Aluminium Alloys
to cause substantial lowering of the melting point without producing brittleness in the formation of alloys. These alloys are non heat treatable but due to alloying elements it responds well to the heat treatment to an extent. Hence aluminium-silicon alloys are used in welding wire and as brazing alloys where lower melting point is required. 5000 SERIES Magnesium is one of the most effective and widely used alloying elements for aluminium. Magnesium is considerably much effective than manganese as it is stronger and harder, about 0.8% magnesium being equal to 1.25% manganese, and it can be added in considerably higher quantities. These alloys are also known as marine grade alloys (5083,5086) as they are widely used in marine applications. When it is used as the major alloying element, or with manganese, the result is a moderate to high- strength non-heat treatable alloy Alloys in this series possess good welding characteristics and good resistance to corrosion in marine atmospheres.
Metalmentalist - June 2012
6000 SERIES These alloys are not as strong as the 2000 series alloys or 5000 series alloys as they are alloyed with magnesium and silicon which are easy in machining. Alloys in this group contain silicon and magnesium in approximate proportions thus making them capable of being heat-treated. As compared to other strong alloys, with average strength these alloys possess good formability and corrosion resistance. 7000 SERIES The strongest of all the alloys in Aluminium, They are known as aerospace alloys. This alloy is the most important alloy in current aerospace industry. Zinc being the major alloying element in this group, and added with a smaller percentage of the magnesium results in heat-treatable alloys of very high strength. Usually other elements such as coppers and chromium are also added in small quantities. They are alloyed with zinc, and can be precipitation hardened to the highest strengths of any aluminum alloy. 27