Grain refinement efficiency and mechanism of aluminium carbide in Mg–Al alloys

Effects of Carbon and/or Alkaline Earth Elements on Grain Refinement and Tensile Strength of AZ31 Alloy

“…1. For the grain refinement of Mg-Al alloys by carbon, the hypothesis that the Al 4 C 3 particles should play an important role in grain refinement has been widely accepted by many researchers, [11][12][13][14][15][16][17][18][19] although Al-C-O particles were usually found in Mg-Al alloys modified by carbon. 11,12,16) From the viewpoint of lattice disregistry, both Al 4 C 3 and Al 2 CO are suitable for acting as nucleating particles for the magnesium phase with the planar disregistries of only 4% and 0.9%, respectively. Their crystal structures and lattice parameters are listed in Table 1. 13) Recently, the theoretical results calculated by Zhang et al 30) showed that the Al-C-O particles with the form of Al 2 CO are effective nucleating particles for -Mg grains.…”

“…6,7) The main grain refining methods for this group alloys are superheating, 8,9) FeCl 3 inoculation, 10) carbon inoculation [11][12][13][14][15][16][17][18][19] and addition of solute elements. 4,[20][21][22][23][24][25] Among them, the carbon inoculation has the advantages in the low cost, the low operating temperature and the less fading.…”

“…This hypothesis has been widely appreciated by other researchers. [11][12][13][14][15][16] As for the Mg-Al alloys, the addition of solute elements (e.g. Ca, Sr, RE) is another important grain refining method.…”

An Analysis of the Grain Refinement of Magnesium By Zirconium

“…In the recent past extensive research has been focused on developing new grain refiner for magnesium cast alloys, and a number of grain refiners have been reported, such as zirconium for magnesium alloys which do not contain elements such as aluminum, manganese and silicon, since zirconium forms stable compounds with these elements [5] and Al 4 C 3 [47,48], SiC [49,50] or by carbon inoculation [51,52] for aluminum bearing magnesium alloy. Although the dependence of grain refining efficiency at different addition level of inoculated particles has been investigated [53,54] there is still lack of experimental data on the role of the active particles in grain refinement.…”

Refino de grão das ligas do sistema cobre-estanho.

“…Os precipitados facetados existentes na amostra do experimento Cu8Sn0,08Zr indicam um bom substrato para a nucleação heterogênea, mas há evidências de que o efeito é muito mais significante quando o desajuste é menor do que 5% (TURNBULL; VONNEGUT, 1952;BRAMFITT, 1970;MONDOLFO, 1982;CAI et al, 2000;LU et al, 2005;WANG et al, 2006). …”