Fabrication of Cu/Al2O3/Cu Symmetrical Functionally Graded Material by Spark Plasma Sintering Process

Abstract

Disk-shaped functionally graded materials of copper/alumina system have been fabricated by spark plasma sintering(SPS process. The graded layer consists of symmetrical compositional transition of Cu/Al2O3/Cu, which allows to achieve high heat conduction, electrical insulation and excellent in-plane electrical conductivity. The use of the FGMs as a compliant pad of conduction type of thermoelectric power conversion system offers high thermal energy density through the thermoelectric cell, resulting in the increase of the efficiency of thermoelectric energy conversion. This paper describes the process optimization including densification of metal-ceramic powder mixtures by SPS process, compositionally graded stacking of the mixed powders in a graphite die, the design of the compositional gradient on the basis of one dimensional heat conduction analysis and fabrication of Cu/Al2O3/Cu FGMs according to the predesigned compositional gradient.