The Effects of the Heating Conditions on the Hydro-Formability of the Aluminum Alloys at High Temperatures

Abstract

Modern automobiles are built with a steadily increasing variety of materials and semifinished products. The traditional composition of steel sheet and cast iron is being replaced with other materials such as aluminum and magnesium. But low formability of these materials has prevented the application of the automotive components. The formability can be enhanced by conducting the warm hydroforming using induction heating device which can raise the temperature of the specimen very quickly. The specimen applied to the test is AA6061 extruded tubes which belong to the age-hardenable aluminum alloys. But in the case of AA6061 age hardening occurs at room temperature or at elevated temperatures before and after the forming process. In this study the effects of the heating condition such as heating time, preset temperature, holding time during die closing and forming time on the hydroformability are analyzed to evaluate the phenomena such as dynamic strain hardening and ageing hardening at high temperatures after the hydroforming process.

Finite element analysis and experimental confirmation of warm hydroforming process for aluminum alloy

“…When the preset temperature is reached, the coil is removed and the upper die closes on the tube. At that point in time and before the warm hydroforming begins, the tube temperature decreases, due to natural convection of the surrounding air and conduction into the punches which are used to prevent oil leakage [5,6]. Fig.…”

Residual Stress Relief and Redistribution of Welded Metals by Vibratory Stress Relaxation

“…Several methods in order to cause the residual stress relaxation such as annealing and mechanical treatment [1] have been applied to the structural components. However, in order to treat large component in the shipbuilding industries and prevent the mechanical properties from being aggravated due to annealing, vibratory methods has been suggested as residual stress relief process.…”