JPH02232332A - Highly corrosive magnesium alloy - Google Patents

Abstract

PURPOSE:To obtain a Mg alloy which corrodes and disappears in sea water in a short time by adding specified amounts of one or more kinds among Ni, Fe and Cu to Mg. CONSTITUTION:As an Mg alloy material used on the sea or on the shore, and after the use, to be discarded in the sea and corrodes in a day or two to disappear, an Mg alloy having the compsn. of which either one or more kinds among Ni, Fe and Cu are added, in the total amt. of 0.02 to 5wt.%, to Mg is used. After the use, when discarded into the sea, the alloy corrodes rapidly in a short period of a day or two and disappears. For improving the extrudability, 0.5 to 3.5wt.% Al and 0.2 to 1.5wt.% Zn may be added to the Mg alloy.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnesium alloy that corrodes and disappears in seawater in a short period of time. [Background of the Invention] Structures that are used on the sea or on the coast (including in the air) and are dumped into the sea after use are at risk of getting caught in fishing nets and cutting them if they remain submerged in the sea. Therefore, it is preferable to use a material that corrodes and disappears within a short period of time after being dumped into the sea.

Up to now, there has been no suitable material that meets these requirements.

[Means for solving problems and their effects]

In view of the above circumstances, the inventors of the present invention have conducted intensive research to obtain an alloy that corrodes and disappears in seawater in a short period of time. We found that the base alloy corrodes quickly in seawater, and that the time required for corrosion and disappearance can be freely changed by changing the amounts of Ni, Fe, and Cu added. For example, in the case of a member with a thickness of about 2 days, if Ni is added alone, it will be 0.
．． 1 in seawater when added in excess of 5% (weight%, same hereinafter).
It disappears completely within days. Furthermore, if Fe alone is added in an amount of 1% or more, Cu alone is added in an amount of 2% or more, and it completely disappears within two days in seawater. Although Mg is originally a highly corrosive metal, the corrosion rate in seawater by itself is not very high. In order to increase the corrosion rate of Mg in seawater, it is necessary to contain 0.02% or more of the above elements (total amount if two or more types are included); if less than that, the corrosion rate will be that of pure Mg. There is almost no difference. Also N +
If the content of s Fe and Cu exceeds 5% (&81L if two or more are included), it becomes difficult to melt the added elements during casting, and workability deteriorates. Therefore, the highly corrosive magnesium alloy of the present invention has Ni
．． ．． It is characterized by containing one or more of Fe and Cu in a total amount of 0.02 to 5%, with the balance being Mg and inevitable impurities. Furthermore, in order to improve the extrusion processability of this alloy, Af and Z
It is effective to add n. In order to improve extrusion processability, it is effective to add 0.5% or more of AI and 0.2% or more of Zn, but if the amount added is too large, the corrosion rate will decrease significantly, so the AI should be 3.5% or less. , Zn is 1, 5
It is preferable to suppress it within %. [Example] Examples of the present invention will be explained below. This shows the results of investigating the time taken for corrosion and disappearance by immersing it in seawater. Samples 1kl to 10 are alloys of the present invention, and samples 11 to 14 are alloys for comparison. As shown in Table 1, cracks occurred and a good extrusion molded product could not be obtained. [Effects of the Invention] As explained above, according to the present invention, it is possible to obtain a magnesium alloy that corrodes and disappears within a short time after being dumped into the sea. This has the advantage of being able to construct a structure that does not pose any risk of accidents such as cutting fishing nets. Patent applicant: Ryozo Enkui, Defense Agency Technology Research Headquarters

Claims (2)

[Claims] (1) Highly corrosive, characterized by containing one or more of Ni, Fe, and Cu in a total amount of 0.02 to 5% (by weight, the same hereinafter), with the remainder consisting of Mg and inevitable impurities. magnesium alloy. (2) Any one or more of Ni, Fe and Cu in a total amount of 0.02 to 5% (weight%, same hereinafter), A
Contains 0.5 to 3.5% of l, 0.2 to 1.5% of Zn,
A highly corrosive magnesium alloy for extruded materials, characterized in that the remainder consists of Mg and inevitable impurities.