High-temperature, high-hardness and high-corrosion-resistance amorphous alloy

Abstract

The invention relates to a high-temperature, high-hardness and high-corrosion-resistance amorphous alloy. The component expression of the amorphous alloy is CraCobMocNbdBe, and the component ranges of the elements are as follows: 10 < = a < = 50, 10 < = b < = 30, 21 < = c < = 50, 2 < = d < = 30, 10 < = e < = 30, and a + b + c + d + e = 100. The preparation method of the alloy comprises the following steps: uniformly mixing Cr, Co, Mo, Nb and B according to the component range in an electric arc furnace in an argon atmosphere, smelting, and cooling to obtain a master alloy ingot; and then the sample is placed in a melt-spinning fusion tube with a hole formed in the bottom to be heated to be molten, an amorphous alloy thin strip is prepared through disc type single-roller melt-spinning rapid quenching, and the high-temperature, high-hardness and high-corrosion-resistance amorphous alloy is obtained. The alloy has high glass transition temperature, high microhardness and Young modulus and excellent corrosion resistance.

Description

Technical Field

[0001] The invention belongs to the field of amorphous alloys or metallic glasses, and in particular relates to an amorphous alloy with high temperature, high hardness and high corrosion resistance. Background Art

[0002] In recent years, the exploration of high service temperature has become one of the hot topics in amorphous research. Due to its unique long-range disorder and short-range order atomic structure, amorphous alloys have many excellent properties compared to traditional alloys, such as high strength, hardness and elastic limit. However, these excellent properties are limited to low service temperature. When the working temperature exceeds the glass transition temperature (T g ), the long-range disordered high-energy metastable atomic structure will cross the energy barrier under high-temperature thermal activation, reduce the Gibbs free energy of the system, and transform into a long-range ordered low-energy stable structure, which will undergo significant thermal softening and reduce its excellent performance, thus limiting its application in the engineering field. g The level of γ largely determines the upper limit of the service temperature of amorphous alloys. A lot of research has been done on improving the service temperature of amorphous alloys.

[0003] The elastic modulus and melting temperature of the constituent elements of amorphous alloys have an influence on their T g In order to design a high-temperature amorphous alloy with good comprehensive performance, the present invention first selects two main elements of Cr and Mo with low cost, high melting point and high corrosion resistance. Secondly, high hardness Co is added as the main element to ensure the high T g The sample also has excellent mechanical properties. At the same time, considering the strong interaction between metal and metalloid elements, adding metalloid B elements with small atomic size and large negative mixing enthalpy with other elements can not only increase the forming ability of amorphous alloys but also improve their mechanical properties, which is also beneficial to T g Finally, through the ternary Cr-Nb-Mo homogeneous crystal property, a small amount of high melting point and large size Nb element was reasonably added to increase the disorder of atomic arrangement and the probability of forming amorphous alloy. Finally, a series of new high temperature, high hardness and high corrosion resistance Cr-Mo-Co-Nb-B amorphous alloys were designed. Summary of the invention

[0004] The purpose of the present invention is to develop a series of new high-temperature, high-hardness and high-corrosion-resistant amorphous alloys.

[0005] The present invention provides a high-temperature, high-hardness and high-corrosion-resistant amorphous alloy, characterized in that the composition of the amorphous alloy is: Cr a Co b Mo c Nb d B e, where a, b, c, d, e are atomic percentages, 10≤a≤50, 10≤b≤30, 21≤c≤50, 2≤d≤30, 10≤e≤30, a+b+c+d+e=100.

[0006] The preparation method of the present invention is as follows:

[0007] 1) Ingredients: accurately weigh Cr, Co, Mo, Nb, and B with a purity of not less than 99.9% on a balance (accuracy 0.0001g);

[0008] 2) Ingot casting: accurately weigh Cr, Co, Mo, Nb, and B in an electric arc furnace under an argon atmosphere, mix the raw materials in 1) evenly, melt, and cool to obtain an alloy mother ingot.

[0009] 3) Strip spinning: The sample is heated to melt in a strip spinning melting tube with a hole at the bottom, and then a thin amorphous alloy strip (thickness of about 40 μm) is prepared by rapid quenching using a disc-type single-roller strip spinning to obtain a high-temperature, high-hardness and high-corrosion-resistant amorphous alloy of the present invention.

