瓷层厚度影响金瓷界面抗断裂能力的初步研究

Preliminary analysis about influence of porcelain thickness on interfacial crack of PFM

目的 采用云纹干涉法结合界面断裂力学研究瓷厚度对金瓷界面抗断裂能力的影响。方法 比较瓷厚度分别为 0 5mm、1 5mm、2 5mm的试件 (金属均为 0 5mm)界面断裂韧性Jc并观测裂纹扩展。结果 0 5mm组试件的Jc值及承受最大载荷均值 (2 813N/m、9 979N)低于 1 5mm及2 5mm组 (5 395N/m、19 134N与 5 42 9N/m、19 2 5 6N)。 1 5mm与 0 5mm组试件 ,裂纹易沿界面扩展。结论 (1)瓷厚度为 1 5mm与 2 5mm组的金瓷界面抗断裂能力相当 ,厚度为 0 5mm时减弱。(2 )瓷厚度为 1 5mm与 0 5mm组的界面裂纹易沿界面扩展 ,厚度为 2 5mm组易向瓷层内扩展。

Objective This study was about the influence of porcelain thickness on crack at interface.Methods The effect of porcelain thickness on the flaw at the interface between porcelain and metal was studied in three groups with porcelain thickness of 0 5 mm ,1.5 mm and 2.5 mm (metal thickness of 0 5 mm )by means of moire interferometre and interfacial fracture mechanics.The parameter Jc was compared among the three groups and the growing of the flaw was observed.Results Jc and the extreme strength of group with porcelain thickness of 0 5 mm (2 813 N/m and 9 979 N)were lower than those of the groups with porcelain thickness of 1 5 mm and 2 5 mm (5 395 N/m, 19 134 N and 5 429 N/m,19 256 N). Flaws extend along the interface in the groups with porcelain thickness of 1 5 mm and 0 5 mm Conclusions (1) Fracture resistance of the interface in the groups with porcelain thickness of 1 5 mm and 2 5 mm is similar and it decreases in the group with 0 5 mm thick porcelain.(2) When porcelain is 1 5 mm or 0 5 mm thick,flaws will extend along the interface.When porcelain is 2 5 mm thick, flaws will extend into the porcelain layer