Preparation of ZrO₂ (3Y)/SUS (410) Functionally Gradient Plasma Material by Thermal Gradient Sintering

Abstract

Functionally gradient materials (FGM) of ZrO₂(3Y) and SUS(410) were prepared using a spark plasma sintering equipment. Starting powders of SUS and ZrO₂ of 90, 80, 70, 50, 40 and 30vol% were stacked and sintered for 12 min. The temperature was 1200°C at the ZrO₂ layer and 1000°C at the SUS layer. The products were dense and free from pores. The stress due to the thermal expansion mismatch was delocalized by graded structures and no crack appeared. The compressive residual stress acted to stabilize a tetragonal phase of ZrO₂ and lower the fracture toughness of the ZrO₂ layer.