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目的通过建立双粗糙表面磨削模型,获得微凸体曲率半径对材料磨损的影响大小。方法选取磨具上微凸体与工件上不同变化曲率的微凸体分别建立滑动磨削模型I和模型II,考虑了磨削过程中材料的弹性/塑性变形及其断裂失效,运用有限元方法分析探讨滑动过程相嵌微凸体的应变变化以及磨屑脱离情况。结果磨削滑动过程中,在同等接触干涉量δ=1.30μm条件下,接触角较小的微凸体接触对(θ_1≈19.4°)其上微凸体发生磨损断裂,而接触角较大的微凸体接触对(θ_2≈25.5°)其下微凸体发生磨损断裂。磨损微凸体最大的等效塑性应变量发生在次表层的1.5~2.0μm处。结论双粗糙表面磨削过程中,在其他影响因素相同的情况下,曲率半径较小的微凸体更易形成磨屑。磨损微凸体最大的等效塑性应变量发生在次表层的某一深度处,随着塑性变形的增大,应力三轴度减小,导致材料表层下微观裂纹的萌生形成磨屑。
Aim To establish the double-rough surface grinding model and obtain the influence of the radius of curvature of asperity on the material wear. Methods The asperities on the asperities of the grinding tools and the asperities with varying curvature on the workpiece were selected to establish the sliding grinding model I and model II respectively. The elastic / plastic deformation and fracture failure of the material during the grinding process were considered. By using the finite element method In this paper, the change of strain in asperities of asperities in sliding process and the detachment of wear debris were analyzed. Results In the process of grinding and sliding, asperities contact with the smaller contact angle (θ_1 ≈ 19.4 °) wear and tear asperities at the same contact interference δ = 1.30μm, and the contact angle is larger Asperity contact pairs (θ_2 ≈25.5 °) under the wear asperity rupture. The maximum equivalent plastic strain of wear asperities occurs at 1.5 ~ 2.0μm in the subsurface. Conclusion In the process of double-rough surface grinding, asperities with smaller radius of curvature are more likely to form wear debris under the same conditions of other factors. The maximum equivalent plastic strain of wear asperities occurs at a certain depth of the sub-surface. As the plastic deformation increases, the stress triaxiality decreases, resulting in the initiation of micro-cracks on the surface of the material.