Grain refinement of Mg-alloys by native MgO particles: An overview

Grain Refinement Mechanisms of TiC0.5N0.5 Nanoparticles in Aluminum

“…Microstructure control is of particular importance in the metal casting industry, and it is often the case that a uniformly fined, equiaxed grain structure is favorable for both cast and wrought alloys, as it benefits the casting process and improves the mechanical properties of the cast metal, facilitating subsequent mechanical working [ 1 , 2 , 3 ]. Grain refinement by inoculation is a well-established practice, which is usually accompanied by the addition of a grain refiner to the metallic melt [ 4 , 5 ]. For effective grain refinement, not only do the nucleants in the grain refiner need to provide potent heterogeneous sites for nucleation of the primary solid phase, but also some solute elements are required in the melt to restrict the grain growth and facilitate nucleation, either at a columnar front competing with equiaxed solidification or from particles where nucleation has already occurred [ 6 , 7 , 8 ].…”

Segregation of Alkaline Earth Atoms Affects Prenucleation at L-Al/γ-Alumina Interfaces

“…Solid particles in liquids reduce the barrier of nucleation and catalyze the phase transition from liquid to solid, which is referred to as heterogeneous nucleation [1][2][3]. Heterogeneous nucleation, thus, occurs most often, while homogeneous nucleation in liquid without heterogeneous particles happens rarely [3,4]. Heterogeneous nucleation is determined by the potency of the substrate to the metal.…”

“…Heterogeneous nucleation is determined by the potency of the substrate to the metal. The more potent the substrate, the less driving force is required [3][4][5]. In metallurgy, the foreign particles are referred to as grain refiners.…”

“…In order to obtain cast parts and metals/alloys of fine and uniform microstructures and desirable mechanical performances, grain refiners were developed [2][3][4]6] and have been widely used for the purpose of casting light metals. At present, there are two strategies to reach fine and uniform microstructures in cast parts and alloys [3][4][5]. The conventional approach is to search for substrates of maximum potency to the metal, via segregation of impurities [3][4][5][6][7].…”

“…At present, there are two strategies to reach fine and uniform microstructures in cast parts and alloys [3][4][5]. The conventional approach is to search for substrates of maximum potency to the metal, via segregation of impurities [3][4][5][6][7]. A successful case is the application of the Al-nTi-B (n = 3, 5) grain refiners for casting Al-based metals [2][3][4][5][6][7].…”