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Novel Hypereutectic Si-Al alloys Are Not Foundry Alloys
As a versatile material,the hypereutectic Si-Al alloys have been commonly used in automobiles,motorcycles and tactical vehicles.Applications of the Al-Si alloys in the automotive industry,including engine blocks and parts of engines,particularly,cylinder liners.The following reason is why we introduce the aluminum alloys cylinder liner for the engine blocks. As we all known,fuel consumption is a serious problem exsiting in the operation of automobiles.More fuel consumption also means greater pollution emissions.The reduction in cylinder distortion (higher dimensional stability) that is possible with this alloy results in less noise and friction; engine-oil consumption and exhaust emissions are thus reduced, e.g 1kg hypereutectic Al-Si alloy can replacement 3kg casting alloy,the overall performance of automobiles can be enhanced.The hypereutectic Al-Si alloys material shows good wear-resistance combined with low coefficient of thermal expansion and have a high strength-weight-ratio.Hereby,it can remarkably improved the workability and ductility for the highest operation demands.Finally, the blanks are specially treated in an environmentally friendly process, aqueous exposure. The resulting smooth surface structure improves friction characteristics and cuts the engine's oil consumption and hydrocarbon-emissions levels.Thereby，curretly the use of cyliner liners made of hypereutectic aluminum alloys have been preferred and applied by many automobile manufacturers.At the same time,the Al-Si alloys are what is known as DISPAL ALUMINUM ALLOYS by most automakers around the world.
However,the hypereutectic Al-Si alloys materials are fabricated by our proprietary technology of Rapid Solidification at T6 condition(Solution heat treatment process).Herein,the silicon content by the weight of 20%~35% in the alloy which features excellent wear-resistance,high temperature strength,heat stability as well as high abrasion resistance.The AlSi25 alloys are relatively easy to honing and grinding,both for bars billets and cylinder sleeves tubes.They are machinable to a very fine finish(0.5μm~5μm) with carbide or poly-crystalline diamond(PCD) tools.
Tensile Strength MPa
Yield Strength MPa
Performance parameters of hypereutectic Al-Si alloy for autoparts
But,the aluminium foundry alloys are used for aluminium castings.Alloys are produced as continuous cast or mold casting ingots.The products are stacked and strapped into bundles of various size.And most used alloy groups,including AlSi7Mg alloys,AlSi9Mg alloys,AlSi11(Mg) alloys,AlSi10MgMn alloys and AlSi5-9MgCu alloys and etc.Its application area covers automotive and transport,eg.wheels,chassis components as brake parts and suspection parts,cylinder heads with key benefits of excellent castability,high and consistent metal quality and low level of impurities and trace.