阅读说明：本技术 一种ZrTiHfNbTa高熵合金及其制备方法 (ZrTiHfNbTa high-entropy alloy and preparation method thereof ) 是由 张洋 张中武 蒋文清 商永轩 崔烨 孙利昕 陈丹 于 2019-10-15 设计创作，主要内容包括：本发明属于合金材料及其制备技术领域,具体涉及一种ZrTiHfNbTa高熵合金及其制备方法,目的在于提供一种具有高强度、高延伸率、低弹性模量的ZrTiHfNbTa高熵合金及其制备方法,包含以下步骤：首先按照成分及摩尔百分分数配置原料；再将原料置于铜坩埚内抽真空后冲氩气；最后开始熔炼,在不同的条件下反复熔炼4-10次获得合金铸锭。本发明通过合金元素选择设计了一种新的合金体系,与现有难熔高熵合金相比,使合金的弹性模量降低,力学性能获得显著提升。(The invention belongs to the technical field of alloy materials and preparation thereof, and particularly relates to a ZrTiHfNbTa high-entropy alloy and a preparation method thereof, aiming at providing a ZrTiHfNbTa high-entropy alloy with high strength, high elongation and low elastic modulus and a preparation method thereof, wherein the ZrTiHfNbTa high-entropy alloy comprises the following steps: firstly, preparing raw materials according to components and mole percentage; then placing the raw materials in a copper crucible, vacuumizing and then filling argon; and finally, smelting, and repeatedly smelting for 4-10 times under different conditions to obtain an alloy ingot. According to the invention, a new alloy system is designed through selection of alloy elements, and compared with the existing refractory high-entropy alloy, the elastic modulus of the alloy is reduced, and the mechanical property is obviously improved.)

1. A ZrTiHfNbTa high-entropy alloy is characterized by comprising the following components in percentage by mole: zr5.0-40.0%, Ti5.0-40.0%, Hf5.0-35.0%, Nb5.0-35.0%, Ta5.0-30.0%.

2. The preparation method of the ZrTiHfNbTa high-entropy alloy is characterized by comprising the following steps

The method comprises the following steps: preparing raw materials according to the components and the mol percent of the ZrTiHfNbTa high-entropy alloy, wherein the components and the mol percent of the ZrTiHfNbTa high-entropy alloy comprise: zr5.0-40.0%, Ti5.0-40.0%, Hf5.0-35.0%, Nb5.0-35.0%, Ta5.0-30.0%.

Step two: placing the raw materials in a copper crucible, and vacuumizing until the vacuum degree reaches 10^-2Pa-10^-4Pa, then flushing argon to 0.05 MPa.

Step three: the arc striking current is 50-500A, the first melting current is maintained at 100-200A for smelting for 2-20 minutes, the alloy is turned over after being cooled, magnetic stirring is started from the second smelting, the smelting current is at 400-600A, and the alloy is repeatedly smelted for 4-10 times, so that the alloy ingot is finally obtained.

3. The method for preparing ZrTiHfNbTa high entropy alloy as claimed in claim 2, wherein the purities of Zr, Ti, Hf, Nb and Ta are all more than 99.9%.

4. The method for preparing ZrTiHfNbTa high entropy alloy as claimed in claim 2, wherein the raw materials are placed in the copper crucible from the bottom of the crucible to the top in sequence of Ta, Nb, Hf, Ti, Zr.

Technical Field

The invention belongs to the technical field of alloy materials and preparation thereof, and particularly relates to a ZrTiHfNbTa high-entropy alloy and a preparation method thereof.

Background

The high-entropy alloy breaks through the limitation that one or two elements are the main elements in the traditional alloy, and five or more elements are prepared into a novel alloy according to the content of each element of 5-35%. Because the alloy contains more metal elements and has large element chaos, the solidified alloy can not form a large amount of intermetallic compounds like the traditional alloy, but promotes the mixing among elements because of the high entropy effect, so that the multi-principal-element high entropy alloy forms simple crystalline phase, namely, a plurality of elements are arranged in a disordered way to form body-centered cubic or face-centered cubic phase or even amorphous phase, and simultaneously the formation of brittle intermetallic compounds is inhibited. The characteristic that a single solid solution phase is easy to form enables the high-entropy alloy to show excellent performance, and compared with the traditional alloy, the high-entropy alloy has obvious tissue and performance advantages such as high strength, high hardness, good ductility, high wear resistance and corrosion resistance, high heat resistance, high resistance and the like, so that the high-entropy alloy becomes a new research hotspot after bulk amorphous in the fields of material science and condensed physical, and has attracted general attention and active exploration.

