Heat-resistant magnesium alloy

Abstract

A heat-resistant magnesium alloy according to the present invention has Mg as the major component, includes Al, Ca and Mg, and has a metallic structure that comprises Mg crystalline grains and grain-boundary crystallized substances being crystallized out in a grain boundary between the Mg crystalline particles. The grain-boundary crystallized substances comprise a mixed crystal phase of a Laves-phase compound with a type-“C14” crystalline structure, and another Laves-phase compound with a type-“C36” crystalline structure. Moreover, a relative angle between a normal vector to the hexagonal-system basal plane of the Mg crystalline grains and another normal vector to the hexagonal-system basal plane of the grain-boundary crystallized substances is from 88 deg. to 92 deg. at an interface between the Mg crystalline grains and the grain-boundary crystallized substances at least. The present magnesium alloy exhibits high mechanical characteristics in high-temperature atmospheres, because it has the metallic structure in which a basal-plane slip is much less likely to occur than ever before, and because the basal-plane slip is less likely to occur even at high temperatures.

Description

TECHNICAL FIELD[0001]The present invention is one which relates to a heat-resistant magnesium alloy that is capable of withstanding services under high loads and at high temperatures.BACKGROUND ART[0002]Magnesium alloy, which is more lightweight than aluminum alloy is, is about to be used widely for air-craft material, vehicle material, and the like, from the viewpoint of weight saving. However, magnesium alloy has been required to be furthermore upgraded in the characteristics, because it is not satisfactory in the heat resistance, as well as in the strength, depending on applications or purposes.[0003]Hence, in Patent Literature No. 1 (Japanese Unexamined Patent Publication (KOKAI) Gazette No. 2004-162,090), and in Patent Literature No. 2 (Japanese Unexamined Patent Publication (KOKAI) Gazette No. 2004-232,060), there are disclosed magnesium alloys in which calcium (Ca) and aluminum (Al) are contained in adequate amounts, respectively. According to these literatures, the movements...

AI Technical Summary

Benefits of technology

The present invention relates to a heat-resistant magnesium alloy that has good heat resistance. The metallic structure of the alloy is controlled by adding appropriate alloying elements and adjusting their amounts. The alloy has a metallic structure that includes Mg crystalline grains and grain-boundary crystallized substances. The grain-boundary crystallized substances are made of a mixed crystal phase of a Laves-phase compound with a type-“C14” crystalline structure and another Laves-phase compound with a type-“C36” crystalline structure. The relative angle between the normal vectors to the hexagonal-system basal planes of the Mg crystalline grains and the grain-boundary crystallized substances is from 88 deg. to 92 deg. The heat-resistant magnesium alloy has high strength and is stable even at high temperatures.

Problems solved by technology

However, magnesium alloy has been required to be furthermore upgraded in the characteristics, because it is not satisfactory in the heat resistance, as well as in the strength, depending on applications or purposes.

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