High-strength non-combustible magnesium alloy

Abstract

The high-strength non-combustible magnesium alloy is obtained by adding at least one supplementary additive selected from among carbon (C), molybdenum (Mo), niobium (Nb), silicon (Si), tungsten (W), alumina (Al2O3), magnesium silicide (Mg2Si) and silicon carbide (SiC) to small chip-like blocks of a non-combustible magnesium alloy resulting from adding 0.5 to 5.0% by mass of calcium to a magnesium alloy to produce a crushed product, and subjecting the same to forming, sintering and plastic working. The high-strength non-combustible magnesium alloy exhibits excellent joining ability, and can therefore enhance weldability when used in a filler metal.

Description

TECHNICAL FIELD[0001]The present invention relates to a high-strength non-combustible magnesium alloy in which the mechanical strength of a non-combustible magnesium alloy is enhanced.BACKGROUND ART[0002]Magnesium alloys are very lightweight, for which reason they have received attention as substitutes for aluminum or aluminum alloys. Magnesium alloys belong to the lightest metals in practical use, and has, for instance, fairly high specific strength and specific elasticity modulus values, which result from dividing strength and elastic modulus by density. As a result, the demand for such magnesium alloys is expected to grow in the future in industrial fields where lightweightness is required. Although titanium and aluminum alloys are strong enough, they have the disadvantages of, for instance, being less lightweight and having poorer shock-absorbing characteristics than magnesium alloys.[0003]Although ordinary magnesium alloys exhibit comparatively high specific strength, their abs...

AI Technical Summary

Benefits of technology

[0024]An object of the present invention is to provide a non-combustible magnesium alloy imparted with high strength characteristics, including high tensile strength and high proof stress, through the addition of versatile elements and / or compounds, without using alloying elements limited to rare earth elements.

[0025]Another object of the present invention is to provide a non-combustible magnesium alloy, having improved stable weldability at low cost, that can be used as a filler metal.

[0044]As explained above, the high-strength non-combustible magnesium alloy of the present invention is a low-cost non-combustible magnesium alloy, to which high tensile strength and high proof stress is imparted by way of supplementary additives in the form of versatile elements and / or compounds, without using alloying elements limited to expensive rare earth elements, and by forming, sintering and plastic-working a crushed product. Thanks to having the ignition point thereof raised through addition of Ca, the non-combustible magnesium alloy of the present invention can be joined, as a filler metal, under ordinary conditions, giving rise to little fumes during welding (such fumes being substances that are vaporized by heat during welding or shearing and which cool into solid microparticles). Furthermore, the joining ability of the high-strength non-combustible magnesium alloy is enhanced, at low cost, by using effectively a crushed product of cutting chips or the like.

Problems solved by technology

Although titanium and aluminum alloys are strong enough, they have the disadvantages of, for instance, being less lightweight and having poorer shock-absorbing characteristics than magnesium alloys.

Such structural members inevitably require joining, in particular welding, between members.

However, magnesium alloys continue to be beset by numerous problems, being still unsatisfactory and insufficient for being used in actual articles.

In Patent document 2, expensive rare earth elements must be added, and thus the alloy obtained as a result is inevitably a high-cost alloy.

Except for the specified solute atom Ca, however, all other elements are rare earth elements, which makes hence for a high-cost alloy, as is the case above.

This indicates that a combination of high strength and high ductility cannot be achieved in the presence of either the intermetallic compound or the long-period phase alone.

However, Patent document 5 discloses no specific example of such a feature.

In all cases, expensive rare earth materials are added to the alloys.

This is problematic in that the magnesium alloys ultimately manufactured are likewise expensive.

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