SOME aluminium-compounds were used by man from the earliest of times. Primitive man-made pottery from clays containing hydrated aluminium silicate and aluminium salts used by the Egyptians in the preparation of dyes and medicines are just some examples.
Today aluminium and its alloys are used in the fabrication of various items ranging from pressurised vessels, automotive components right to domestic use of foil for cooking and baking purposes. As wonderful as this sounds aluminium is not the easiest metal to cut, grind or weld. aluminium clogs easily and has a very low melting point, therefore very sensitive to heat input and prone to cracking in the heat affected zone if impurities are present. For this reason, correct welding procedures must be followed.
Identifying and using the correct abrasive product, whether it be for cutting, grinding, or blending, is core to the successful completion of any job. Besides the safety risk involved when using incorrect products and the potential harm this may cause, the effect on production lead times and final finish of parts or items being manufactured should also be considered.
Metal contamination is a major cause of component and weld failure. and occur either through – direct contamination when using the incorrect abrasive products, cross contamination when using the same abrasives on multiple materials, or general contamination due to improper processing of materials in the work environment.
Direct contamination occurs when conventional cutting and grinding discs for steel are used for applications on Aluminium. Abrasive cutting and grinding discs, as well as coated abrasive flap discs, are designed and manufactured with various components that make up the final product. Some of these components like fibre reinforcing, are added to provide structure and support to the final product for strength and support to avoid breakage and damages when in use. Together with these components, other additives are also added into the mix to provide better results, usually by increasing the oxidative and corrosive effect in mild or carbon steels. However, such oxidative and corrosive compounds (iron, sulphur, and chlorine) can cause major issues down the production line when used on aluminium applications. If the work piece is not thoroughly cleaned of these compounds, should it become contaminated, subsequent welding processes will also be influenced and might cause welds not penetrating well, or porosity that will lead to weak welds that can cause catastrophic failures if not resolved
To avoid cross contamination, care should be taken to avoid using abrasive products on mild or carbon steel, and then on aluminium. Even though abrasive products are manufactured to be free of contaminants, unwanted iron, sulphur, and chlorine compounds will be introduced when used on mild or carbon steel, which will be transferred to the aluminium upon contact.
General workspace contamination can also contribute to contamination of various materials. Ideally, a floor layout should be planned in such a way that different material types are processed at opposite ends of a factory. This will ensure (to an extent) that swarf created during cutting, blending, or grinding operations will not come in contact with the aluminium metals in the vicinity, thereby eliminating the possibility of contaminating materials.
Grinding Techniques locally manufactures specialised abrasive products free of contaminants which are perfectly suited to applications on aluminium and stainless steels, like the Superflex Non-Ferrous range specifically manufactured for use on aluminium.
From cutting, grinding to blending and polishing a Superflex product suitable for an application is easily selected. The Superflex Non-Ferrous Cutting and Grinding range provide easy clean cuts and stock removal free from contamination and without the concern of discs clogging. Premium Non-Ferrous Ceramic flap discs will provide the ultimate surface finish whilst keeping heat input to a minimum to avoid discolouring.
Grinding Techniques provides a solution driven service through its national network of branches, with a technical sales force geared to provide the best possible product solutions to optimize production.
For more information, contact our Business Development Team for a tailor-made solution
+27 11 271 6400 | info@grindtech.com | www.grindtech.com
