【摘要】 采用有限元数值计算方法,模拟分析了TiN、Si3N4的双层涂层与GCr15基体体系中的最大剪应力分布.结果表明,将低弹性模量的Si3N4用作表面涂层时,整个涂层体系的力学性能较佳;对于涂层总厚度为0.2a(a为赫兹接触半宽)的Si3N4/TiN/基体涂层体系,相对厚度系数越大,基体内的最大剪应力分布越趋向于表面;相对厚度系数对基体内和涂层/涂层交界面上的最大剪应力分布没有显著影响;涂层/涂层和涂层/基体交界面上的最大剪应力分布在沿水平方向偏离接触中心点a左右的地方出现最大值,此处较易萌生裂纹.更多还原

【Abstract】 FEM analysis of the distributions of maximum shear stress in coating system with TiN/Si 3 N 4 double coating layers indicated that the distribution of maximum shear stress is better if the material with relatively low Young’s modulus used as the surface layer.In the case that the total thickness of two coat-ing layers is0.2a(a—the half Hertzian contact width),the location of maximum static stress that located in substrate become nearer to surface progressively as the relative thickness factor is greater.The effect of relative thickness factor on the maximum shear stress at the coating/coating interface and the coating/sub-strate interface is negligible.Also,it was suggested that the peaks of the maximum shear stresses at both coating/coating and coating/substrate interfaces reach the highest values at points horizontally deviating by about a from the contact center,where the initial cracks will occur.更多还原