ZIRCONIUM-BASED AMORPHOUS ALLOY AND METHOD FOR PREPARING THE SAME

Abstract

A zirconium-based amorphous alloy, having the following formula: (Zr100-x-yTixHfy)a(CumNin)bAlcMdNe, in which, a, b, c, d, and e represent numbers of atoms, 30≦a≦90, 15≦b≦60, 5≦c≦35, 0.1≦d≦20, 0.1≦e≦5, and a sum of a, b, c, d, and e is 100, x, y, m, and n represent numbers of atoms of Ti, Hf, Cu, and Ni, respectively, and 0≦x≦0.2, 0≦y≦0.05, 0.2≦m/n≦5. M is at least one selected from Y and Sc, and N is at least one selected from Si and C. A crystalline phase accounts for between 5 and 50 v. % of a total volume of the zirconium-based amorphous alloy, and an amorphous phase accounts for between 50 and 95 v. % of the total volume of the zirconium-based amorphous alloy.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of International Patent Application No. PCT/CN2014/084500 with an international filing date of Aug. 15, 2014, designating the United States, now pending, and further claims priority benefits to Chinese Patent Application No. 201310410770.9 filed Sep. 10, 2013. The contents of all of the aforementioned applications, including any intervening amendments thereto, are incorporated herein by reference. Inquiries from the public to applicants or assignees concerning this document or the related applications should be directed to: Matthias Scholl P. C., Attn.: Dr. Matthias Scholl Esq., 245 First Street, 18th Floor, Cambridge, Mass. 02142.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a zirconium-based amorphous alloy and a method for preparing the same.

2. Description of the Related Art

Conventional preparation methods of amorphous alloy pose high requirements for the purity of the raw material and the production conditions, thus increasing the production cost and restricting the application of the amorphous alloy.

SUMMARY OF THE INVENTION

In view of the above-described problems, it is one objective of the invention to provide a zirconium-based amorphous alloy and a method for preparing the same. By adding at least one element of Y and Sc and at least one element of Si and C and controlling the content proportions thereof, the requirements for the purity of the raw material, the vacuum degree of the melting, the oxygen content in the melting atmosphere, and the cooling rate are greatly decreased, and in the meanwhile, the comprehensive performance and the stability of the zirconium-based amorphous alloy are improved.

To achieve the above objective, in accordance with one embodiment of the invention, there is provided a zirconium-based amorphous alloy, having the following formula: (Zr_100-x-yTi_xHf_y)_a(Cu_mNi_n)_bAl_cM_aN_e, in which, a, b, c, d, and e represent numbers of atoms, 30≦a≦90, 15≦b≦60, 5≦c≦35, 0.1≦d≦20, 0.1≦e≦5, and a sum of a, b, c, d, and e is 100; x, y, m, and n represent numbers of atoms of Ti, Hf, Cu, and Ni, respectively, and 0≦x≦0.2, 0≦y≦0.05, 0.2≦m/n≦5. M is at least one selected from Y and Sc, and N is at least one selected from Si and C. A crystalline phase accounts for between 5 and 50 v. % of a total volume of the zirconium-based amorphous alloy, and an amorphous phase accounts for between 50 and 95 v. % of the total volume of the zirconium-based amorphous alloy.

In a class of this embodiment, a, b, c, d, and e represent the numbers of the atoms, 50≦a≦75, 20≦b≦55, 5≦c≦20, 0.1≦d≦10, and 0.1≦e≦2, and the sum of a, b, c, d, and e is 100. x, y, m, and n represent the numbers of atoms of Ti, Hf, Cu, and Ni, respectively, and 0≦x≦0.15, 0≦y≦0.03, and 0.4≦m/n≦4.5. The crystalline phase accounts for between 10 and 25 v. % of the zirconium-based amorphous alloy, and the amorphous phase accounts for between 75 and 90 v. % of the zirconium-based amorphous alloy.

In accordance with another embodiment of the invention, there is provided a method for preparing the zirconium-based amorphous alloy. The method comprises: melting raw materials of the zirconium-based amorphous alloy in the presence of an inert gas or in vacuum, and then cooling and shaping the raw materials. The raw materials of the zirconium-based amorphous alloy comprise: Zr, Ti, Hf, Cu, Ni, Al, M, and N, and an addition of each component enable the formula of the zirconium-based amorphous alloy to satisfy (Zr_100-x-yTi_xHf_y)_a(Cu_mNi_n)_bAl_cM_dN_e.

