Chromium-based bulk amorphous alloy with high wear resistance and corrosion resistance and preparation method of chromium-based bulk amorphous alloy

Abstract

The invention relates to a chromium-based bulk amorphous alloy with high wear resistance and corrosion resistance and a preparation method of the chromium-based bulk amorphous alloy, and belongs to the field of amorphous alloys. The components of the bulk amorphous alloy meet the relational expression: CraCobMocCdBeLuf, a, b, c, d, e and f represent atomic percentages of elements in an alloy material, 30 < = a < = 50, 13 < = b < = 33, 12 < = c < = 16, 13 < = d < = 17, 4 < = e < = 8, 1 < = f < = 3, and a + b + c + d + e + f = 100. According to the novel chromium-based bulk amorphous alloy, a water-cooling copper mold casting process and industrial-grade raw materials are adopted, and the novel chromium-based bulk amorphous alloy has excellent amorphous forming ability, corrosion resistance and wear resistance and is suitable for various application occasions such as high-strength metal components and corrosion-resistant and wear-resistant coatings.

Description

Technical Field

[0001] The present invention belongs to the field of amorphous alloy materials, and mainly relates to a chromium-based bulk amorphous alloy with high wear and corrosion resistance and a preparation method thereof. Background Art

[0002] The essential difference between amorphous alloys and crystalline alloys lies in the lack of long-range order in their atomic structures. This unique structural feature eliminates common lattice defects (such as dislocations and grain boundaries) in traditional crystalline materials, thereby endowing the materials with excellent mechanical properties, magnetic properties, and chemical stability, specifically manifested as high hardness, high strength, excellent corrosion resistance, and remarkable soft magnetic properties. These characteristics make amorphous alloys a class of new materials with great application prospects.

[0003] Among the many excellent properties, the corrosion resistance of amorphous alloys is particularly prominent, which is mainly attributed to their amorphous structural features. Due to the absence of crystal defects such as grain boundaries and dislocations, the corrosion active sites on the material surface are significantly reduced, and at the same time, a dense and stable oxide passivation layer is easily formed on its surface. In addition, the uniform chemical composition of the material further reduces the sensitivity to local corrosion. A large number of studies have shown that amorphous alloy systems based on elements such as Fe, Ni, Zr, Ti, Cu, and Al all exhibit excellent corrosion resistance, which is mainly due to the formation of a surface protective passivation film. Among these alloy systems, the chromium (Cr) element has attracted much attention for its role in significantly improving the corrosion resistance of materials by promoting the formation of a dense passivation layer.

[0004] Research shows that the corrosion resistance of Cr-containing amorphous alloys is significantly better than that of their crystalline counterparts. As early as 1974, researchers found that Fe 80 Cr 10 P 13 C7 amorphous alloy showed extremely strong corrosion resistance in 1 M HCl solution, while 304 stainless steel corroded severely under the same conditions. Subsequent studies further confirmed the positive effect of the Cr element on the corrosion resistance of amorphous alloys. For example, the Fe-Cr-Mo-C-B bulk metallic glass (BMG) developed by Pang et al. showed excellent tolerance to concentrated hydrochloric acid under high Cr content conditions. The research by Han et al. showed that adding the Cr element to Co-Fe-B-Si amorphous alloy ribbons could significantly improve their corrosion resistance, while slightly reducing the glass-forming ability (GFA).

[0005] However, there are still many mysteries in the research on Cr-based amorphous alloys with high Cr content (>30 at.%). Although high Cr content usually helps to improve corrosion resistance, this effect has a critical threshold. Xu et al. found that Cr x Fe 58.8− x Mo14.7 C 14.7 B 9.8 The corrosion resistance of Y2 (x = 29.4, 36.75, and 44.1 at.%) BMGs in HCl solution increases with the increase of Cr content, but tends to be stable when the Cr content reaches about 29.4 at.%. In addition, Cr developed by Xu et al 50 Fe6Co7Mo 14 C 15 B6Y2 BMG obtained excellent thermal stability, a relatively high glass transition temperature, and excellent corrosion resistance in acidic environments by substituting Fe elements with a high Cr content. Si et al. studied the corrosion behavior of Cr 40 Co 39 Nb7B 14 and Cr 50 Co 29 Nb7B 14 BMG in HCl solution, and the results showed that these alloys could form passivation films in both 1 M and 3 M HCl, and the high Cr content significantly enhanced their passivation performance.

