【摘要】 采用Deform-3D软件对相对密度为90%的Fe-2Cu-0.6C粉末冶金齿轮表面滚压过程进行有限元模拟,研究滚压过程中齿轮应力应变和相对密度的分布及变化规律,并利用标准渐开线齿形的工具轮进行齿轮坯料滚压实验来验证有限元模拟结果。模拟结果表明,轮齿两侧面的等效应变分布存在差异,进入滚压面的最大等效应变出现在分度圆附近,退出滚压面的最大等效应变出现在齿顶。齿面上的等效应力随滚压圈数增加而快速增大,并逐渐趋于稳定。齿面表层相对密度的提高可分为3个阶段,分别为孔隙快速压实阶段、密度缓慢增长阶段与密度稳定阶段。工具轮完成0.6 mm的进给后,轮齿表面到心部的相对密度呈梯度分布,表面形成大约0.3~0.5 mm厚度的致密层(相对密度≥98%)。实验结果与模拟结果具有较好的一致性,验证了有限元模型的可靠性。更多还原

【Abstract】 A Three-dimensional finite element model was used to analyze the surface densification of Fe-2Cu-0.6C P/M gears during a rolling process. The distributions of effective strain, effective stress and relative density of the sample during rolling process were obtained. The rolling experiment was conducted using a standard spur tool gear to verify the accuracy of finite element analysis. The simulation results show differences of the effective strain distributions on two opposite flanks of a tooth. On the approach side, the maximum strain occurs near pitch circle while on the trail side the maximum strain is found at tooth tip. The effective stress increases fast at initial rolling process and tends to steady with the number of rolling cycles increasing. The density increasing process of gear tooth could be divided into three stages: fast increasing, slowly increasing and remaining stability. After rolling progress, there exists density distribution gradient with a densified layer about 0.3~0.5 mm at the tooth surface. The experiment results are in better agree with simulation ones, which verified the accuracy of finite element analysis.更多还原