scenarios without wear or thermal effects. Over time, the rate decreases compared  
Figure 13: (**a**) Comparison of the wear scar profiles between the experiments and simulations under 15 N and 300 RPM, with and without wear considered. (**b**) Deformation of the pin and disc due to thermal expansion under 15 N and 300 RPM from the FEM result, with wear considered.  
to the other two conditions, and this difference becomes more pronounced as sliding distance increases.  
To further analyze this phenomenon, Figure 15 shows the friction distribution along the disc radius under 15 N and 300 RPM. With only thermal effects considered, friction distribution remains nearly constant during sliding, maintaining a steady friction dissipation rate. When only wear is considered, friction decreases over time while contact area increases, resulting in dynamic competition, which explains the friction dissipation rate fluctuation at 15 N and 300 RPM in Figure 14. With both thermal effects and wear considered, maximum friction is lower compared to scenarios with only wear or thermal effects (Figure 15).  
Figure 14: Frictional dissipation rate under (**a**) different sliding speeds and (**b**) different loads (the results are taken from the simulation).  
Figure 15: Friction distribution along the disc radius under 15 N and 300 RPM, (**a**) considering both wear and thermal effects, (**b**) considering only thermal effects, and (**c**) considering only wear (the results are taken from the simulation).  
Figure 14 compares the friction dissipation rate under various operating parameters. Both increased load and rotating speed elevate the friction dissipation rate. Under a low load or speed, the differences in friction dissipation rates are not significant. However, with a higher load or speed, the differences between the three conditions become more pronounced. Initially, the friction dissipation rate, when considering both wear and thermal effects, is close to the scenarios without wear or without thermal effects. Over time, the rate becomes lower than the other two conditions, and this difference becomes more significant as the sliding distance increases. Additionally, as shown in Figure 5, the contact area decreases when both factors are considered. This reduction in friction and contact area leads to a lower friction dissipation rate compared to the other two scenarios (Figure 14).  
In summary, the combined effects of wear and thermal expansion result in a lower temperature rise than considering each factor alone, as they alter the friction, contact area, and frictional dissipation rates.