High strength aluminum alloy casting and method of production of same

Abstract

A high strength aluminum alloy casting obtained by casting an aluminum alloy comprised of 7.5 to 11.5 wt % of Si, 3.8 to 4.8 wt % of Cu, 0.45 to 0.65 wt % of Mg, 0.4 to 0.7 wt % of Fe, 0.35 to 0.45 wt % of Mn, and the balance of Al and not more than 0.2 wt % of unavoidable impurities, wherein this aluminum alloy has 0.1 to 0.3 wt % of Ag added to it or contains 0.1 to 1.0 wt % of at least one element selected from the group of second additive elements comprised of Rb, K, Ba, Sr, Zr, Nb, Ta, V, and Pd and rare earth elements, and a method of production of a high strength aluminum alloy casting comprising the steps of filling a melt of an aluminum alloy in a mold to obtain a casting, taking out the aluminum alloy casting from the mold, solubilizing the high strength aluminum alloy casting by heating in a temperature range of 495 to 505° C. for 2 to 6 hours, quenching the high strength aluminum alloy casting after the solubilization, and age hardening the high strength aluminum alloy casting by heating in a temperature range of 160 to 220° C. for 2 to 6 hours after quenching.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a high strength aluminum alloy casting having superior mechanical properties, a high strength aluminum alloy casting including a neutralizing casting defect element for increasing the strength (hereinafter also referred to as an “NCDE”), and parts made from this high strength aluminum alloy casting such as a scroll for a compressor for an air-conditioner, a vane rotor of a valve timing regulating device, and a housing of an antilock braking system. Further, the present invention relates to a method of production of the above high strength aluminum alloy casting, a method of production of a high strength aluminum alloy casting including a neutralizing casting defect element, and a method of production of parts made from this high strength aluminum alloy casting such as a scroll for a compressor of an air-conditioner, a vane rotor of a valve timing regulating device, and a housing of a...

AI Technical Summary

Benefits of technology

The present invention provides a high strength aluminum alloy casting that has improved strength, fatigue resistance, and durability. The alloy contains specific amounts of silicon, copper, magnesium, iron, and rare earth elements, which work together to enhance the strength of the alloy. The alloy can be cast using a die cast method, and the resulting casting has a uniform structure and reduced defects. The invention also provides a scroll for a compressor of an air-conditioner made from the high strength aluminum alloy casting, and a method of production of the scroll. The technical effects of the invention include improved strength, reduced casting costs, improved productivity, and reduced defects in the final product.

Problems solved by technology

Further, in the method of production, it was confirmed that the tensile strength, yield strength, and fatigue strength of the die castings were enhanced, but these aluminum alloy die castings have casting structures formed as meshes, so were inferior in properties compared with aluminum alloy die castings solubilized and age hardened to make the eutectic Si spherical (T6 treatment).

With just the improvements of the method of production described in Japanese Unexamined Patent Publication (Kokai) No. 2000-192180, it is not possible to satisfy the design requirements of aluminum alloy scrolls.

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