Near net shaping by semi-solid metal processing

Thixoforming- or semi-solid metal processing (SSM) is the shaping of metal components in the semi-solid state. Several companies in Europe, Japan and the US have recently started to manufacture in this way, producing millions of components annually for the motor industry. However, it should be borne in mind that production of all aluminium castings in North America, Europe and Japan is similar to 2 500 000 t, of which thixoforming represents only approximately 1%. Pressure die casting and permanent mould casting are still dominant. One of the hurdles thixoforming has to overcome is the lack of publicly available quantitative data justifying the claim that thixoformed components really are 'near-net shape'. The work in this paper aims to provide such data and show that thixoforming can live up to this claim. This is done by means of a study on the thixoforming of a demonstrator component - an electric motor endplate. The steps taken to produce and assess the quality of this component are described in this paper. (C) 2000 Elsevier Science Ltd. All rights reserved.