Investigation on the effect of pressure die casting process parameters to the plastic forming behavior of sway bar links used in automobiles

Reducing carbon emissions is an important factor in the automotive industry. In addition to providing low weight in many parts used in vehicles, high strength and low cost are required. In line with these requirements, aluminum alloys are preferred compared to other engineering materials. Many automotive parts are manufactured from aluminum-silicon alloys by high pressure die casting (HPDC) method. In order for the parts to have the desired quality and life, it is necessary to know the effects of the process parameters, as well as to design the most suitable mold that will not cause errors such as shrinkage and gas porosity in order to produce successful parts. This master's thesis study was carried out to investigate and eliminate the causes of the breakage problem experienced during the cover closing process in the sway bar links manufactured in AYD Automotive Company within the scope of the KÜSİ program. In this context, the effect of HPDC process parameters on the plastic deformation behavior of the sway bar links used in automobiles produced by the HPDC method was investigated. In the study, first, the most suitable mold design was determined with the support of the Anycasting simulation program for the manufacturing of sway bar links from A356 series AlSi7Mg aluminum alloy. Afterwards, HPDC process was carried out according to Taguchi L9 experimental design table at three different temperature, pressure and velocity parameter levels. The temperatures used in the study were 700, 720 and 740 °C; pressures 850, 1050 and 1290 bar; speeds are 2, 2.5 and 3 m/s. Cover closure processes were performed by placing hinges on the samples manufactured at these parameter levels, and then the usage performance of the sway bar links manufactured by the HPDC process was tested by measuring the capping forces. Afterwards, tensile test rods were prepared from the samples and tensile tests were performed with five repetitions. Thus, the effects of process parameters on yield strength, tensile strength and plastic elongation were investigated. It has been concluded that the parameter with the greatest effect on yield strength from process parameters is pressure and yield strength increase with pressure. There was no breakage problem in any of the 90 cover closing processes. This has shown that the correct mold design and the manufacturing of parts under appropriate process conditions have been carried out.