Mg-Zn alloys

Stress-corrosion cracking occurs in certain aluminium alloys which have been developed for medium and high strength by employing variations in composition, cold work and heat treatment The main alloys are based upon Al-Mg, Al-Mg and Al-Cu, but stress corrosion also occurs in Al-Ag, Al-Cu-Mg, Al-Mg-Si, Al-Zn and Al-Cu-Mg-Zn alloys. It has... 

With very electropositive metais this oxide is reduced very violently following thermite type of reactions. Vioient reactions of this type happen with lithium, magnesium, aluminium and the Al-Mg-Zn alloy. The iron formed is melted due to the exothermicity of this reaction. This experiment is not recommended for lectures. 

Icosahedral Al-Mg-Zn type with a quasi-lattice constant of about 520 pm and a concentration of free electrons of about 2.1 electrons per atom. Examples are represented by Li3CuAl6 (ar = 504 pm, super-space-group Pm35), Li3AuA16, Pd13Mg44Al43, CuMg4Al6, Mg32Zn52Ga16, Y-Mg-Zn andY-Zr-Mg-Zn alloys, etc. 

Zn is an uncommonly good solvent for other metals (Ref 2) except for the refractory metals and W. By taking advantage of the high vapor pressure of Zn, it may later be removed by vacuum distln, leaving behind the solute in very fine dispersion in a highly reactive form. Likewise, the use of liq Mg—Zn alloy for the reduction of U oxides, Pu dioxide and Th dioxide to the metal has been investigated (Ref 3). The oxides were suspended in a flux composed of... 

The phase shift of the Friedel oscillations by k/2 from a cosine-function to a minus sine-function was recently reported as a common effect of the short mean-free path of the electrons [5.126], an interpretation quite similar to that argued by Kaneyoshi for the effective exchange interaction described in the review. Structure-induced pseudo gaps at EF in amorphous Mg-Zn alloys mentioned above, were confirmed and were also found in the mean time for Ca-Zn [5.127]. 

The preparation of UC from a liquid metal system has been studied by Johnson et al. (1963). A mixture of powdered uranium and charcoal in liquid Mg-Zn alloy at 800° gave UC as a precipitate after 2-5 hours. However, they found oxygen was a serious impurity in the final product. 

Figure 4-18. Tolerance limits for nickel in pure magnesium, and in Mg-Mn and Mg-Zn alloys (Makar and Kruger, 1993).

Calculate the activity coefficient and the activity of magnesium in a Mg-Zn alloy containing 0.32 atom fraction of magnesium at 727°C (1000 K). 

Chromium. It is usuaUy added to Al-Mg alloy and Al-Mg-Zn alloys in amounts of 0.1-0.3%. It has a beneficial influence on pitting resistance in seawater. 

Zn was reported to increase SCC susceptibility [60], although this was disputed by Fairman and Bray [106]. Mg-Zn alloys containing rare earths, such as ZExx, are considered to have moderate SCC susceptibility relative to Mg-Al-Zn alloys. AZxx alloys contain both Al and Zn and are considered particularly susceptible in air and chloride-containing solutions. They are also the most common, which is one reason why many studies have focused on Mg-Al alloys [114-120], Mg-Al-Zn alloys [104,106,121-125] and pure Mg [98, 99,101]. 

Shi, Z, Song, G Atrens, A (2003), Iiffects of zinc on the corrosion resistance of anodized coating on Mg-Zn alloys. In Dahle, A, ed. Proceedings of the 1st International Light Metals Technology Conference, Brisbane, Australia. CAST, 393-396. 

Li, J., Song, Y., Zhang, S., Zhao, C., Zhang, R, Zhang, X., Cao, L., Fan, Q., Tang, T., 2010. In vitro responses of human bone marrow stromal cells to a fluoridated hydroxyapatite coated biodegradable Mg-Zn alloy. Biomaterials 31, 5782-5788. 

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