A PROCESS MODEL FOR THE FRICTION WELDING OF AL-MG-SI ALLOYS AND AL-SIC METAL-MATRIX COMPOSITES .1. HAZ TEMPERATURE AND STRAIN-RATE DISTRIBUTION

The present investigation is concerned with the development of an over all process model for the microstructure and strength evolution during continuous drive friction welding of Al-Mg-Si alloys and Al-SiC metal matrix composites. In Part I the different components of the model ar e outlined and analytical solutions presented which provide quantitati ve information about the HAZ temperature distribution for a wide range of operational conditions. Moreover, a general procedure for modellin g the HAZ strain mte distribution has been developed by introducing a series of kinematically admissible velocity equations which describe t he material flow fields in the radial, the rotational, and the axial d irection, respectively. Calculations performed for both types of mater ials show that the effective strain mte may exceed 1000 s-1 in positio ns close to the contact section due to the high rotational velocities involved. Application of the model for evaluation of the response of A l-Mg-Si alloys and Al-SiC metal matrix composites to the imposed heati ng and plastic deformation is described in an accompanying paper (Part II).