[0006] Based on the above research, the development of bulk amorphous alloys with high Cr content, large amorphous formation ability, excellent thermal stability, mechanical properties, corrosion resistance, and wear resistance not only helps to promote the performance optimization of amorphous alloy coatings, but also lays an important foundation for their industrial applications in extreme wear and corrosion environments. The development of such materials will provide solutions with more excellent performance for related industrial fields, and has important scientific significance and application value. Summary of the Invention

[0007] In view of the above background technology, the purpose of the present invention is to provide a chromium-based bulk amorphous alloy with high wear and corrosion resistance and its preparation method, which is a new type of chromium-based bulk amorphous alloy with excellent wear and corrosion resistance and its preparation method; the chromium-based bulk amorphous alloy has a large amorphous formation ability, good corrosion resistance, and excellent wear resistance.

[0008] To achieve the above purpose, the present invention provides the following technical solutions: A chromium-based bulk amorphous alloy with high wear and corrosion resistance, characterized in that: the composition of the bulk amorphous alloy satisfies the relational expression: Cr a Co b Mo c C d B e Lu f, where a, b, c, d, e, and f represent the atomic percentages of the respective elements in the alloy material, specifically as follows: 30 ≤ a ≤ 50, 13 ≤ b ≤ 33, 12 ≤ c ≤ 16, 13 ≤ d ≤ 17, 4 ≤ e ≤ 8, 1 ≤ f ≤ 3 and a + b + c + d + e + f = 100; the chromium-based bulk amorphous alloy is in an amorphous structure, does not contain any crystalline structure, has a large amorphous formation ability (critical diameter ≥ 3 mm), and the corrosion current density of the chromium-based bulk amorphous alloy in 1 M HCl solution is (1.51 - 31.00)×10 -7 A / cm 2 ; the dry sliding wear rate at room temperature is approximately (0.98 - 3.01)×10 -5 mm 3 ·N -1 ·m -1 。

[0009] As a preferred embodiment of the present invention: the purities of the elements Cr, Co, Mo, Lu, C, and B are not less than 99.5%.

[0010] As a preferred embodiment of the present invention: the chromium-based bulk amorphous alloy is prepared by a water-cooled copper mold preparation technique, wherein the diameter of the alloy rod is not greater than 3 mm.

[0011] The preparation method of the chromium-based bulk amorphous alloy with high wear and corrosion resistance of the present invention is carried out according to the following steps: Step 1: According to the designed alloy composition, convert the atomic percentages of the respective elements in Cr x Co 63-x Mo 14 C 15 B6Lu2 (x = 35, 40, and 45 at.%) into mass percentages, and weigh the corresponding masses of the raw materials using a precision electronic balance.

[0012] Step 2: Put the weighed raw materials into a non-consumable vacuum arc furnace. First, use a vacuum pump to evacuate the vacuum in the furnace cavity to 3.5×10 –3 Pa, and use high-purity argon gas (99.99%) to purge the furnace cavity 2 times, then fill the argon gas to -0.05 Pa to maintain the stability of the furnace atmosphere; then, under the protection of high-purity argon gas, use the high-temperature arc generated by the tungsten electrode to melt the high-purity Ti ingot placed beside the sample to remove the residual oxygen in the furnace cavity; then swing the arc to the copper crucible where the raw material sample is placed, and repeatedly melt the alloy 4 - 5 times to obtain a master alloy ingot.

[0013] Step 3: Crush the prepared homogeneous master alloy into small pieces, and under the protection of high-purity argon gas, use the arc melting copper mold suction casting technique to prepare alloy round bars with different diameters.

[0014] The advantages of the present invention are as follows: (1) The novel wear-resistant and corrosion-resistant chromium-based bulk amorphous alloy prepared by the present invention has a critical diameter of 3 mm; in 1 M HCl solution, it shows a low corrosion current density of (1.51 - 31.00)×10 -7 A·cm -2 , and has good corrosion resistance under extreme acidic conditions; under dry sliding friction conditions, the wear rate is (0.98 - 3.01)×10 -5 mm 3 ·N -1 ·m -1 ; (2) The novel wear-resistant and corrosion-resistant chromium-based bulk amorphous alloy of the present invention adopts the melting process of a vacuum arc furnace, and then uses the rapid solidification technology of a water-cooled copper mold to prepare a bulk amorphous alloy sample rod. The preparation process is simple and easy to implement; (3) The novel wear-resistant and corrosion-resistant chromium-based bulk amorphous alloy of the present invention has good corrosion resistance and wear resistance, and can be applied to the field of wear-resistant and corrosion-resistant coatings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to make the objectives, technical solutions and beneficial effects of the present invention clearer, the present invention will be further described below in conjunction with the drawings and embodiments: Figure 1 X-ray diffraction pattern of the novel chromium-based bulk metallic glass Cr x Co 63-x Mo 14 C 15 B6Lu2 (x = 35, 40, and 45 at.%).