In a class of this embodiment, the inert gas is at least one selected from the group consisting of helium, neon, argon, krypton, xenon, and radon gas, and a purity of the inert gas is higher than or equal to 94 v. %. The vacuum condition is at a pressure of lower than 1000 pascal which is presented by an absolute pressure. A melting temperature is between 1000 and 3000° C. A melting time is between 0.5 and 10 min.

In a class of this embodiment, the vacuum condition is smaller than 100 pascal. The melting temperature is between 1200 and 2700° C. The melting time is between 2 and 5 min.

In a class of this embodiment, the vacuum condition is between 0.1 and 50 pascal.

Advantages of the zirconium-based amorphous alloy and the method for preparing the same according to embodiments of the invention are summarized as follows:

By adjusting the atomic percentage of each component in the zirconium-based amorphous alloy and by adding non-metallic elements Y and Sc thereto, the preparation requirements of the amorphous alloy can be decreased. In addition, under the same comprehensive performance, the original high requirement on the purity of the raw material is greatly decreased, and a certain amount of impurity elements are allowed to exist in the raw materials. Thus, by properly adjusting the proportions of the non-metallic elements, such as Si and C, in the amorphous alloy, the comprehensive performance of the zirconium-based amorphous alloy cannot be affected; on the contrary, the production cost on the raw materials during the industrialized batch production can be reduced.

The preparation method of the invention is able to produce the zirconium-based amorphous alloy having a critical size of larger than 3 mm. The produced zirconium-based amorphous alloy not only possesses excellent mechanical performance, but also imposes low requirement on the purity of the raw material and the content of the impurity elements. Specifically, it permits existence of less than or equal to 5% (atomic percentage) of metallic impurity elements and less than or equal to 1% (atomic percentage) of non-metallic impurity elements.

DETAILED DESCRIPTION OF THE EMBODIMENTS

For further illustrating the invention, experiments detailing a zirconium-based amorphous alloy and a method for preparing the same are described below. It should be noted that the following examples are intended to describe and not to limit the invention.

A zirconium-based amorphous alloy provided in the invention is having the following formula: (Zr_100-x-yTi_xHf_y)_a(Cu_mNi_n)_bAl_cM_dN_e, in which, a, b, c, d, and e represent numbers of atoms, 30≦a≦90, 15≦b≦60, 5≦c≦35, 0.1≦d≦20, 0.1≦e≦5, and a sum of a, b, c, d, and e is 100; x, y, m, and n represent numbers of atoms of Ti, Hf, Cu, and Ni, respectively, and 0≦x≦0.2, 0≦y≦0.05, 0.2≦m/n≦5. M is at least one selected from Y and Sc, and N is at least one selected from Si and C.

A crystalline phase accounts for between 5 and 50 v. % of a total volume of the zirconium-based amorphous alloy, and an amorphous phase accounts for between 50 and 95 v. % of the total volume of the zirconium-based amorphous alloy.

Preferably, a, b, c, d, and e represent the numbers of the atoms, 50≦a≦75, 20≦b≦55, 5≦c≦20, 0.1≦d≦10, and 0.1≦e≦2, and the sum of a, b, c, d, and e is 100. x, y, m, and n represent the numbers of atoms of Ti, Hf, Cu, and Ni, respectively, and 0≦x≦0.15, 0≦y≦0.03, and 0.4≦m/n≦4.5.

The crystalline phase accounts for between 10 and 25 v. % of the zirconium-based amorphous alloy, and the amorphous phase accounts for between 75 and 90 v. % of the zirconium-based amorphous alloy.

