Solid state bonding of porous nickel electrode to AISI 304 austenitic stainless steel

Abstract Diffusion bonding between porous nickel mesh and stainless steel rings has been carried out in the temperature range of 700–900°C under uniaxial pressure. The specimens have been joined directly and also using Ni as an interlayer. The microstructure of the diffusion-bonded joints has been characterised by optical microscopy, scanning electron microscopy (SEM), and electron probe microanalysis (EPMA). The concentration profiles are smooth and do not show the formation of any intermetallic compound. The Boltzmann–Matano method has been used to evaluate the effective interdiffusion coefficients. The interdiffusion coefficients are of the order of 10-15 m2s-1 and these values increase with increase in Ni concentration. The microhardness values near the diffusion zone vary in the range of 185–265 HV(50 g). The specimens bonded at optimised conditions, indicate that the shear strength is superior to the parent porous nickel.