Formation behavior of continuous graded composition in Ti-ZrO_2 functionally graded materials fabricated by mixed-powder pouring method

摘要

A mixed-powder pouring method has been proposed to fabricate functionally graded materials (FGMs) with the desired compositional gradient. The experimental procedure involves preparation of mixed powders consisting of more than two types of particles with different size and/or density, which exhibit different velocities in suspension and sedimentation to form the green body under gravity conditions. The green body was sintered by a spark plasma sintering (SPS) method. The initiation of the particle settlement was precisely controlled by using crushed ice as the suspension medium. Ti-ZrO_2 FGMs were fabricated, in this study, using different sizes of ZrO_2 and Ti particles. Vickers hardness confirmed the compositional gradient in the fabricated FGMs. A numerical simulation was also carried out to analyze the particle movement inside the suspension medium during the formation process and predict compositional gradient in the FGMs.