DIFFUSION BOND]NG OF STEEL TO ENHANCED PRODUCT WITY

Abstract

Diffusion bonding has been gaining greater attention in the fabrication of bonded joints of similar and dissimilar materials in aerospace and nuclear industries. Here in this study diffusion bonding of low carbon steel is done by conventional method, with the use of silver interlayer and by impulse diffusion bonding technique with silver interlayer. The process parameter is chosen approximately for conventional diffusion bonding with and without silver interlayer and design of experiment method is used to get optimum value of process parameters for impulse diffusion bonding. In order to determine the strength of the joint tensile test, tensile shear test and micro hardness were performed. Additionally optical microscope, scanning electron microscope and energy dispersive spectrometry elemental analysis is done to analyse the interface. X-ray diffraction technique is used to check the compound formed at interface with silver interlayer. The highest tensile strength achieved in conventional diffusion bonding technique without interlayer is 440 MPa at 825 °C, 12 MPa and 75 mm. bonding time. The highest tensile shear strength in impulse diffusion bonding is 90.9 MPa at 875 °C, 14 MPa and 10 no of pulses. The optimum value of parameters for impulse diffusion bonding is 875 °C, 10 MPa and 10 no of pulses. By EDX analysis it is clear that there is no significant diffusion of silver on either side of the interface.