Sodden timber lying flat on aluminium, or moist insulation in contact with it are examples of absorbent material acting with a poultice effect. Attack of aluminium by very weak corrosive solutions, such as contaminated rain water, is often insignificant if not prolonged, but it becomes important if circumstances cause the solution to be retained in contact with the metal. In the presence of specific substances simple chemical attack may occur. Several characteristic modes of attack on aluminium may be distinguished. In every climate where the atmosphere is at all humid, building and engineering materials undergo some chemical change with the passage of time and are subject to some form of corrosion. The comments which follow apply mostly to unanodised aluminium. For many purposes, decorative as well as protective, the naturally-formed oxide film is thickened by anodising and the protective value of the oxide film is thus considerably increased. The immunity of aluminium to the atmosphere arises from the protective nature of the oxide film which acts as a barrier to corrosion. Most of the standard aluminium alloys supplied for architectural and structural applications (e.g. McKechnie Aluminium 6060, 6063, 61a, 6061 etc.) perform very satisfactorily in normal exposed positions. Aluminium is no exception and needs to be installed in proper fashion if best use is to be made of it and maximum service is to be obtained. Toitū carbonreduce 3rd Party Certification - Sustainably Leading The IndustryĪll materials of construction have individual characteristics which call for special consideration in design, fabrication and installation.Toitū 3rd Party Certification - Sustainably Leading The Industry.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |