An engine hood of magnesium wrought alloys made by tempered sheet hydroforming with hydroforming fluids - state of the art in research

This paper is focused on lightweight construction potential of magnesium wrought alloyed sheets. Apart form the mechanical and technological material characteristics, component design and dimensioning of the tempered performing and hydroforming tools are emphasized. Furthermore, conceptual design, building and tryout of an appropriate tempered hydroforming press are taken into consideration. Nevertheless, the paper investigates how a pattern bonnet of magnesium wrought alloys is formed within a tempered hydroforming procedure supported by hydroforming fluids up to a maximum temperature of 300 °C at a maximum inner pressure of 800 bar. Formability of materials, which are difficult to form, also including magnesium alloys, can be extended very much due to an increase in temperature during the forming procedure. In addition to the expansion of the forming range as a result of the influence of temperature, yield stress is decreasing at the same time. This effect makes lower forming forces necessary, which results in lower presses