Fabrication of Al/Al3Te composites by plasma synthesis method

The present work was undertaken to highlight a novel in-situ process in which plasma spraying techniques plus electromagnetic stirring were used to produce Al/Al3Fe composites consist of angular and needle-like morphology of Al3Fe intermetallic compounds of about 10-20 mum in size. The microstructures of fabricated materials consisted of alpha-Al and Al3Fe intermetallic compounds, and the size, volume fraction and shape of Al3Fe intermetallic compounds depended mainly on the temperature of the melt and the plasma spraying conditions such as input current, gas flow rate of plasma and spraying distance. The microstructural difference arose from the difference of instantaneous temperature and velocity of the iron particle on the melt surface. The temperature and velocity of the iron particles in the plasma arc were calculated and the results were compared with the fabricated microstructures. In addition, the evolution of microstructures of angular and needle-like Al3Fe intermetallic compounds was analyzed morphologically by spherical shell model incorporating of diffusion kinetics. (C) 2002 Elsevier Science B.V. All rights reserved.