Since the discovery of high-entropy alloys, typical high-entropy alloy systems reported mainly include alloys with face-centered cubic solid solution structures represented by CoCrCuFeNi and discovered by samouria et al, and alloys with body-centered cubic solid solution structures represented by AlCoCrFeNi and discovered by heroic et al. In 2010, the American air force research laboratory Senkov professor and the like firstly develop refractory high-entropy alloy consisting of high-melting-point metal elements such as Hf, Nb, Ta, Mo, W and the like, and the high-entropy alloy has high strength, excellent corrosion resistance, wear resistance and high-temperature oxidation resistance and has good application prospect in biomedicine, aerospace, high-temperature parts and the like.

Despite the previous research on high-entropy alloys, most of the research has focused on alloy systems composed of metals with lower melting points, and some research has focused on combining high-melting-point metals with low-melting-point metals, while the research on refractory high-entropy alloys composed entirely of high-melting-point elements is still less. Compared with the common high-entropy alloy, the refractory high-entropy alloy generally has higher strength and more excellent high-temperature oxidation property, corrosion resistance and the like, but the plasticity is generally poor, for example, the compressive yield strength of the NbCrMo0.5Ta0.5TiZr alloy at room temperature is 1595MPa, but the elongation is only 5%; the compressive yield strength of the MoNbTaW and MoNbTaVW alloy can still reach more than 400MPa at 1600 ℃ and the room-temperature plasticity is poor, and the elongation is lower than 3%. The Podolsky et al, Ukrainian cryophysical engineering research institute, prepares Ti30Zr25Hf15Nb20Ta10 high-entropy alloy, but their compositions and processes are different from the invention, the discharging sequence, the smelting vacuum degree, the smelting current and the time are all different from the invention, especially the invention adopts magnetic stirring to ensure even smelting, while the Podolsky et al does not adopt magnetic stirring when smelting the alloy. 201310593871.4, 201610248764.1, 201710458007.1 and other patents disclose TiZrNbHf, WNbTaMoV, CrMoNbTiZr refractory high entropy alloys and preparation methods thereof, but the element compositions and preparation processes are different from those of the invention. The novel ZrTiHfNbTa high-entropy alloy disclosed by the invention has ultrahigh strength, high plasticity and low elastic modulus.

Disclosure of Invention

The invention aims to provide a ZrTiHfNbTa high-entropy alloy with high strength, high elongation and low elastic modulus. The invention also aims to provide a preparation method of the ZrTiHfNbTa high-entropy alloy with good biocompatibility.

In order to realize the purpose of the invention, the technical scheme is as follows:

a ZrTiHfNbTa high-entropy alloy comprises the following components in percentage by mole: zr5.0-40.0%, Ti5.0-40.0%, Hf5.0-35.0%, Nb5.0-35.0%, Ta5.0-30.0%.

A preparation method of ZrTiHfNbTa high-entropy alloy comprises the following steps

The method comprises the following steps: preparing raw materials according to the components and the mol percent of the ZrTiHfNbTa high-entropy alloy, wherein the components and the mol percent of the ZrTiHfNbTa high-entropy alloy comprise: zr5.0-40.0%, Ti5.0-40.0%, Hf5.0-35.0%, Nb5.0-35.0%, Ta5.0-30.0%.

Step two: placing the raw materials in a copper crucible, and vacuumizing until the vacuum degree reaches 10^-2Pa-10^-4Pa, then flushing argon to 0.05 MPa.

Step three: the arc striking current is 50-500A, the first melting current is maintained at 100-200A for smelting for 2-20 minutes, the alloy is turned over after being cooled, magnetic stirring is started from the second smelting, the smelting current is at 400-600A, and the alloy is repeatedly smelted for 4-10 times, so that the alloy ingot is finally obtained.

The purities of the raw materials Zr, Ti, Hf, Nb and Ta are all more than 99.9%.

The raw materials are placed in the copper crucible, and Ta, Nb, Hf, Ti and Zr are arranged in sequence from the bottom of the crucible to the top.