[0010] The high temperature, high hardness and high corrosion resistance amorphous alloy provided by the present invention has an ultra-high glass service temperature and extremely excellent thermodynamic stability. g ) is between 1029K and 1058K, and the crystallization temperature (T x ) at 1097K~1132K, supercooled liquid region (ΔT x ) at 61K~103K. The alloy system has excellent mechanical properties and corrosion resistance, nanohardness and Young's modulus are as high as 18.1GPa and 267GPa respectively, and the self-corrosion current in 1M hydrochloric acid solution is 2.1×10 -6 A / cm 2 . BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 are five kinds of amorphous alloys prepared in Examples 1-5 of the present invention, Cr 27.5 Co 27.5 Mo 26.5 Nb 3.5 B 15 Cr 26.5 Co 26.5 Mo 26.5 Nb 5.5 B 15 Cr 26 Co 26 Mo 26 7B 15 Cr 26.5 Co 25.5 Mo 25.5 Nb5.5 B 17 Cr 26.5 Co 24.5 Mo 26.5 Nb 7.5 B 15 X-ray diffraction pattern of

[0012] Figure 2 are five kinds of amorphous alloys prepared in Examples 1-5 of the present invention, Cr 27.5 Co 27.5 Mo 26.5 Nb 3.5 B 15 Cr 26.5 Co 26.5 Mo 26.5 Nb 5.5 B 15 Cr 26 Co 26 Mo 26 7B 15 Cr 26.5 Co 25.5 Mo 25.5 Nb 5.5 B 17 Cr 26.5 Co 24.5 Mo 26.5 Nb 7.5 B 15 Differential scanning calorimetry (DSC) curve (heating rate is 20K / min); Figure 3 are five kinds of amorphous alloys prepared in Examples 1-5 of the present invention, Cr 27.5 Co 27.5 Mo 26.5 Nb 3.5 B 15 Cr 26.5 Co 26.5 Mo 26.5 Nb 5.5 B 15 Cr 26 Co 26 Mo 26 7B 15 Cr 26.5 Co 25.5 Mo 25.5 Nb 5.5 B 17 Cr 26.5 Co 24.5 Mo 26.5 Nb 7.5 B 15 Potential kinetic polarization curve. DETAILED DESCRIPTION

[0013] The present invention is specifically described below from three aspects: preparation, performance and structure of the alloy.

[0014] 1. Preparation of amorphous alloys

[0015] The Cr used in the present invention a Co b Mo c Nb d B e Amorphous preparation solutions include:

[0016] (1) According to the chemical composition Cr a Co b Mo c Nb d B e , accurately configure the alloy raw materials. The composition characteristics are: 26≤a≤

[0017] 27.5, 24.5≤b≤27.5, 25.5≤c≤26.5, 3.5≤d≤7.5, 15≤e≤17, a+b+c+d+e=100.

[0018] (2) grinding away the oxide layer on the surface of the metal raw material, accurately weighing and proportioning the raw material according to atomic percentage, and using anhydrous ethanol to ultrasonically clean the raw material;

[0019] (3) Use vacuum non-consumable tungsten electrode arc to melt the alloy, and evacuate the furnace to a vacuum degree of less than or equal to 5*10 - 3 Pa, fill with pure argon until the pressure inside the furnace reaches 0.4 to 0.5 atmospheres, repeat this process (i.e., gas washing) at least 3 times;

[0020] (4) Fully melt the alloy 3 to 5 times to ensure uniform melting of the alloy;

[0021] (5) After the alloy is smelted, the oxide layer is polished off, and an appropriate amount of the alloy is taken for ultrasonic cleaning. The alloy sample is placed in a belt spinning melting tube with a hole at the bottom and heated until it melts. Subsequently, a disk-type single-roll belt spinning is used for rapid quenching to prepare an amorphous alloy thin strip, thereby obtaining a high-temperature, high-hardness, and high-corrosion-resistant amorphous alloy of the present invention.

[0022] 2. Properties of amorphous alloys

[0023] Table 1 shows the composition, forming ability, thermodynamic properties, and mechanical performance parameters of a high-temperature and high-corrosion-resistant amorphous alloy of Examples 1-5.

[0024] 1) X-ray diffraction (XRD) test

[0025] The phase composition of the samples was analyzed using an X-ray diffractometer, and the samples were tested using a Cu target X-ray diffraction device. Figure 1 The X-ray diffraction patterns of Examples 1 to 5 are shown. The five curves show broad diffuse peaks that are unique to amorphous materials, indicating that the tested samples are all amorphous. Table 1 shows the forming capabilities of the amorphous alloys of Examples 1 to 5.

