A review of the cold roll bonding of alsn alloy/steel bimetal strips

The cold roll bonding (CRB) of aluminium alloys to steel is a key industrial manufacturing process tool used to generate bimetallic composites for engine components. By joining steel and aluminium alloys in the solid state the desired mechanical bearing properties of both metals can be achieved;thus allowing for superior tribological wear and strength characteristics observed in modern automotive bearings. CRB facilitates the joining of dissimilar metals at room temperature making it an economical and industry wide technique. The following work on CRB AlSn alloys to steel offers a critical literature review combined with internal research carried out in collaboration with MAHLE Engine Systems Ltd. MAHLE are a leading automotive bearing manufacturer who have established an effective continuous CRB production line; the only one of its type in the UK. The main process variables involved in CRB AlSn alloys to steel and in particular,what conditions are likely to facilitate the best possible bond strength are discussed. Surface preparation, the role of surface contaminants and oxides, reduction in thickness, friction coefficient, rolling speed and direction, annealing treatments,and suggested mechanisms for CRB are considered in relation to current production practice within MAHLE.