There is currently great interest in the process of diffusion bonding. The main thrust has been in the joining of advanced materials such as superplastic alloys, metal matrix composites and ceramics and, most importantly, to introduce the process into mass-production operations. Diffusion bonding has also led to reduced manufacturing costs and weight savings in conventional materials and developments in hot isostatic pressing have allowed greater design flexibility. Since the first conference on Diffusion Bonding, held at Cranfield in 1987, considerable advances have been made and it was therefore considered appropriate to organise the Second International Conference on Diffusion Bonding which was held at Cranfield Institute of Technology on 28 and 29 March 1990. The meeting provided a forum for the presentation and discussion of recent developments in Diffusion Bonding and was divided into four main subject areas: steel bonding and quality control, diffusion bonding of aluminium alloys, bonding of high temperature materials and general applications. This structure is retained in the proceedings. DAVID STEPHENSON vii CONTENTS v Preface ......................... .