In order to develop alloys with high temperature capabilities, it is very important to develop computer programs for designing alloys to avoid inefficient trial and error experiments. Our research group firstly developed an alloy design program (ADP) for the prediction of some mechanical properties of Ni-base superalloys. ADP is based on regression analysis of experimental data accumulated, and by inputting the composition of the designed alloys, information such as g / g' equilibrium composition, solvus / solidus temperatures, creep rupture life at 1040oC at 137 MPa and corrosion resistance can be obtain. As a more fundamental approach, we have been applying the cluster variation method (CVM) to Ni-base superalloys and precious metal group PGM- based refractory superalloys. This method employs Lennard-Jones pair potentials, and allows the equilibrium phase chemistries, volume fractions and lattice parameters to be estimated as a function of alloy composition, temperature and pressure.
It is also important to understand the temporal and spatial evolution of the atomic arrangement in materials. A Monte Calro simulation (MCS) has been employed to obtain such information in Ni-base superalloys.
Currently, we have started to conduct molecular dinamics (MD) to predict the movement of individual atoms in Ni-base alloys.
These numerical methods will be combined to bring useful information in designing new materials.