Magnesium alloys applications

They are widely employed in the manufacture, storage and distribution of liquified gases, particularly on sea and road tankers. The most popular alloy for cryogenic applications is 4.5% magnesium alloy (N8). Table 3.33 gives the boiling points of the most common cryogenic liquids and the minimum temperatures at which various materials can be used. 

These are the second great field of application for aluminum alloys, with the exception of aluminum magnesium alloys. One restriction always applies... 

Unsworth Developments in Magnesium Alloys for Casting Applications , Metals and Materials, 83-86, February (1988)... 

It may be felt that the initiation of a stress-corrosion test involves no more than bringing the environment into contact with the specimen in which a stress is generated, but the order in which these steps are carried out may influence the results obtained, as may certain other actions at the start of the test. Thus, in outdoor exposure tests the time of the year at which the test is initiated can have a marked effect upon the time to failure as can the orientation of the specimen, i.e. according to whether the tension surface in bend specimens is horizontal upwards or downwards or at some other angle. But even in laboratory tests, the time at which the stress is applied in relation to the time at which the specimen is exposed to the environment may influence results. Figure 8.100 shows the effects of exposure for 3 h at the applied stress before the solution was introduced to the cell, upon the failure of a magnesium alloy immersed in a chromate-chloride solution. Clearly such prior creep extends the lifetime of specimens and raises the threshold stress very considerably and since other metals are known to be strain-rate sensitive in their cracking response, it is likely that the type of result apparent in Fig. 8.100 is more widely applicable. 

Both metals are applied to copper-base alloys, stainless steels and titanium to stop bimetallic corrosion at contacts between these metals and aluminium and magnesium alloys, and their application to non-stainless steel can serve this purpose as well as protecting the steel. In spite of their different potentials, zinc and cadmium appear to be equally effective for this purpose, even for contacts with magnesium alloys Choice between the two metals will therefore be made on the other grounds previously discussed. 

Aluminum-magnesium alloys, 2 311 chemical industry applications, 2 341 corrosion resistance, 2 336 finishes, 2 338... 

Cast magnesium alloys used for structural applications comprise a highly heterogeneous ductile matrix with several dominant types of inclusions that dictate fatigue resistance. We use the term inclusion as distinctly different from a crack, as the former occurs naturally as products of the casting process, while the latter is... 

Misch metal is an alloy of about 50% cerium, 25% lanthanum, 15% neodymium and 10% other rare earth metals. Uses include manufacture of a pyrophoric alloy with iron and deoxidizer in metallurgical applications, getter for removal of oxygen from vacuum tubes, high strength magnesium alloys. 

Application of SPD techniques to metal hydrides is a new field of research. Skripnyuk and Rabin were the first to use ECAP to improve the hydrogen storage properties of Mg-based alloys [254, 255]. The first study on ECAP-processed magnesium alloy ZK90 showed an improvement in sorption kinetics without loss of hydrogen capacity or change in thermodynamic parameters [254]. figure 4.12 shows comparable results for the Mg-Ni eutectic alloy [255]. 

SAFETY PROFILE A poison by ingestion, subcutaneous, parenteral, and intravenous routes. An irritant to skin and eyes. When heated to decomposition it emits vety toxic fumes of NO. An oxidizer. Mixtures with finely divided aluminum-magnesium alloys are easily ignitable and extremely sensitive to friction or impact. Such mixtures are used in chemical photoflash applications. Incompatible with (Mg + Ba02 + Zn), Al, and Mg alloys. When heated to decomposition it emits toxic fumes of NOx. See also BARIUM COMPOUNDS (soluble) and NITRATES. 

Strontium chromate is used in the following applications as a pigment, as an anticorrosive agent in aluminum and magnesium alloys, in vinyl sheeting, and in chemical-resistant coatings. 

Nowadays, the application of the ultrasonic treatment ensures the reliable reproduction of the nondendritic structure in ingots (Figure 25) from the majority of aluminum structural alloys of the Al-Cu-Mg-Mn and Al-Zn-Mg-Cu systems (ingots of 65 to 1200 mm in diameter) and from magnesium alloys (ingots to 270 mm in diameter) containing modifying additions of Zr. 

R. Udhayan and D.P. Bhatt, In International Conf on Magnesium alloys and their applications, Germisch-Partenkirchen, Germany (1992) 59. 

The primary benefit of magnesium in structural applications is its low density which is two-thirds that of aluminum. However, the use of magnesium alloys in the automotive sector continues to be restricted for more arduous applications where improved designs have increased component temperatures. Creep is considered a most important factor at working temperatures at or more than 423 K. 

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