ZrO_2/Ni FGM中微观残余热应力分析

Analyses of Residual Thermal Microstresses of ZrO_2/Ni FGM

陶瓷-金属FGM成分沿厚度方向变化,微观残余热应力分析对确定FGM材料体系极为重要。按球对称模型采用弹性理论进行分析,确定了微观残余热应力与陶瓷和金属相的弹性性能、在FGM中的位置的关系。结果表明,微观应力具有短程分布特点,并且在同一梯度层内最大微观应力处于相界面处。同时,通过对ZrO2/NiFGM制备过程中的陶瓷-金属界面应力的分析表明,FGM制备过程中可能在基体中产生大量微裂纹。

The FGM is taken to be a ceramic - metal composite with its component changing with position in the FGM along with the thickness direction. The residual thermal microstresses analysis is important to determine the material system of FGM. Based on an elastic mechanics analysis according to a spherical symmetric model, the residual thermal microstresses are determined as a function of the elastic properties of the ceramic and metal phases, and the location. The results show that the residual microstresses have a characteristic of short - range distribution. And the maximal stresses locate in the interface of ceramic and metal phases at every graded layer. In the end, the residual thermal stresses of ceramic-metal interfaces in ZrO2/Ni FGM cooled to room temperature after sintering have been analyzed. The results show that many microcracks would likely develop in the matrix of FGM.