Compared with the prior art, the invention has the advantages that:

according to the invention, a new alloy system is designed through selection of alloy elements, and compared with the existing refractory high-entropy alloy, the elastic modulus of the alloy is reduced, and the mechanical property is obviously improved.

Drawings

FIG. 1 is a prepared ZrTiHfNbTa high-entropy alloy microstructure;

FIG. 2 is a compressive stress strain curve of the prepared ZrTiHfNbTa high-entropy alloy.

Detailed Description

The present invention is described in further detail below with reference to the attached drawings.

The invention belongs to the technical field of alloy materials and preparation thereof, and particularly relates to a ZrTiHfNbTa high-entropy alloy and a preparation method thereof, aiming at providing a ZrTiHfNbTa high-entropy alloy with high strength, high elongation and low elastic modulus and a preparation method capable of preparing the ZrTiHfNbTa high-entropy alloy with good biocompatibility.

In order to realize the purpose of the invention, the technical scheme is as follows:

a ZrTiHfNbTa high-entropy alloy comprises the following components in percentage by mole: zr5.0-40.0%, Ti5.0-40.0%, Hf5.0-35.0%, Nb5.0-35.0%, Ta5.0-30.0%.

A preparation method of ZrTiHfNbTa high-entropy alloy comprises the following steps

The method comprises the following steps: preparing raw materials according to the components and the mol percent of the ZrTiHfNbTa high-entropy alloy, wherein the components and the mol percent of the ZrTiHfNbTa high-entropy alloy comprise: zr5.0-40.0%, Ti5.0-40.0%, Hf5.0-35.0%, Nb5.0-35.0%, Ta5.0-30.0%.

Step two: the raw materials are placed in a copper crucible, the copper crucible is vacuumized to ensure that the vacuum degree reaches 10 < -2 > Pa to 10 < -4 > Pa, and then argon is filled to 0.05 MPa.

Step three: the arc striking current is 50-500A, the first melting current is maintained at 100-200A for smelting for 2-20 minutes, the alloy is turned over after being cooled, magnetic stirring is started from the second smelting, the smelting current is at 400-600A, and the alloy is repeatedly smelted for 4-10 times, so that the alloy ingot is finally obtained.

The purities of the raw materials Zr, Ti, Hf, Nb and Ta are all more than 99.9%.

The raw materials are placed in the copper crucible, and Ta, Nb, Hf, Ti and Zr are arranged in sequence from the bottom of the crucible to the top.

Further described below:

the ZrTiHfNbTa high-entropy alloy in the embodiment comprises the following chemical components in percentage by mole: 25.0% of Zr, 25.0% of Ti0%, 20.0% of Hf20, 20.0% of Nb and 10.0% of Ta. Weighing Zr, Ti, Hf, Nb and Ta with the purity of more than 99.9%, placing the materials in a copper crucible in the sequence from the bottom to the top, vacuumizing, and filling argon to 0.05MPa after the vacuum degree reaches 10-4 Pa. The melting arc-striking current is 200A, the melting is maintained at 200A for 5-6 minutes for the first time, the alloy is turned over after being cooled, the magnetic stirring is started from the second melting, the melting current is 400-600A, the melting is repeated for 5-6 times, and finally the alloy ingot is obtained. The yield strength at room temperature of the ZrTiHfNbTa high-entropy alloy in the embodiment is 1180MPa, the tensile strength is 3359MPa, the elongation is 61%, and the elastic modulus is 86 GPa.

In summary, the present invention belongs to the technical field of alloy materials and preparation thereof, and particularly relates to a ZrTiHfNbTa high-entropy alloy and a preparation method thereof, and aims to provide a ZrTiHfNbTa high-entropy alloy with high strength, high elongation and low elastic modulus and a preparation method thereof, wherein the ZrTiHfNbTa high-entropy alloy comprises the following steps: firstly, preparing raw materials according to components and mole percentage; then placing the raw materials in a copper crucible, vacuumizing and then filling argon; and finally, smelting, and repeatedly smelting for 4-10 times under different conditions to obtain an alloy ingot. According to the invention, a new alloy system is designed through selection of alloy elements, and compared with the existing refractory high-entropy alloy, the elastic modulus of the alloy is reduced, and the mechanical property is obviously improved.