Semi-Solid Extrusion of Complex-Shaped Steel Rods Using Ceramic Dies

Abstract

Isothermal semi-solid extrusion experiments using steel grade X210CrW12 as work material were performed on an industrial forging machine. An improved and up-scaled tool design was applied, based on the concept of self-heating ceramic dies tested in previous laboratory-scale studies and allowing for die preheating temperatures of up to 1400°C. Steel rods of complex cross sectional geometry were formed at low extrusion forces. Shape accuracy of as-formed rods is accurate and metallurgical examination yields no evidence of liquid phase separation. With a view on the intended industrial implementation construction of ceramic tools has to be improved in order to avoid rupture of ceramic parts due to thermo-mechanically induced stresses and to benefit from the advantages inherent to ceramics in metal forming.

Obtenção de espumas sintaticas da liga AA2011 a partir do metal no estado semi-solido e sua caracterização metalurgica

“…Diminuição do custo de ferramental: menor temperatura de trabalho significa maior vida útil das ferramentas e possibilidade de utilização de moldes alternativos, na tixofundição (MUENSTERMANN, 2008;SILVA, 2004); Melhoria na qualidade do processo: produtos com geometria complexa, de paredes mais finas, e menor número de etapas de conformação (near net shape) são típicos de processos de tixoconformação; precisão dimensional e propriedades mecânicas superiores aos produtos obtidos pela fundição convencional podem ser obtidos (ATKINSON, 2004).…”