Preparing Magnetocaloric LaFeSi Uniform Microstructures by Spark Plasma Sintering

Autor: Henrique Neves Bez, Cristiano S. Teixeira, Izabel Fernanda Machado, N. Vicente, Paulo A.P. Wendhausen, J. Ocanã
Rok vydání: 2014
Předmět:
Zdroj: Materials Science Forum. 802:491-495
ISSN: 1662-9752
Popis: Spark Plasma Sintering (SPS) of LaFeSi alloy powders was conducted to prepare magnetocaloric La-Fe-Si-based uniform microstructures. Two electrically insulating discs made of alumina were interposed between the punches and powder sample inhibiting the flow of electric current across the powder. This approaching aiming at improving the sample temperature distribution by deviating the electric current throughout the graphite die, since the electric current induces overheating byin situJoule effect on powder. The LaFeSi powder with particles under 150 µm was obtained by mechanical milling of particles from hydrogenated and decrypted casting ingot. The characterizations of sintered samples were performed by Scanning Electron Microscopy (SEM), Archimedes principle, Vicker’s hardness and microhardness. The uniformity of the microstructure was evaluated by checking the evidence of position on the Vicker’s microhardness by means of ANOVA statistics.
Databáze: OpenAIRE