Due to the light weight and electromagnetic interference shielding capabilities in
magnesium alloy material, it is widely utilized in 3C electronic components and automobile parts.
However, its formability is very poor due to the phenomenon of negative strain hardening rate
appearing as the deformation in large strain range, so it is usually formed as die casting or casting
styles leads to much scrap, and manufacturing cost is thus increased. The objective of this study is
to investigate the effect of process parameters on T-shape tube hydro-forming characteristics for
magnesium alloy and it may offer the data resulting from the analysis to predict an acceptable
product of tube fitting for magnesium alloy forming in industry. AZ31 magnesium alloy tube is
used as the billet material for hydro-forming with hydraulic pressure as the main forming power
combined with the mechanical auxiliary force from the punch to fabricate the T-shape tubing
products. Finite element code DEFORM-3D is adopted to investigate the forming states of T-shape
tube forming, by changing process parameters; such as punch velocity, hydraulic pressure, fillet
radius of the die and tool-workpiece interface friction etc. to investigate the material flow of tube
fitting, wall thickness variations, and stress and strain distributions. By qualifying the forming
processes whether if it is completed or not, and synthesizing the overall analysis and judgment, we
establish an admissible level of process parameter range for complete tube manufacture. The results
show that suitable mechanical force can help material flow, prevent large strain deformation falling
into the area of negative strain hardening rate, enhance magnesium alloy to become easy in forming
and make tube fitting to be formed successfully.
Forming and Properties of Friction Stir Welding Process for Dissimilar
Mg Alloy