Determination of Johnson-Cook flow and damage model parameters of Tİ6AL4V alloy produced by powder metallurgy using an analysis program

Flow stress and damage models are mathematical models that define how the material used in simulation programs will respond when deformed at different temperatures and speeds. The JC flow stress and damage model is one of the most commonly used material models in practice. In this research, tensile tests were applied to circular Ti6Al4V alloys with different notch ratios prepared in accordance with the standards in order to obtain model parameters, and stress and strain values were obtained. The samples used were produced as vertical layers by powder metallurgy method and kept in constant temperature stress relief furnaces for two hours to absorb the residual stress and distortion formed in the samples after production. Then, different notch radii were opened on CNC machines for the samples that were removed from the furnace and separated from the tables. The data obtained from the Ti6Al4V alloy samples subjected to uniaxial tensile test in the Instron 8081 hydraulic fatigue device were processed in the FINDJC program. This program was specially written to obtain both the data calculated from the tensile graph and other model parameters by mathematical operations on the strain stress data. As a result of optimization using different regression and curve fitting algorithms, JC flow stress and damage model parameters were obtained. When the obtained parameters were compared with other previous studies, similar results were obtained. In this study, JC flow stress and damage model parameters were obtained using much more economical, simpler test methods and simpler test devices.