Since the industrialized production generally adopts the much cheaper intermediate alloy as the raw material, the produced zirconium-based amorphous alloy always contains some metallic impurity elements, such as Mg, Ca, and Co, and several non-metallic impurity elements, such as C, O, N, B, and P. But for the zirconium-based amorphous alloy of the invention, existence of a certain amount of impurity elements will not affect the performance of the produced zirconium-based amorphous alloy. For example, taken a total amount of the zirconium-based amorphous alloy as a criteria, the zirconium-based amorphous alloy is allowed to contain less than or equal to 5% (atomic percentage) of the metallic impurity elements and less than or equal to 1% (atomic percentage) of the non-metallic impurity elements. When the contents of the impurities are within the above range, the melting and the preparation of the zirconium-based amorphous alloy will not be affected.

When M is at least one selected from Y and Sc, and N is at least one selected from Si and C, the comprehensive performance of the zirconium-based amorphous alloy is much excellent.

The purities of the raw materials of the zirconium-based amorphous alloy are operable as long as it satisfies the common requirements, and preferable purities thereof are high than 98 wt. %.

In the preparation of the zirconium-based amorphous alloy, the proportion between the crystalline phase and the amorphous phase therein can be adjusted by controlling the composition of the zirconium-based amorphous alloy and controlling the condition for the cooling and shaping according to the common method in the technical field. The condition for the cooling and shaping includes: the cooling rate, the pressure, the material of the die, and the thermal conductivity of the die. The cooling rate is one of the important factors to control proportion of the crystalline phase to the amorphous phase of the zirconium-based amorphous alloy, while the pressure, the material of the die, and the thermal conductivity of the die have a relatively wide selection range, and the cooperative selection thereof can satisfy the condition for the cooling and shaping as along as a proper cooling rate is obtained. In the well-known casting forming methods, the volume percentage of the crystalline phase is generally negatively proportional to the cooling rate. According to the invention, the cooling rate can be selected within the common range, such as higher than 10 K/s, and preferable between 10 and 10⁴ K/s.

In the method for preparing the zirconium-based amorphous alloy of the invention, the inert gas is at least one selected from the group consisting of helium, neon, argon, krypton, xenon, and radon gas, and a purity of the inert gas is higher than or equal to 94 v. %.

The vacuum condition is at a pressure of lower than 1000 pascal which is presented by an absolute pressure.

A melting temperature is between 1000 and 3000° C.

A melting time is between 0.5 and 10 min.

Preferably, the melting time is between 2 and 5 min.

A melting device can be the common melting devices, such as the vacuum arc melting furnace, a vacuum induction furnace, or a vacuum resistance furnace.

The zirconium-based amorphous alloy has excellent shaping performance Thus, the cooling and shaping can adopt the common die-casting methods and the stainless steel and copper alloy materials in the technical filed. The cooling of the die can adopt the water cooling and oil cooling methods.

Example 1

Raw materials having purities of 99 wt. % for the zirconium-based amorphous alloy were added into a vacuum arc melting furnace, the vacuum arc melting furnace was then deaerated until a pressure therein was 10 pascal. After that, argon gas having a purity of 99.9 v. % was introduced into the vacuum arc melting furnace as a protective gas, and the melting was performed at a temperature of 1500° C. for 3 min to make the raw materials for the zirconium-based amorphous alloy fully melted. Components and contents (atomic percentages) of the raw materials for the zirconium-based amorphous alloy were as follows: 50% of Zr, 2% of Ti, 15% of Cu, 10% of Ni, 15% of Al, 4% of Y, 2% of Sc, and 2% of Si.

A melted sample was finally casted into a copper alloy die by a die-casting method for cooling and shaping so as to obtain the zirconium-based amorphous alloy (Zr_100-x-yTi_xHf_y)_a(Cu_mNi_n)_bAl_cM_dN_e.

Example 2

Raw materials having purities of 99 wt. % for the zirconium-based amorphous alloy were added into a vacuum arc melting furnace, the vacuum arc melting furnace was then deaerated until a pressure therein was 10⁻¹ pascal. After that, argon gas having a purity of 99.9 v. % was introduced into the vacuum arc melting furnace as a protective gas, and the melting was performed at a temperature of 1650° C. for 3 min to make the raw materials for the zirconium-based amorphous alloy fully melted. Components and contents (atomic percentages) of the raw materials for the zirconium-based amorphous alloy were as follows: 60% of Zr, 3% of Ti, 2% of Hf, 12.5% of Cu, 7.5% of Ni, 5% of Al, 5% of Y, 3% of Sc, 1.5% of Si, and 0.5% of C.

