Optimization of Diffusion Bonding of Pure Copper (OFHC) with Stainless Steel 304L

Abstract

This work deals with determination of optimum conditions of direct diffusion bonding welding of austenitic stainlesssteel type AISI 304L with Oxygen Free High Conductivity (OFHC) pure copper grade (C10200) in vacuum atmosphere of (1.5 *10-5 mbr.). Mini tab (response surface) was applied for optimizing the influence of diffusion bonding parameters (temperature, time and applied load) on the bonding joints characteristics and the empirical relationship was evaluated which represents the effect of each parameter of the process. The yield strength of diffusion bonded joint was equal to 153 MPa and the efficiency of joint was equal to 66.5% as compared with hard drawn copper. The diffusion zone reveals high microhardness than copper side due to solid solution phase formation of (CuNi). The failure of bonded joints always occurred on the copper side and fracture surface morphologies are characterized by ductile failure mode with dimple structure. Optimum bonding conditions were observed at temperature of 650 ◦C, duration time of 45 min. and the applied stress of 30 MPa. The maximum depth of diffuse copper in stainless steel side was equal 11.80 µm.

Diffusion Bonding and Transient Liquid Phase (TLP) Bonding of Type 304 and 316 Austenitic Stainless Steel—A Review of Similar and Dissimilar Material Joints

“…Table 7 presents diffusion bonding and TLP bonding parameters of 304 stainless steel with Cu and CuZrCr that may be particularly relevant for parts in nuclear fusion applications. Akbar et al [170] and Yilmaz [171] both present very systematic solid-state diffusion bonding studies of 304 stainless steel with copper. Optimized parameters reported by Yilmaz reach bond strength equivalent to the Cu base material receiving the same heat treatment, determined using both shear testing (bond strength 112 MPa vs. 113 MPa shear strength of the Cu base material) and tensile testing (bond strength 247 MPa vs. 248 MPa UTS of the Cu base material).…”

Effect of Tool Geometry on the Microstructure of Friction Stir Welding of Copper and 316L Stainless Steel

“…The joining of copper and stainless steel can be performed using various processes: electron beam welding, [ 3 ] explosion bonding, [ 4,5 ] spark plasma sintering, [ 6 ] hot isostatic pressing, [ 1,2,7 ] diffusion bonding, [ 8–11 ] or friction stir welding (FSW). [ 12–17 ] All these techniques, except for electron beam welding, belong to solid‐state welding processes.…”