Creation of Fine and Spherical Magnesium Crystals via Control of Nucleation and Growth Instabilities

摘要: Microstructures are at the centre of materials science and engineering. The creation a new microstructure implies material therefore potential applications. Solidification is one most economic versatile formation processes for metallic materials. One central tasks solidification control to achieve fine, uniform equiaxed non-dendritic grain structures. This often attained through effective inoculation or refinement in commercial production. work discusses spherical grains crystals nucleation growth instabilities. particular interest semisolid metal processing. Through more than three decades development, (SSM) processing has been established as commercially useful manufacturing route production near-net shape components high integrity performance. key process obtain slurry free dendrites, with solid being present non-agglomerated, fine particles, minimum entrapped liquid [1, 2]. Such slurries obtainable by number approaches [3], notably direct indirect agitation, partial remelting feedstock that possesses structure, which can be obtained recrystallisation, refinement, spray casting low superheat some cases. It desirable able produce primary directly from state without agitation. In addition, an as-cast structure will provide further opportunities improve structural uniformity compared equaixed same size. purpose this demonstrate, both theoretically experimentally, magnesium state, simply either when melt cast superheated state. Historically, chemical tried [4]. However, these efforts have limited attaining billet, followed reheating billet thixo-formable [5]. These not routes, only plays intermediate supplementary role.