High-Frequency Induction Heating of Al-Si-Cu-Mg aluminum alloy in Thixoforming

Abstract

Thixoforming is the process of shaping near net shape metal components in a semisolid state. The process consists of preparing feedstock, reheating and shaping. Reheating the billet is the most critical step in thixoforming. Induction heating requires precise temperature control to obtain globular microstructure and prevent process defects, such as insufficient heating, overheating, and electromagnetic end effect and elephant foot phenomena. Moreover, inductive heating parameters are investigated to improve the quality of thixoforming. This study investigates applied coil current and optimal coil geometry and design (i.e. height, diameter and coil turn) in high-frequency induction heating numerically and experimentally. Simulation results combined with an approximation approach method are verified via a reheating experiment. The proposed method validated via an experiment can be a practical tool for predicting temperature distribution and reheating time required for thixoforming.

A Continuous Casting Device with Electromagnetic Stirring for Production of SSM Feedstock Using Al-Si Alloys

“…The major advantage of thixoforming over rheocasting is that the feedstock can be produced separately by conventional casting, stored and transported to the thixoforming station, where it is processed in the following steps: (a) controlled heating from the solid to the semisolid condition at a specific heating rate until the desired thixoforming temperature (and corresponding f l ) is reached; (b) isothermal treatment at the chosen processing temperature for a specific soak time; and (c) pressing/injecting of the semisolid slurry into a mould with the preform (near-net-shape) or form (net-shape) of the final product 6 .…”