[0026] 2) Differential Scanning Calorimetry (DSC) Analysis

[0027] The thermodynamic properties of the amorphous alloy samples were analyzed using a differential scanning calorimeter with a heating rate of 20 K / min and a heating range of 300 K-1700 K.

[0028] Figure 2 The DSC curves of the alloy samples in Examples 1-5 are shown, and it can be seen that each alloy has an obvious glass transition temperature (T g ), crystallization start temperature (T x ), melting point (T m ), liquidus temperature (T l ). The glass transition temperatures of Examples 1-5 are all higher than 1029K, and the T g As high as 1058 K. The specific characteristic temperature values ​​of Examples 1-5 are given in Table 1.

[0029] 3) Mechanical properties

[0030] The microhardness (H) of the alloys in Examples 1-5 was measured by nanoindentation test. N ) are all higher than 16.4 GPa, and the elastic modulus (E) are all higher than 246 GPa. The specific values ​​are given in Table 1.

[0031] 4) Corrosion performance

[0032] Figure 3 The potential kinetic polarization curves of the alloys of Examples 1-5 after being immersed in 1M hydrochloric acid for 120 minutes are shown. We can see that the self-corrosion current density of all components is less than 5×10 -6 A / cm 2 , the corrosion voltage is greater than 0.15 V. Among them, the corrosion resistance of Example 3 is the best, and its self-corrosion current density is 2.96×10 -6 A / cm 2 , the self-corrosion voltage is 0.64V.

[0033] Table 1. Composition, thermodynamic properties, and mechanical performance parameters of the high-temperature, high-hardness, and high-corrosion-resistant amorphous alloy provided by the present invention

[0034]

[0035] Note: 1) The meanings of the symbols in the table are as follows: T g : Glass transition temperature; T x: Crystallization start temperature; T m : Melting point; T l : liquidus temperature; E: elastic modulus; H N : Microhardness.

Claims

1. A high temperature, high hardness and high corrosion resistance amorphous alloy, characterized in that: The composition of the amorphous alloy is: Cr a Co b Mo c Nb d B e , where a, b, c, d, e are atomic percentages, 10≤a≤50, 10≤b≤30, 21≤c≤50, 2≤d≤30, 10≤e≤30, a+b+c+d+e=100.

2. A high-temperature, high-hardness, and high-corrosion-resistant amorphous alloy, characterized in that: The composition of the amorphous alloy is: Cr a Co b Mo c Nb d B e , where a, b, c, d, e are atomic percentages, 24≤a≤35, 20≤b≤27.5, 21≤c≤35, 3≤d≤7.5, 13≤e≤17, a+b+c+d+e=100.

3. A high-temperature, high-hardness, and high-corrosion-resistant amorphous alloy, characterized in that: The composition of the amorphous alloy is: Cr a Co b Mo c Nb d B e , where a, b, c, d, e are atomic percentages, 26≤a≤27.5, 24.5≤b≤27.5, 25.5≤c≤26.5, 3.5≤d≤7.5, 15≤e≤17, a+b+c+d+e=100.

4. A high temperature, high hardness and high corrosion resistance amorphous alloy according to claim 1, wherein, by atomic percentage, Cr a Co b Mo c Nb d B 15 .The alloy composition range is: 26.5≤a≤27.5, 24.5≤b≤27.5, 25.5≤c≤26.5, 3.5≤d≤7.5, e=15, a+b+c+d+e=100.

5. A high temperature, high hardness and high corrosion resistance amorphous alloy according to claim 1, wherein, by atomic percentage, Cr 26 Co 26 Mo 26 7B 15。 6. The preparation method of the high-temperature, high-hardness and high-corrosion-resistant amorphous alloy according to claim 1 is as follows: 1) Ingredients: accurately weigh Cr, Co, Mo, Nb, and B with a purity of not less than 99.9% on a balance (accuracy 0.0001g); 2) Ingot casting: accurately weigh Cr, Co, Mo, Nb, and B in an electric arc furnace under an argon atmosphere, mix the raw materials in 1) evenly, melt, and cool to obtain an alloy mother ingot. 3) Strip spinning: The sample is placed in a strip spinning melting tube with a hole at the bottom and heated until it melts. Then, a disc-type single-roller strip spinning method is used for rapid quenching to prepare an amorphous alloy thin strip, thereby obtaining a high-temperature, high-hardness, and high-corrosion-resistant amorphous alloy of the present invention.

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