Classification of magnesium alloys

Refers to its main alloy elements: Mg-Al, Mg-Mn, Mg-Zn, Mg-Si, Mg-RE, Mg-Zr, Mg-Th, Mg-Ag and Mg-Li, etc. Binary alloy; Mg-Al-Zn, Mg-Al-Mn, Mg-Mn-Ce, Mg-RE-Zr, Mg-Zn-Zr and other triple alloys; Mg-Zn-RE-Zr, 4-element alloys such as Mg-Al-Mn-Zn, Mg-Zn-RE-Zr, Mg-Zn-Zr-Ag, Mg-Al-Mn-Zn; and more complex polyhedra Gold, such as Mg-Ag-Th-RE-Zr, etc.

Conventional magnesium alloy varieties are far less than aluminum alloys, not as rich as copper alloys, but new alloy systems are constantly emerging The excellent performance of magnesium alloys stands out, and some of them especially new alloy elements become hot spots.

Adding trace amounts of surfactants such as calcium, strontium, barium, antimony, tin, lead, and palladium to existing magnesium alloys Gold elements, redesign the alloy composition to obtain good composite performance or new magnesium with special properties alloys. A new type of space-based palladium-magnesium alloy has been used in practical applications, such as for the manufacture of rocket and spacecraft components The Mg-Th-Zr, Mg-Th-Zn-Zr and Mg-Ag-Th-RE-Zr alloys have achieved good results. Results. However, Th is a radioactive element that is harmful to human health and the environment. Restricted use. Some countries, such as the UK regulations and regulations for alloys with Th content greater than 2% as radioactive materials. This is not only cumbersome, but also Increases the difficulty and cost of manufacturing parts. Rare earth elements can give magnesium alloys a range of excellent Performance, promising to be the ideal magnesium alloy element to replace palladium. It seems that Mg-RE alloy prospects are bright.

According to the molding process

Magnesium alloy can be divided into: casting and deformation, the former accounts for more than 85% of magnesium consumption, due to magnesium alloy processing into Poor type performance, complex production process, high processing costs, greatly limiting its scope of application. These two types of alloys are very different in composition and metallurgical tissue performance, casting magnesium alloy is mainly used for die casting Spare parts such as transportation equipment, machinery, electronic and electrical products. Die casting magnesium alloy has high casting efficiency, table Excellent surface quality, good casting organization, fine grain uniformity and other advantages, can manufacture complex shapes, arbitrary walls Thick workpieces.

Aluminum has a good strengthening effect, magnesium alloy casting performance is good, but the aluminum content should not be less than 3%; zinc also It is a strengthening element of magnesium alloy, but when its content exceeds 2%, there is a strong tendency to thermal cracking; Mn can be combined with Al, Fe binds to form AlFeMn compounds that are denser than magnesium alloy melts, so AlFeMn compounds will sink into the furnace bottom and mixed with sludge to remove harmful impurities Fe. Mn can also refine tissue; rare earth elements can be used for Introducing some other properties for magnesium alloy casting performance. Ni, Fe, Cu reduce magnesium alloy corrosion resistance, is Extremely harmful impurities should be strictly controlled.

In order to promote the application of magnesium alloy in the structure, the study of deformed magnesium alloy should be strengthened. Since magnesium is dense The hexagonal lattice, whose plastic deformation capacity is much lower than that of aluminum and aluminum alloys, is almost impossible to obtain both high Magnesium alloy with room temperature strength and good machining performance. Therefore, the early deformation of magnesium alloy does not contain gold Intergenus compounds or as little as possible according to their tissue requirements when designed, so that the magnesium alloy maintains good plasticity and Mechanical properties, the improvement of alloy strength performance is mainly strengthened by solid solution. Alloy elements and plastic deformation caused by Process hardening.

Currently deformed magnesium alloy used main alloy elements are aluminum, manganese, rare earths, yttrium, zirconium and zinc, on the one hand It can improve the strength performance of magnesium alloy, improve the thermal deformation ability of magnesium. The alloy is conducive to forging and pressing  . AZ31B, C, E alloys are high strength, good plasticity, widely used in extrusion production. They are Mg-Al-Mn-Zn alloys Gold, the alloy elements are the same, but the impurity content is different. For the AZ31 series alloy in rolling plate strip, As the aluminum content increases, the tendency to crack increases, so AZ61 alloy is almost never used for rolling plate strips Oh.

Whether it contains zirconium or aluminum:

Aluminum and zirconium are the most important alloy elements of magnesium alloy, so depending on whether it contains aluminum and zirconium, it can be divided into aluminum Or magnesium alloys containing zirconium and magnesium alloys without aluminum or zirconium.

Zirconium is a valuable alloy element of magnesium alloy, which has a strong grain refining effect, but with Mn, A l Combined to form a stable density intermetallic compound, sink into the crucible or furnace bottom, weaken or even eliminate harmful  . It should play the role. So in addition to MBI5 alloy, other deformed magnesium alloy does not contain zirconium, cast Magnesium alloys ZM5 and ZM10 are the same.