Properties of clad sheets

The effect of full heat treatment includes the effect of hardening and aging effect. Different aluminum alloys the influence of quenching and aging on the strength of different.

Aging

This process, when the alloy after quenching without polymorphic transformation is the decomposition of the supersaturated solid solution. The phenomenon of aging of aluminum alloys was opened by the Wilm. He found that an alloy of aluminum with copper and magnesium, tempered at 500 °C in water, after four days of standing at room temperature became stronger and stronger, without losing ductility. When heated, the aging process accelerates. From duralumin alloys, the greatest effect of the heat treatment of the alloy D16. Aging, running at normal temperatures, adopted the term «natural aging» and aging in the special conditions of heating after quenching — «artificial aging». Structural transformations during aging need to be explained. The decomposition of the solid solution is usually in three stages. 1) Education coherent with the matrix, GP zones (by Guinier-Preston), 2) formation of partially coherent metastable phases, 3) the formation of incoherent particles of the stable phase. Some alloys will not age at room temperature and to ageing, require a special heater. Other alloys of the transition from natural to artificial aging (i.e., from zones to the phases) occurs at room temperature, however, at very long exposures.

Aging of aluminum

Naturally aged alloys of aluminum while maintaining ductility have less strength compared with the annealed alloys. The fact that at 20−100°C hardening occurs due to the formation of GP zones, while at higher temperatures there is a selection of metastable phase S' (stable S-Al₂ CuMg). Further increase in temperature and the aging time leads to coagulation of metastable phases and loss of strength. In industrial production for the delivery and assessment of the quality of the alloy D16 is accelerated aging at 100 °C for several hours (not waiting the four days of the completion of the natural aging at room temperature). This is justified as in both cases a comparable process of aging and conditioning is achieved the same strength. This limits separation of the particles of metastable phases that reduce the corrosion resistance.

Note:
σв: temporary resistance, MPa (kgf/mm2)
σ0,2: yield strength, MPa (kgf/mm2)
β: the relative elongation in %

To buy, price

In stock, LLC «Electrocentury-steel» in a wide range of aluminum rolled products. Supply of products from aluminium alloys after heat treatment. All products are certified. We value our customers and are always ready to help you with your optimal choice. It offers experienced managers-consultants. Product quality is guaranteed by strict observance of the norms of production. The timing of orders is minimal. Wholesale buyers get a preferential discount.

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