[0016] Figure 2 Thermal analysis curve of the novel chromium-based bulk metallic glass Cr x Co 63-x Mo 14 C 15 B6Lu2 (x = 35, 40, 45 at.%).

[0017] Figure 3 Wear rate test pictures of the novel chromium-based bulk metallic glass Cr x Co 63-x Mo 14 C 15 B6Lu2 (x = 35, 40, 45 at.%).

[0018] Figure 4 Cr x Co 63-x Mo14 C 15 Polarization curves of the new chromium-based bulk metallic glass B6Lu2 (x = 35, 40, 45 at.%). DETAILED DESCRIPTION

[0019] In order to make the purpose, technical scheme and beneficial effects of the present invention clearer, the present invention will be further described in detail below in conjunction with embodiments. The described examples are only part of the embodiments of the present invention and do not represent all the embodiments of the present invention. Example 1

[0020] A chromium-based bulk amorphous alloy material with high wear and corrosion resistance, whose composition satisfies the relationship: Cr a Co b Mo c C d B e Lu f , where a, b, c, d, e and f represent the atomic percentage of each element in the alloy material, wherein 30≤a≤50, 13≤b≤33, 12≤c≤16, 13≤d≤17, 4≤e≤8, 1≤f≤3 and a+b+c+d+e+f =100. Example 2

[0021] A chromium-based bulk amorphous alloy material with high wear and corrosion resistance, specifically Cr 35 Co 28 Mo 14 C 15 B6Lu2 was prepared by the following method: Step 1: Ingredients Calculate and weigh the required pure Cr, pure Co, pure Mo, pure C, pure B and pure Lu with a purity greater than 99.9% according to the composition; Step 2: Melting the master alloy The accurately weighed raw materials are placed in the copper crucible of the non-consumable vacuum arc melting furnace. First, the melting furnace cavity is evacuated. When the vacuum degree reaches 3.5×10 -3 When the pressure is below 0.04 MPa, high-purity argon is filled into the cavity as a protective atmosphere until the pressure rises back to 0.04 MPa. Then the tungsten electrode is moved to the top of the raw material, the arc striking program is started and the electromagnetic stirring device is turned on simultaneously. By precisely adjusting the melting current and controlling the arc heat source intensity, the raw materials are fully melted and uniformly alloyed, and finally a master alloy ingot with uniform composition is obtained; Step 3: Preparation of amorphous alloy The Cr prepared in step 2 35 Co 28 Mo 14 C 15The B6Lu2 master alloy ingot was crushed into small pieces and remelted in a non-consumable vacuum arc melting furnace under the protection of high-purity argon. When the alloy was in a uniform molten state, the suction casting system was quickly started and the arc was simultaneously turned off. The melt was sucked into a water-cooled copper mold by negative pressure, and the suction casting time was controlled at about 5 s. Finally, an alloy round bar with a critical diameter of 2.5 mm was obtained.

[0022] Cr prepared according to Example 2 35 Co 28 Mo 14 C 15 The XRD pattern of the B6Lu2 bulk amorphous alloy round bar sample is as Figure 1 shown. It can be seen that the XRD pattern of the sample shows a broad diffraction peak between 40° and 50°, and no sharp crystalline peaks are observed, indicating that the sample has a completely amorphous structure. And Cr 35 Co 28 Mo 14 C 15 The maximum critical size of the B6Lu2 sample reached 2.5 mm. The thermodynamic parameters of the obtained sample were characterized by differential scanning calorimetry, as Figure 2 shown. The DSC results showed an obvious glass transition, followed by an extended supercooled liquid region and a multi-stage crystallization process. The Cr-based amorphous alloy of this composition exhibited a high T of 933 K g , reflecting the excellent thermal stability of the Cr-based amorphous alloy, which is usually related to the mechanical strength, indicating its excellent wear resistance. The microhardness test and the wear rate of the dry sliding friction and wear test of the prepared chromium-based bulk amorphous alloy sample are as Figure 3 shown. The Vickers microhardness reached 1403 HV 1.0 , and the test results of the reciprocating dry sliding friction and wear test showed that the dry sliding wear rate at room temperature was 0.98×10 -5 mm 3 ·N -1 ·m -1 ; Figure 4 The potentiodynamic polarization curves of the as-cast chromium-based bulk amorphous alloy of Example 2 and 316L stainless steel and Hastelloy in 1 M HCl solution are shown. The corrosion current density of Example 2 was 1.31×10 -6 A·cm -2 . Example 3

