Research on development of evaluation technique for wear of ceramic coated materials

(1)磨损机理的数值模拟为分析陶瓷涂层材料在滚动-滑动接触过程中的变形，采用循环塑性本构方程进行了计算机模拟。(2)陶瓷涂层材料的磨损试验通过对陶瓷涂层材料在销盘磨损试验机上的磨损试验发现，陶瓷涂层材料的磨损寿命明显延长，陶瓷涂层材料的磨损寿命评估与涂层剥离寿命的评估相一致。此外，涂层工艺条件对耐磨性的影响在评价中也是重要的。(3)计算机模拟与磨损预测的关系。与接触表面的粘着磨损相比，材料中的疲劳磨损更为显著，因为涂层保护了接触表面。然后考虑了由计算机仿真得到的基材的力学状态与实际磨损现象之间的关系。首先，进行了衬底材料多轴状态下的低周疲劳试验，明确了材料的疲劳寿命与材料所受塑性功密度密切相关。将计算机模拟和疲劳试验计算的磨损寿命预测值与相同条件下的磨损试验结果进行了比较，结果表明与材料的磨损寿命吻合较好。

(1) Numerical simulation of wear mechanismTo analyze the deformation of ceramic coated materials during rolling-sliding contact, the computer simulation using the constitutive equation for cyclic plasticity was conducted. The result shows that there is the significant discontinuity of stresses and strains on the interface of coating layrs and substrates, and that would cause the delamination of coating layrs which is considered to be the wear life limit of the ceramic coated material.(2) Wear test of ceramic coated materialFrom the wear test of ceramic coated materials using a pin-on-dick wear machine, it is found that the ceramic coating makes the life of materials against wear apparently longer and the evaluation of wear life for ceramic coated materials corresponds to the evaluation of delamination of coating layrs. Moreover, the effect of the conditions in coating process on the wear resistance is also important in the evalualions.(3) Relation between computer simulation and wear predictionThe fatigue wear in the materials is more significant comparing to adhesive wear on the contact surface because coating layrs protect the contact surface. Then the relationship between mechanical states of substrate, which is obtained from the computer simulation, and actual wear phenomenon was considered. At first, the low cycle fatigue tests of substrate materials in multi axial state were conducted and it was clarified that the fatigue life of the material is closely related to the density of the plastic work which the materials are subjected to. Then the wear life prediction calculated from the computer simulation and the fatigue tests was compared with the result from the wear test under the same conditions as calculation, and these results showed a good agreement with the wear life of the materials.