Al-mg alloys for 3rs sem engg stud.pptx

Al-mg alloys

1. Aluminum alloys form the major airframe material and are used in abundance in the general structure of aircraft on account of their low specific gravity, reasonable strength case of fabrication and they are only 1/3rd as heavy as steel. Aluminium alloys are classified into two types: 1. Wrought alloys 2. Cast alloys Aluminium is found in most clays, soils, and rocks, but the principal commercial source is the ore bauxite. Bauxite is largely aluminium oxide mixed with impurities. These impurities are removed by a chemical process called Bayer's process, leaving the pure aluminum oxide, alumina.

2. An electrolytic process is used to obtain aluminum from the oxide. The metallic aluminum obtained by the electrolytic process is cast into pig form. These pigs are later remelted to form the commercial ingot used in rolling, forging, extruding, and other fabricating processes. By the addition of other constituents during the remelting operations, many alloys of aluminium are obtained with varying properties.

3. A.A . Number 1XXX Aluminum 99.00% (PURE) 2XXX Copper is the main alloying element 3XXX Manganese i s the m a in alloying e l ement 4XXX Silicon is the main alloying element 5XXX Magnesium i s the main alloying e l ement 6XXX Magnesium and silicon are the main alloyin g elements 7XXX Zinc is the main alloying element 8XXX Special element a lloys 9XXX Unused series Ex: Al6061: 6-alloy group; 0- impurity: 61- 99.61 (purity of Al used for composition) NOMENCLATURE: The Aluminum Association has published a new alloy designation system for aluminum alloys. The new system has all the wrought aluminum alloys designated by a four-digit system. The First digit indicates the principal alloying elements, the second digit is the modification(variation) of original material or impurity limits and the last two digits represents the aluminium alloy or aluminium purity.