HK KamChan Chin WangYing Pio LimWen Chiet Cheong2025-01-022025-01-022016-07-1110.4028/www.scientific.net/KEM.701.177https://dspace-cris.utar.edu.my/handle/123456789/9735In this study, A356 aluminum alloy was heated up to semi-solid state and used as a billet for forward and backward extrusion. The workpiece will undergo solidification at the contact between billet and the tools when the material flowing through the die cavity during the semi-solid extrusion. The plasticity of A356 with 0.3wt% Y at semi-solid state was investigated by performing compression test. A numerical simulation code based on thermo-viscoplastic finite element method was developed to simulate the material flow and study the yttrium-modified A356 aluminum alloy under forward and backward extrusion. A minimum average punch strain rate is proposed for semi-solid extrusion.journal-article