Influence of measurement results of thermal conductivity and heat transfer coefficients on the simulation results of casting process of aircraft engine elements

The paper presents results of tests concerning influence of accuracy in measurements of selected thermal properties of materials of a ceramic mould, insulating mat and an alloy itself on effects of simulation of a casting process provided for elements of an aero-engine. A simulation process was realized by means of the PROCAST program. In initial simulations, thermal parameters were applied and they are accessible in literature and concern materials of a mould and nickel superalloys. Results of simulation revealed presence of numerous defects in a form of gaps, pores and cracks. These results were proved in trial casting. In consequence, it was impossible to select correctly right casting parameters. In order to solve this problem, a value of thermal conductivity was defined experimentally and basing on it, coefficients of heat exchange in metal - mould, mould - insulation mat systems were defined as well. A value of partial coefficients of heat exchange was used to determine values of substitute coefficient of heat exchange for the whole metal - mould, mould - insulation mat systems. By introducing the got data, one managed to define parameters of a casting process, providing improvement in a level of quality of cast elements.