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While laser-welded preforms provide significant advantages in sheet metal stamping, similar technology has not been developed for forging. In the present paper, the case for solid-state welded preforms in forging is considered and the workability and mechanical properties of selected base metal combinations are analyzed. Results demonstrate that welded preforms have adequate workability based on upsetting and side pressing tests though flow tends to be non-uniform in bi-metal preforms. Tensile tests indicate that the mechanical properties of side pressed preforms are equivalent to those of annealed base metal pieces. While work is ongoing to develop their use, results indicate that friction-welded preforms have potential for use in forging.

This paper describes the development and validation of a Lagrangian-based finite element model for the aluminum extrusion process used to produce thin sections which are characteristic of tubing used in automotive air conditioners. Due to the large reduction involved in producing such tubing, extrusion ratios are between 500 and 2000. In order to study metal flow and establish baseline strains and strain rates in the process, a finite element model based on non-isothermal plane strain deformation was developed. Effective strain rates were predicted to be as high as 1500 s-1 in the weld chamber with effective strains reaching 4.0 in each wall. Billet cooling on the order of 20 °C occurs in the container and portholes of the die while significant adiabatic heating occurs as a result of deformation in the weld chamber.