Nd-based two-phase separation amorphous alloy

Abstract

Provided is a Nd-based two-phase separation amorphous alloy by adding an element having a big difference in heat of mixing in a Nd-based alloy with a superior amorphous formability through an inherent characteristic of compositional elements and consideration of thermodynamics, at the time of forming amorphous phase, to thereby enable two-phase separation amorphous alloy during solidification. The Nd-based two-phase separation amorphous alloy which is represented as a general equation Nd100-a-b(TM)a(D)b wherein TM is a transition metal which is a combination of respective one selected from A-B, A-C and B-C when a group of A consists of Y, Ti, Zr, La, Pr, Gd, and Hf, a group of B consists of Fe, and Mn, and a group of C consists of Co, Ni, Cu, and Ag, wherein the content of the element group which constitutes each combination is 5 atomic weight % or greater, and the element selected from each element group is at least one, and wherein D is at least one selected from the group consisting of Al, B, Si and P, and a and b have the range of 20≦a≦80, and 5≦b≦30, respectively, in terms of atomic weight %.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a neodymium-based (Nd-based) two-phase separation amorphous alloy, and more particularly, to a Nd-based two-phase separation amorphous alloy by adding an element having a big difference in heat of mixing in a Nd-based alloy with excellent glass forming ability through an inherent characteristic of compositional elements and consideration of thermodynamics, at the time of forming amorphous phase, to thereby obtain a two-phase separation amorphous alloy during solidification.[0003]2. Description of the Related Art[0004]Amorphous metal can be defined as the atomic positions of the liquid phase are conceptually stopped in view of the structural analysis. Researches on the structural analysis of initial amorphous metal materials have been performed through Roentgen rays or electron diffraction based on a controversy whether the structure of the initial amorphous metal materials are amorphous ...

AI Technical Summary

Benefits of technology

[0016]To solve the above problems, it is an object of the present invention to provide a Nd-based two-phase separation amorphous alloy in which elements having a big difference of heat of mixing are added in a Nd-based bulk amorphous alloy composition which has been reported to have an excellent glass forming ability through an inherent characteristic of compositional elements and consideration of thermodynamics, to thereby enable two-phase separation amorphous alloy during solidification, and the two-phase separated amorphous phase shows up a conspicuously separated crystallization behavior according to an inherent crystallization temperature difference of main elements, respectively, with a result that 1) manufacturing of the composite material is facilitated through nano-crystallization, 2) a multi-stage forming can be performed in a supercooled liquid region corresponding to the amorphous phase, respectively, and 3) a magnetic property can be improved by the amorphous phase of the second phase, or the nano-phase which can be easily formed through a thermal process.

[0019]Based on this fact, the present invention has made every effort in order to manufacture a neodymium (Nd)-based two-phase amorphous alloy. As a result, a Nd-TM group (TM is a transition element) is formed in which a base element is an element of Nd, a group of A consists of transition elements such as Y, Ti, Zr, La, Pr, Gd, and Hf having a positive heat of mixing relationship with respect to Nd, a group of B consists of transition elements such as Fe and Mn having an excellent glass forming ability together with a high crystallization temperature in a Nd-based amorphous alloy, and a group of C consists of transition elements such as Co, Ni, Cu, and Ag having a negative heat of mixing relationship with respect to Nd. Here, the two-phase separation amorphous alloy can be obtained during solidification by a positive heat of mixing relationship between Nd and the element of the A group in the TM, or between the element of B and the element of C group in the TM.

[0020]For this, the element of TM consists necessarily of any one selected from a combination of an element group among A-B, A-C and B-C, when a group of A consists of a group of elements such as Y, Ti, Zr, La, Pr, Gd and Hf having a positive heat of mixing relationship with respect to Nd, a group of B consists of transition elements such as Fe and Mn enhancing the glass forming ability and increasing the crystallization temperature in a Nd-based amorphous alloy, and a group of C consists of transition elements such as Co, Ni, Cu, and Ag having a negative heat of mixing relationship with respect to Nd, so as to match the purport of the present invention.

[0021]Furthermore, the semi-metal and non-metal elements which are known to contribute to improve the glass forming ability in the Nd-based amorphous alloy are classified as a group of D such as Al, B, Si, and P, to thereby have an excellent glass forming ability after the two-phase separation.

Problems solved by technology

Moreover, The Nd—Fe alloy has the disadvantage that the magnetic property is drastically lowered according to an increase in the temperature.

However, the form of precipitate is being limited to a crystal phase through crystallization of the material inside.

So far, there have been no reports that the magnetic property can be improved by forming an amorphous phase of a second phase.

This means that the compositional range of alloy for obtaining amorphous microstructure is limited.

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