Combustion synthesis and characterization of porous Ni-Al materials for metal-supported solid oxide fuel cells application

Abstract

Combustion synthesis (CS) in thermal explosion mode under conditions of controlled heat loss is used for synthesis of thin Ni-Al porous plates. In the present work, compacted Ni-Al elemental powder mixtures placed between heat-removing clamp plates are heated in a furnace at 25 K/min up to 1000 K under the uniaxial load up to 1.2 MPa with further heat treatment at the temperature of 1100 K. The effects of the Ni/Al mass ratio, reagent powders size, porosity and thickness of the reacting samples as well as conditions of heat-exchange during the CS on the reaction parameters have been studied. Based on the thermocouple measurements, the temperature and timing characteristics of the CS process have been calculated. The phase composition evolution during the process has been analyzed using X-ray diffraction and energy-dispersive X-ray spectroscopy. Special attention has been paid to the study of the following characteristics of synthesized materials: porosity parameters, gas permeability and mechanical properties. Due to the high strength of synthesized materials and formation of relatively homogenous structure with proper pores size and gas permeability, the synthesized porous Ni-Al plates can be considered as good supporting substrate for application in metal-supported solid oxide fuel cells.