Magnesium matrix

In commercial alloys, 2inc is usually dissolved in the magnesium matrix and in the hard magnesium—aluminum phase when aluminum is present. Zinc additions to magnesium—aluminum alloys change the eutectic stmcture to a so-called divorced eutectic, characteri2ed by the presence of massive compound particles surrounded by a magnesium-rich sohd solution. 

Effect of size and surface treatment of carbon fibers on mechanical properties of magnesium matrix composites ... 

D.J. Lloyd Particle reinforced aluminium and magnesium matrix composites. Int. Mater. Rev. 39, 1-23 (1994)... 

Key words magnesium matrix composites, magnesium alloys, creep, short-fibre reinforcement, particle reinforcement... 

Thus, the aim of the present paper is not to review the bulk of the results published to date relating to the creep response of various magnesium-based composites. Instead of such an approach this paper provides a comprehensive report on the extensive experimental results obtained by authors in an investigation of the high temperature creep behavior of the two magnesium alloys, AZ 91 and QE 22, and their discontinuous composites. The objective of the present research is a further attempt to clarify the direct and indirect strengthening effects of short-fiber and particulate reinforcements in creep of magnesium-matrix composites. 

Chen Y, Zhang GD, Wu F, Zhu J, Study of the C/Mg interface in magnesium matrix composites reinforced by carbon (graphite) fiber, Rare Metal Mater Eng, 26(3), 20-25, 1997. 

Divecha AP, Karmarkar SD, Foltz JV, Process for producing graphite fiber j aluminium-magnesium matrix composites, U.S. Pat., 4578287, Mar 1986. 

The early magnesium alloys suffered rapid attack under moist conditions, mainly because of the presence of impurities, notably iron, nickel, and copper. These impurities or their compounds act as minute cathodes in the presence of a corroding medium and create micro-cells with the anodic magnesium matrix (Polmear, 1989). High-purity alloys are a relatively recent development. In high-purity alloys the concentrations of these impurities are controlled to below critical concentrations and as a consequence high-purity alloys are markedly more resistant to salt water than are alloys of normal purity (Shreir, 1965). 

Such components either have appreeiable solid solntion solubility with the magnesium matrix (aluminum for example) or they are only sparingly soluble sueh as manganese and the rare earth metals (Nordlien et ah, 1996). On the other hand, rednetion of the heavy metal content and applieation of appropriate heat treatments have already, led at least partially, to inereased corrosion resistance of eertain Mg alloys. Amorphons oxides are in general considered to have mneh better passive properties than erystalline ones and stability of the inner layer on magnesinm is responsible for the passivity of the surface in aqneons environments. 

Hong, Y., Xiaowu, H., Qiao, N., Lei, C., 2011. Aging behaviour of nano-SiC particle reinforced AZ61 magnesium matrix composites. China Foundry 8 (3). 

Zhao-hui, W., Xu-dong, W., Zhaou-xin, W., Wen-bo, D., 2010. SiC nanoparticles reinforced magnesium matrix composites fabricated by ultrasonic method. Transactions of Nonferrous Metals Society of China 20, 1029—1032. 

Aside from the Group I and If elements and Co, Co, Ni, Ni, Ag, " " Ag, B, Mn and S, all other elements indicated full abatement (95 5 %) as would be expected in the absence of the magnesium matrix. For example, the slight abatement of boron is consistent with the chemistry of boric acid. Boric acid B(OH)3 or H3BO3 is a weak mono-basic Lewis... 

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