A melted sample was finally casted into a copper alloy die by a die-casting method for cooling and shaping so as to obtain the zirconium-based amorphous alloy (Zr_100-x-yTi_xHf_y)_a(Cu_mNi_n)_bAl_cM_dN_e.

Example 3

Raw materials having purities of 99 wt. % for the zirconium-based amorphous alloy were added into a vacuum arc melting furnace, the vacuum arc melting furnace was then deaerated until a pressure therein was 10⁻¹ pascal. After that, argon gas having a purity of 99.9 v. % was introduced into the vacuum arc melting furnace as a protective gas, and the melting was performed at a temperature of 1600° C. for 3 min to make the raw materials for the zirconium-based amorphous alloy fully melted. Components and contents (atomic percentages) of the raw materials for the zirconium-based amorphous alloy were as follows: 60% of Zr, 1.5% of Ti, 0.5% of Hf, 10.5% of Cu, 9.5% of Ni, 8% of Al, 0.5% of Y, 1.2% of Sc, and 0.3% of Si.

A melted sample was finally casted into a copper alloy die by a die-casting method for cooling and shaping so as to obtain the zirconium-based amorphous alloy (Zr_100-x-yTi_xHf_y)_a(Cu_mNi_n)_bAl_cM_dN_e.

Example 4

Raw materials having purities of 98 wt. % for the zirconium-based amorphous alloy were added into a vacuum arc melting furnace, the vacuum arc melting furnace was then deaerated until a pressure therein was 200 pascal. After that, argon gas having a purity of 99 v. % was introduced into the vacuum arc melting furnace as a protective gas, and the melting was performed at a temperature of 1500° C. for 3 min to make the raw materials for the zirconium-based amorphous alloy fully melted. Components and contents (atomic percentages) of the raw materials for the zirconium-based amorphous alloy were as follows: 50.5% of Zr, 0.5% of Hf, 30% of Cu, 7.5% of Ni, 10% of Al, 0.8% of Y, and 0.8% of Si.

A melted sample was finally casted into a copper alloy die by a die-casting method for cooling and shaping so as to obtain the zirconium-based amorphous alloy (Zr_100-x-yTi_xHf_y)_a(Cu_mNi_n)_bAl_cM_dN_e.

Example 5

Raw materials having purities of 98 wt. % for the zirconium-based amorphous alloy were added into a vacuum arc melting furnace, the vacuum arc melting furnace was then deaerated until a pressure therein was 50 pascal. After that, argon gas having a purity of 99 v. % was introduced into the vacuum arc melting furnace as a protective gas, and the melting was performed at a temperature of 1600° C. for 3 min to make the raw materials for the zirconium-based amorphous alloy fully melted. Components and contents (atomic percentages) of the raw materials for the zirconium-based amorphous alloy were as follows: 57.5% of Zr, 2.3% of Ti, 1.2% of Hf, 23% of Cu, 6.3% of Ni, 9.2% of Al, 0.2% of Y, and 0.3% of Si.

A melted sample was finally casted into a copper alloy die by a die-casting method for cooling and shaping so as to obtain the zirconium-based amorphous alloy (Zr_100-x-yTi_xHf_y)_a(Cu_mNi_n)_bAl_cM_dN_e.

Comparison Example 1

The preparation of the zirconium-based amorphous alloy is the same as that of Example 1 except that the raw materials for the zirconium-based amorphous alloy have purities of 99.8 wt. %.

Raw materials having purities of 99.8 wt. % for the zirconium-based amorphous alloy were added into a vacuum arc melting furnace, the vacuum arc melting furnace was then deaerated until a pressure therein was 10 pascal. After that, argon gas having a purity of 99.9 v. % was introduced into the vacuum arc melting furnace as a protective gas, and the melting was performed at a temperature of 1500° C. for 3 min to make the raw materials for the zirconium-based amorphous alloy fully melted. Components and contents (atomic percentages) of the raw materials for the zirconium-based amorphous alloy were as follows: 50.9% of Zr, 29.9% of Cu, 7.4% of Ni, 9.8% of Al, and 2% of Y.

