Integrated manufacturing of REciclable multi-material COmposites for the TRANSport sector
Ni Porous Preforms Compacted with Al2O3 Particles and Al Binding Agent
This work presents an energy-efficient, cheap, and rapid production method of a metal–ceramic preform with open porosity suitable for liquid metal infiltration and filtration applications. It is based on cold isostatic pressing of a mixture of relatively hard Ni and Al2O3 powders with the addition of small amount of Al powders, acting as a binding agent. Open porosity is primarily controlled by Al2O3 particles partially separating Ni particles from mutual contacts. Cold isostatic pressed green compacts were subjected to thermal oxidation by heating in air to 600 °C, 700 °C, and 800 °C. The weight gain and open porosity of oxidized compacts were examined. The chemical composition and microstructure were analyzed by SEM-EDS and XRD techniques. The stability of preforms and the effect of thermal cycling on the open porosity were tested by thermal cycling in an inert Ar atmosphere in the temperature range up to 800 °C. It appeared that, in addition to NiO being an expected product of oxidation, Ni aluminides and spinel particles also played an important role in inter-particle bonding formation. Ni-NiO porous composites resist chemical corrosion and exhibit structural and chemical stability at higher temperatures and admixed Al2O3 particles do not deteriorate them. After subsequent infiltration with Al, it can offer a lower density than other materials, which could result in lower energy consumption, which is highly needed in industries such as the automotive industry.
» Author: Andrej Opálek
» Reference: doi: 10.3390/ma16030988
» Publication Date: 20/01/2023
This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement Nº 768737
