Mold Modeling and Optimization of Metallic Tension Bar in AA 7075 Aluminium Alloy Casting

In this paper, the design and application of permanent mold casting technology reserving a significant place in the light alloy casting technology was conducted due to its convenience for mass production and industrial need. The metal tensile bar mold design, mold preheat temperature (100°C-150°C-200°C), thermal stress, fatigue and damage analyses were examined to be used in the casting experiments by using the finite element analysis. As well as the casting temperature and solidification time, the material flow analyses were conducted by using a computer-aided program. By producing the mold following the modeling and analyses studies, AA7075 aluminum alloy was melted at 800°C and casted in the permanent mold. Following the casting procedure, the tensile bars of aluminum alloys were prepared in conformity with the standards and their tensile and hardness tests were conducted. The general and fracture surface microstructure differences of experiment specimens were examined. As a result of modeling and analysis studies made in the computer environment, the surface stresses of specimen and runner regions which were significant in the mold design were calculated at 100, 150 and 200°C preheating temperatures. The most convenient mold lifetime was calculated by making fatigue calculations for permanent mold at 800°C. DOI: http://dx.doi.org/10.5755/j01.mech.24.4.19752