[0023] A chromium-based bulk amorphous alloy material with high wear and corrosion resistance, specifically Cr 40 Co 23 Mo 14 C 15 B6Lu2, was prepared by the following method: Step 1: Batching Weigh pure Cr, pure Co, pure Mo, pure C, pure B, and pure Lu with a purity greater than 99.9% according to the composition. Step 2: Melting the master alloy Place the accurately weighed raw materials in a copper crucible of a non-consumable vacuum arc melting furnace. First, evacuate the melting furnace cavity. When the vacuum degree reaches below 3.5×10 -3 Pa, fill the cavity with high-purity argon as a protective atmosphere until the air pressure rises back to 0.04 MPa. Then move the tungsten electrode above the raw materials, start the arc ignition program, and simultaneously turn on the electromagnetic stirring device. By precisely controlling the melting current, control the intensity of the arc heat source to fully melt the raw materials and achieve uniform alloying, ultimately obtaining a master alloy ingot with uniform composition; Step 3: Preparing the amorphous alloy Break the Cr 40 Co 23 Mo 14 C 15 B6Lu2 master alloy ingot prepared in Step 2 into small pieces. Under the protection of high-purity argon, remelt it using a non-consumable vacuum arc melting furnace. When the alloy is in a uniformly molten state, quickly start the suction casting system and simultaneously turn off the arc, and suck the melt into a water-cooled copper mold using negative pressure. Control the suction casting time at about 5 s, ultimately obtaining an alloy round bar with a critical diameter of 3 mm.

[0024] The XRD pattern of the Cr 40 Co 23 Mo 14 C 15 B6Lu2 bulk amorphous alloy round bar sample prepared according to Example 3 is as shown in Figure 1 . It can be seen that the XRD pattern of the sample shows a broad diffraction peak between 40~50°, and no sharp crystalline peaks are observed, indicating that the sample has a completely amorphous structure. And the Cr 40 Co 23 Mo 14 C 15 B6Lu2 sample has a maximum critical size of 3 mm. The thermodynamic parameters of the obtained sample are characterized by differential scanning calorimetry, as shown in Figure 2 . The DSC results show an obvious glass transition, followed by an extended supercooled liquid region and a multi-stage crystallization process. The Cr-based amorphous alloy of this composition exhibits a high T of 946K g , reflecting the excellent thermal stability of the Cr-based amorphous alloy. The microhardness test and dry sliding friction and wear test wear rate of the prepared chromium-based bulk amorphous alloy sample are as shown in Figure 3 . The Vickers microhardness reaches 1440 HV 1.0The reciprocating dry sliding friction and wear test results show that the dry sliding wear rate at room temperature is 1.57×10 -5 mm 3 ·N -1 ·m -1 ; Figure 4 The potentiodynamic polarization curves of the as-cast chromium-based bulk amorphous alloy of Example 3, 316L stainless steel and Hastelloy alloy in 1M HCl solution are shown. The corrosion current density of Example 3 is 3.24×10 -7 A.cm -2 . Example 4

[0025] A chromium-based bulk amorphous alloy material with high wear and corrosion resistance, specifically Cr 45 Co 18 Mo 14 C 15 B6Lu2 was prepared by the following method: Step 1: Ingredients Calculate and weigh the required pure Cr, pure Co, pure Mo, pure C, pure B and pure Lu with a purity greater than 99.9% according to the composition; Step 2: Melting the master alloy The accurately weighed raw materials are placed in the copper crucible of the non-consumable vacuum arc melting furnace. First, the melting furnace cavity is evacuated. When the vacuum degree reaches 3.5×10 -3 When the pressure is below 0.04 MPa, high-purity argon is filled into the cavity as a protective atmosphere until the pressure rises back to 0.04 MPa. Then the tungsten electrode is moved to the top of the raw material, the arc striking program is started and the electromagnetic stirring device is turned on simultaneously. By precisely adjusting the melting current and controlling the arc heat source intensity, the raw materials are fully melted and uniformly alloyed, and finally a master alloy ingot with uniform composition is obtained; Step 3: Preparation of amorphous alloy The Cr prepared in step 2 35 Co 28 Mo 14 C 15 The B6Lu2 master alloy ingot was broken into small pieces and remelted in a non-consumable vacuum arc melting furnace under the protection of high-purity argon. When the alloy was in a uniform molten state, the suction casting system was quickly started and the arc was closed synchronously. The melt was sucked into a water-cooled copper mold using negative pressure. The suction casting time was controlled at about 5 s, and finally an alloy round rod with a critical diameter of 1.5 mm was obtained.

