Soft magnetic alloy for microwire casting

Abstract

An alloy, which can be used in a microwire, contains 26 to 52 weight % Fe; 26 to 52 weight % Co; 3.0 to 38.0 weight % Ni; at least one selected from the group consisting of 1.0 to 8.0 weight % V, 1.0 to 8.0 weight % Cr, 1.0 to 8.0 weight % Zr, 1.0 to 8.0 weight % Dy and 1.0 to 8.0 weight % Nb; at least one selected from the group consisting of 2.0 to 8.3 weight % Si and 2.0 to 8.3 weight % B; and at least one selected from the group consisting of 0.2 to 1.6 weight % Ce, 0.2 to 1.6 weight % La and 0.2 to 1.6 weight % Y. When cast in a microwire, the alloy can be substantially amorphous.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] This invention relates to high precision alloys. In particular, the present invention relates to amorphous, soft magnetic compositions having various coercive forces and to the use of the compositions in the fabrication of glass-coated microwires by the method of rapid quenching from a liquid phase. [0003] 2. Description of the Background [0004] It has been the tendency in modern technologies to demand new materials and processes for their production from material engineering. One of the problems encountered in material engineering is the production of materials having predetermined properties. [0005] It has also been the tendency in modern technologies to demand miniaturization techniques that use new materials. There are various technical solutions in miniaturization technologies that require magnetic microwires. For example, use of amorphous glass-coated microwire allows the sensitivity and precision of various r...

AI Technical Summary

Benefits of technology

"The present invention provides a novel amorphous alloy that can be used to produce microwires with excellent magnetic characteristics and a wide range of coercive force. The alloy contains Fe, Co, Ni, and at least one element from the group consisting of V, Cr, Zr, Nb, Dy, Si, B, and rare-earth elements such as Ce, La, Y. The alloy can also contain additional elements such as Si and B. The content of certain elements in the alloy can provide a wide coercivity range. The alloy has good mechanical properties and can be produced as long continuous microwires. The rare-earth elements provide reliable purification of the alloy. The alloy can be produced using a casting production process."

Problems solved by technology

One of the problems encountered in material engineering is the production of materials having predetermined properties.

These alloys cannot be used in glass coated microwires because of various physical and chemical interactions between the molten alloy and glass during the microwire casting process.

In particular, the wetting ability of these alloys by glass is not sufficient.

The alloys shown in Table 2 and disclosed in the '599 and '605 patents are not suitable for a mass microwire manufacturing process because the wetting ability of glasses by the molten alloys is not sufficient and there is insufficient purification of the alloys from entrapped gases and other non-metallic inclusions.

A disadvantage of the obtained material is the fact that the possible variations of this parameter are slight and independent of alloy composition.

Another disadvantage of this alloy is the fact that content of such modifiers as V, Cr, Zr and Nb is about 15-30%.

That leads to destruction of the magnetic phase in the soft magnetic alloy and a sharp decrease the magnetic permeability and other magnetic properties.

These conditions render impossible a stable microwire casting process.

Formation of the unstable isolated phases leads to embrittlement of the alloy and the brittleness of the microwire is increased.

Such a concentration of amorphizator leads to sharp increase of interfacial tension and a stable microwire process is impossible.

Moreover in this case the microwire is extremely brittle.

A disadvantage with these amorphous alloys is that wires of the alloys have an insufficient tensile strength because of insufficient purification of the alloys from entrapped gas and other non-metallic inclusions.

However, the alloys do not satisfy the following requirements: 1. controlled soft magnetic composition of the alloy; 2. fabrication of microwire having long continuous length (because of insufficient purification of the alloy from the entrapped gas and other non-metallic inclusions); 3. stable casting process (because of insufficient wetting ability of glasses by metal melt); 4. variation of coercivity (0.5-1200 A / m); and 5. high temperature stability (not less than 600° C.) for realization of a final thermo treatment at the higher temperature and low isothermal storage.

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