Die design optimization for axisymmetric hot extrusion of metal matrix composites

✍ Scribed by N.H. Kim; C.G. Kang; B.M. Kim

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 240 KB
• Volume: 43
• Category: Article
• ISSN: 0020-7403
• DOI: 10.1016/s0020-7403(00)00068-0

✦ Synopsis

Strain rate sensitive materials such as Ti alloys, superplastic materials and metal matrix composites (MMCs) can be deformed only in very narrow range of strain rate. In this work, a new process design method for controlling strain rate in workpiece during hot extrusion process is proposed. In this approach, a coupled numerical approach of "nite element analysis and optimization technique to optimal pro"led die which yields more uniform strain rate distribution in the deforming region is applied to the hot extrusion process of MMCs. Extrusion die pro"les are de"ned by Bezier curves, and FPS (#exible polyhedron search) method is used as optimization technique. The change of relative deviation of strain rate, the progressive development of die pro"les with increase of iteration for optimization and the corresponding strain rate distributions are investigated. In addition, the die pro"les by optimization scheme for di!erent extrusion ratios are compared with those by analytical solution.