Comparison Example 2

Raw materials having purities of 99.7 wt. % for the zirconium-based amorphous alloy were added into a vacuum arc melting furnace, the vacuum arc melting furnace was then deaerated until a pressure therein was 10 pascal. After that, argon gas having a purity of 99.9 v. % was introduced into the vacuum arc melting furnace as a protective gas, and the melting was performed at a temperature of 1800° C. for 3 min to make the raw materials for the zirconium-based amorphous alloy fully melted. Components and contents (atomic percentages) of the raw materials for the zirconium-based amorphous alloy were as follows: 55% of Zr, 2% of Ti, 16.5% of Cu, 13.5% of Ni, 9.6% of Al, 0.4% of Y, and 3% of Nb.

The products were finally detected by metallographic analysis, bending strength test, and oxygen content detection, and detection results are listed in Table 1.

TABLE 1
Parameters of zirconium-based amorphous alloys
prepared by Examples 1-5 and comparison examples 1-2
	Proportion of	Bending strength	Oxygen
	crystalline phase (%)	(megapascal)	content (ppm)
Example 1	23	1970	800
Example 2	20	1890	860
Example 3	22	1785	720
Example 4	12	2170	800
Example 5	15	2035	1000
Comparison	7	1750	1300
example 1
Comparison	5	1600	1450
example 2

It is indicated from Table 1 that according to the components and the contents thereof and the preparation method of the invention, the amorphous alloy that has excellent performance can be acquired under low purity of the raw materials and loosened preparation condition. The amorphous alloy produced in the invention has the proportion of the crystalline phase of between 10 and 25% and the oxygen content of between 600 and 1200 ppm, and has much better mechanical performance compared with the conventional zirconium-based amorphous alloy prepared in the comparison example.

Unless otherwise indicated, the numerical ranges involved in the invention include the end values. While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention.

Claims

1. A zirconium-based amorphous alloy, having the following formula:

(Zr100-x-yTixHfy)a(CumNin)bAlcMdNe

wherein 30≦a≦90, 15≦b≦60, 5≦c≦35, 0.1≦d≦20, 0.1≦e≦5, 0≦x≦0.2, 0≦y≦0.05, 0.2≦m/n≦5, a+b+c+d+e=100, M is at least one selected from Y and Sc, N is at least one selected from Si and C; a crystalline phase accounts for between 5 and 50 vol. % of the total volume of the zirconium-based amorphous alloy, an amorphous phase accounts for between 50 and 95 vol. % of the total volume of the zirconium-based amorphous alloy.

2. The alloy of claim 1, wherein 50≦a≦75, 20≦b≦55, 5≦c≦20, 0.1≦d≦10, 0.1≦e≦2, a+b+c+d+e=100, 0≦x≦0.15, 0≦y≦0.03, 0.4≦m/n≦4.5; the crystalline phase accounts for between 10 and 25 vol. % of the zirconium-based amorphous alloy, and the amorphous phase accounts for between 75 and 90 v. % of the zirconium-based amorphous alloy.

3. A method for preparing the alloy of claim 1, comprising: melting raw materials of the zirconium-based amorphous alloy in the presence of an inert gas or in vacuum, and then cooling and shaping the raw materials; wherein the raw materials of the zirconium-based amorphous alloy comprise: Zr, Ti, Hf, Cu, Ni, Al, M, and N, and an addition of each component enable the formula of the zirconium-based amorphous alloy to satisfy (Zr100-x-yTixHfy)a(CumNin)bAlcMdNe.

4. The method of claim 3, wherein

the inert gas is at least one selected from the group consisting of helium, neon, argon, krypton, xenon, and radon gas, and a purity of the inert gas is higher than or equal to 94 vol. %;

the vacuum is lower than 1000 Pa of absolute pressure;

a melting temperature is between 1000 and 3000oC; and

a melting time is between 0.5 and 10 min.

5. The method of claim 3, wherein the vacuum condition is smaller than 100 pascal; the melting temperature is between 1200 and 2700° C.; and the melting time is between 2 and 5 min.

6. The method of claim 3, wherein the vacuum is between 0.1 and 50 Pa of absolute pressure.