Mechanical properties of stainless steel composites with titanium carbonitride consolidated by spark plasma sintering

Abstract

In this paper, stainless steel-titanium carbonitride-based composites were fabricated and analyzed to utilize for bipolar plate in fuel cells. In order to study the size effect of titanium carbonitride on the mechanical and corrosion resistance properties of the composites, micro and nanosize titanium carbonitride powders were used. Stainless steel-carbonitride composites were prepared by spark plasma sintering and subsequently annealed at different temperatures up to 1100? to improve the morphological and mechanical properties. Various properties of the obtained samples were compared before and after annealing. It was shown that after heat treatment, the mechanical properties of the stainless steel-carbonitride composites improved due to the diffusion of titanium carbonitride particles into stainless steel. Addition of microsized titanium carbonitride powders was found to be effective to improve the mechanical properties, such as microhardness and compressive strength, of the composite. However, addition of nanosized titanium carbonitride powders led to an increase of corrosion resistivity of the composite. Physical properties, such as thermal and chemical stability of the obtained composite samples were investigated by microhardness tester, potentiostat, field emission-scanning electron microscope, EDX and X-ray diffraction.