[0026] Cr prepared according to Example 4 45 Co 18 Mo 14 C 15 The XRD spectrum of the B6Lu2 bulk amorphous alloy round rod sample is shown inFigure 1 As shown, the XRD spectrum of the sample shows a broad diffraction peak between 40° and 50°, and no sharp crystalline peaks are observed, indicating that the sample has a completely amorphous structure. Cr 45 Co 18 Mo 14 C 15 The maximum critical size of the B6Lu2 sample reaches 1.5 mm. The thermodynamic parameters of the obtained samples were characterized by differential scanning calorimetry, such as Figure 2 shown. The DSC results show an obvious glass transition, followed by an extended supercooled liquid region and a multi-stage crystallization process. The Cr-based amorphous alloy of this composition exhibits a high T of 960 K g , reflecting the excellent thermal stability of the Cr-based amorphous alloy. The microhardness test and dry sliding friction and wear test wear rate of the prepared chromium-based bulk amorphous alloy samples are as Figure 3 shown. The Vickers microhardness reaches 1520 HV 1.0 , and the test results of the reciprocating dry sliding friction and wear test show that the dry sliding wear rate at room temperature is 3.01×10 -5 mm 3 ·N -1 ·m -1 ; Figure 4 shows the potentiodynamic polarization curves of the as-cast chromium-based bulk amorphous alloy of Example 4 and 316L stainless steel and Hastelloy in 1M HCl solution. The corrosion current density of Example 4 is 1.14×10 -7 A·cm -2 , and its corrosion resistance is the best.

[0027] It can be seen from Figures 1-4 that a kind of chromium-based bulk amorphous alloy with high wear and corrosion resistance mentioned in Examples 1 to 4 has excellent corrosion and wear resistance, and can be widely applied to application fields such as high-strength metal structural parts and corrosion-resistant and wear-resistant coatings.

Claims

1. A chromium-based bulk amorphous alloy with high wear and corrosion resistance, characterized in that: The bulk amorphous alloy composition satisfies the relationship: Cr a Co b Mo c C d B e Lu f , where a, b, c, d, e and f represent the atomic percentage of each element in the alloy material, wherein 30≤a≤50, 13≤b≤33, 12≤c≤16, 13≤d≤17, 4≤e≤8, 1≤f≤3 and a+b+c+d+e+f=100.

2. The chromium-based bulk amorphous alloy with high wear and corrosion resistance according to claim 1, characterized in that: The purity of the Cr, Co, Mo, Lu, B and C elements is not less than 99 wt.%.

3. The chromium-based bulk amorphous alloy with high wear and corrosion resistance according to claim 2, characterized in that: The prepared chromium-based bulk metallic glass has an amorphous structure and does not contain any crystalline structure.

4. The chromium-based bulk amorphous alloy with high wear and corrosion resistance according to claim 2, characterized in that: Amorphous alloy rods with a diameter not exceeding 3 mm were prepared by water-cooled copper mold casting process.

5. The method for preparing the chromium-based bulk amorphous alloy with high wear and corrosion resistance according to claim 1, characterized in that: The following steps are involved: Step 1: According to the designed alloy composition, Cr a Co b Mo c C d B e Lu f The atomic percentage of each element in the mixture is converted into mass percentage, and the corresponding mass of raw materials is weighed using a precision electronic balance; Step 2: Place the weighed raw materials into a non-consumable vacuum arc furnace. First, use a vacuum pump to evacuate the furnace chamber to a vacuum of 3.5×10 –3 Pa, and use high-purity argon (99.99%) to purge the furnace chamber twice, and then fill the argon to -0.05 Pa to keep the atmosphere in the furnace stable; then, under the protection of high-purity argon gas, use the high-temperature arc generated by the tungsten electrode to melt the high-purity Ti ingot placed next to the sample to remove the residual oxygen in the furnace chamber; then throw the arc to the copper crucible where the raw material sample is placed, and repeatedly melt the alloy 4-5 times to obtain the master alloy ingot; Step 3: The prepared master alloy with uniform composition is broken into small pieces, and under the protection of high-purity argon, arc melting copper mold suction casting technology is used to prepare alloy round bars of different diameters.

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