Aluminium is the third most abundant chemical
In the modern era the term aluminium is more likely to refer to a vast range of aluminium alloys where its presence brings a combination of light weight and corrosion resistance. The terms Aircraft Aluminium or Aerospace Aluminium generally refer to alloy 7075, an aluminium alloy that incorporates zinc, magnesium and copper along with minor amounts of iron, silicon, manganese, titanium, chromium and other metals. This alloy exhibits exceptionally high strength but there are several other aluminium alloys that are commonly used in aircraft and aerospace structures. The Chemical Etching Process Chemical etching is a subtractive, tightly controlled corrosion process that can produce highly complex metal parts with very fine detail accurately and economically. For thin gauge precision parts, chemical etching can offer a more cost effective alternative to stamping, punching, laser or waterjet cutting. Many chemical etching companies claim to be able to etch aluminium. If it is not that difficult, then why do we not see many more etched aluminium components? The answer lies in the problematical nature of the process in terms of speed, a major factor that affects its the commercial success. Aluminium and its alloys have always proved difficult to machine in a conventional way, in view of their ductility and predisposition to 'pick-up' on the tool face. Similarly with etching... the process is not simple. With so may alloy formulae available it is invariably necessary to modify the etchant chemistry in order to optimise the etching process for each alloy combination. In order to achieve success, the chemical etcher must have a thorough understanding of the process requirements, the knowledge resource develop multiple solutions and an innovative approach to etchant chemistry. One innovative application for etched aerospace alloys is in printed circuit, liquid-to-liquid heat exchangers, which use aluminium in preference to other metals because of its light weight. Liquid cooling provides significantly better performance than air cooling alone; can be insensitive to altitude and allows engineers to optimise critical system performance. However, Aircraft Aluminium is not the exclusive property of the aerospace industry. 7000 series alloys such as 7075 are often used in marine and automotive applications due to their high strength-to-density ratio. This combination is also favoured in other fields such as the military.