Processing kinetics and thermomechanical responses of a melt‐infiltrated piezoelectric ceramic composite

Abstract

This paper presents a poro-thermo-piezoelectricity model to investigate infiltration processing of an interpenetrating phase piezoelectric ceramic composite and the thermomechanical responses of the piezoelectric matrix during infiltration by a molten reinforcement phase. Governing equations for fluid-infiltrated porous piezoelectric materials are first formulated based on the theories of thermoporoelasticity and piezoelectricity. Similarity solutions of temperature distribution, infiltration kinetics, pore melt pressure, melt content variation, and stress/strain fields are obtained for infiltration of a porous piezoelectric matrix under one-dimensional strain and flow conditions. Numerical results for infiltration of a long porous PZT bar by a liquid polymer indicate that the infiltration kinetics and pore fluid pressure are similar to those under isothermal processing conditions. The melt content variation in the PZT, however, is dramatically affected by the difference between the inlet melt temperature and initial matrix temperature. A relatively lower inlet melt temperature results in positive melt content variation implying that more melt in the pores of the piezoelectric matrix is available to compensate solidification shrinkage of the molten reinforcement phase thereby reducing the solidification induced microdefects in the composite. The stresses in the piezoelectric matrix during the infiltration are compressive with the magnitudes on the order of the applied inlet melt pressure. The axial strain may become tensile near the inlet when the inlet melt temperature is above the initial matrix temperature.