Adiabatic self-heating determination for Ti6Al4V at different temperatures

摘要: Nowadays, predictive models are one of the most widely used techniques to predict material performance subjected to different manufacturing processes. However, to carry out accurate predictions, these models require reliable input data which are obtained from thermomechanical tests. Nevertheless, the majority of the work employed during plastic deformation is transformed into heat. This heat is dissipated to the surroundings and just a small amount is stored in the deformed sample, making the temperature of the sample to change during the test. In this context, the adiabatic heating, that could be defined as the ratio between the heat spent to heat the sample to the plastic work is a key parameter. This parameter is commonly taken as 0.9 and it is usually used by commercial finite element software. However, many authors took a different approach, defining the adiabatic heating as the ratio between the heat experimentally measured to the total plastic work. This second approach is neglecting heat losses and could lead to an underestimation of this coefficient. In addition, both approaches are used indistinctly which could lead to misunderstandings. Thus, the aim of this paper is to measure the adiabatic heating coefficient for Ti6Al4V sample being deformed using a Gleeble thermomechanical simulator. A 3D thermodynamic analysis was carried out, taking into account heat losses by different sources such as radiation, convection, conduction or mass fluxes.