EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

The present study is the state of the art in the thermophysical properties of liquid Al-Ni-based alloys, widely used as functional and structural materials. Manufacturing of simple or complicated parts by different casting processes involve complex interactions between various parameters related to material composition and operating conditions, and often, the manufacture of defect free casting products is almost impossible. Therefore, to prevent formation of casting defects, much attention has been paid to the modelling of solidification. Development of numerical optimization techniques and availability of commercial software packages together with new generation of powerful supercomputers and accurate property data are needed for engineering design of materials by controlling composition and microstructure. However, the use of such mathematical and numerical tools for the modelling of solidification is often limited by the lack or paucity of reliable thermophysical properties data, such as surface tension and density, thermal conductivity, diffusivity and viscosity of relevant liquid metals and alloys, needed as input parameters for the computational models. Indeed, the high reactivity of Ni-based superalloys, together with impossibility to find chemically inert crucible or support materials to avoid the reactions at the interface, is the main problem when deal with conventional experiments. In order to overcome these limitations, in the framework of the ESA-MAP Thermolab and Thermoprop projects, the containerless processing using non-contact diagnostic tools has been applied reducing the interactions between the melt and its environment. Practical benefits of containerless processing include suppression of heterogeneous nucleation enhancing undercooling of the melt and making it possible to achieve isothermal solidification near its liquidus or much lower temperatures. In this work, the thermophysical properties data of Ni-based industrial alloys are collected and compared to the corresponding model predicted values.