Characterization of Fly Ash and Its Reinforcement Effect on Metal Matrix Composites: a Review

摘要

The widespread adoption of particulate reinforced metal matrix composites (MMCs) for specific engineering applications has been restricted due to their high cost of productions. The distribution and orientations of the reinforcement particles in the matrix alloy is influenced by several factors. Rheological behaviour of the matrix melts, the particle incorporation method, interactions of the particles and the matrix before, during and after the mixing, and the changing particle distribution during solidification are considering as major area of concern. Fly ash is also known as alumina-silicate particles, has been incorporated in to metal matrix composites for the last few decades mainly to reduced their weight, manufacturing cost and enhancing selected properties. This paper represents an overview of the morphology and composition of both cenosphere (hollow) and precipitator (solid) fly ash particles of different sizes. The effects of various fly ash reinforcement on microstructure and mechanical properties, tribological behaviour and thermodynamic characteristics of different matrix of metallic alloy through highlighting their merits and demerits have been reviewed rigorously. Effects of volume fraction, particle size on the mechanical properties like hardness, tensile strength, strain, wear and fatigue is discussed in detail. Major occurrence like agglomerating phenomenon, formation and distribution of in situ Mg₂Si, MgAl₂O₄ and MgO into the metallic matrix, filler-matrix bonding and phase transition are discussed in this article.