Preparation method of zirconium alloy material with oxide ceramic layer modified in situ on surface

Abstract

The invention provides a preparation method of a zirconium alloy material with an oxide ceramic layer modified in situ on the surface, and the preparation method comprises the following steps: carrying out grinding and polishing treatment on a zirconium alloy sample, and carrying out ion implantation on the zirconium alloy sample under a vacuum condition by taking metal zirconium as an ion implantation source; and after the ion implantation is finished, carrying out thermal oxidation treatment on the zirconium alloy sample in an air atmosphere to obtain the zirconium alloy material of the in-situ modified zirconium oxide ceramic layer. The zirconium oxide ceramic layer grows from the surface of the injected zirconium alloy, no obvious interface exists between the zirconium oxide modified layer and a matrix, the bonding strength is high, and the problem that the zirconium oxide layer is peeled off does not need to be worried about; thermal oxidation process parameters are simple and easy to control, and post-treatment is not needed, so that the preparation method is simple and low in preparation cost, and has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the field of surface modification engineering technology, and in particular to a method for preparing a zirconium alloy material having an oxide ceramic layer in situ modified on the surface Background Art

[0002] The thermal neutron absorption cross section of zirconium (Zr) is about 0.18×10 -28 m 2 , second only to Be and Mg, but zirconium also has better mechanical and corrosion properties than Be and Mg, so it is an ideal nuclear structural material and plays an important role in the development of nuclear industry materials. It is known as the "first metal of the atomic age". Over the past decades, due to the excellent specific strength, mechanical properties, corrosion resistance and bioaffinity of zirconium and zirconium alloys, the application of zirconium alloys has gradually achieved industrialization and civilian use. At present, zirconium alloys have been widely used in aerospace, biomedicine, marine engineering, petrochemical and other fields.

[0003] However, the surface hardness of Zr alloy is low and the wear resistance is poor, which makes it difficult to meet the high hardness and wear resistance requirements of key components in various application scenarios in the future. Therefore, surface treatment of Zr alloy surface is an important solution to improve the surface performance of Zr alloy and extend its service life. The preparation of surface hard coating can improve its surface performance, but conventional hard coatings such as TiN, CrN, TiAlN and other coatings will introduce new components; the preparation of ZrN, ZrO 2 Zirconium-based ceramic coatings will introduce a new coating-substrate interface, resulting in the problem of coating peeling and failure; prefabricated oxide ceramic modified layers on the surface of zirconium alloys through thermal oxidation technology will have problems such as low surface zirconium concentration, insufficient purity of the zirconia ceramic layer, and difficult to control thickness.

[0004] For example: CN201810454617.9 discloses a method for preparing a black ceramic layer on the surface of a zirconium-based alloy. The method is simple, and the prepared black zirconium oxide ceramic layer has uniform composition and thickness, dense structure, high hardness, and the surface hardness of the prepared black ceramic layer reaches 519HV. The zirconium alloy involved in this method is an industrial-grade zirconium alloy containing hafnium (Hf). The composition of the oxide ceramic layer is complex and uncontrollable, and its scope of use is limited. CN201910173412.8 discloses a method and application for preparing an oxide ceramic layer on the surface of zirconium and zirconium alloys. The surface roughness is controlled before the surface oxidation treatment, and the inert gas replacement is performed after the surface oxidation treatment to avoid the formation of a film layer with poor performance that needs to be removed during the cooling process, thereby maintaining the integrity and uniformity of the oxide ceramic layer and ensuring its protective performance. However, the preparation process in the above two patent applications is relatively complicated and the preparation cycle is long, and an oxidizing atmosphere needs to be introduced in at least one of the steps of heating, heat preservation or furnace cooling; in the actual processing process, the furnace cooling time is long, and it takes more than 5-6 hours to cool down the furnace to room temperature. The resulting zirconia ceramic layer is relatively thin, and its surface properties, such as surface hardness, are relatively low. In addition, the obtained zirconia ceramic layer needs post-processing to achieve the surface roughness requirements, which increases the preparation cost.

[0005] CN201710158058.2 discloses a fast and low-cost preparation method for black zirconia ceramics. The prepared black zirconia ceramics are block materials, the process is relatively complex and the preparation cycle is long, and it is not a surface modification technology. CN202210807663.9 discloses a method for quickly preparing a ceramic modified layer on the surface of a zirconium alloy, which solves the problems of poor wear resistance, poor compatibility, poor corrosion resistance of medical zirconium alloys and complex preparation process of zirconium alloy modified layers. However, this method is quenched under high temperature conditions, and cracking is easily caused due to the difference in thermal expansion coefficients between the two, and the thickness of the generated ceramic layer is uneven. In addition, in the preparation method, the surface composition of the zirconium alloy is consistent with the internal composition, and the generation of the surface zirconia ceramic layer can only be regulated by a thermal oxidation process, and the purity and thickness of the zirconium oxide layer cannot be optimized by optimizing the surface composition of the zirconium alloy.

[0006] In addition, CN201110183452.4 proposes a method for controlling the thickness of oxide film by ion implantation, and proposes to use different energy doses to control the depth of amorphization of thick gate oxide regions on the surface of silicon wafers, thereby controlling the oxide thickness. This method can use ion implantation doses to control the oxide thickness on the surface of silicon wafers, but it is only for silicon wafers and cannot obtain a zirconium oxide ceramic layer with excellent performance.

[0007] Therefore, there is an urgent need in the art for a new preparation method to solve the problems of zirconia ceramic layer peeling failure, insufficient purity or difficult to control thickness. Summary of the invention

[0008] In view of the shortcomings of the prior art, the present invention aims to provide a method for preparing a zirconium alloy material with an in-situ modified oxide ceramic layer on the surface.

[0009] To achieve this object, the present invention adopts the following technical solutions:

[0010] In a first aspect, the present invention provides a method for preparing a zirconium alloy material with an in-situ modified oxide ceramic layer on its surface, the preparation method comprising the following steps:

[0011] The zirconium alloy sample is subjected to grinding and polishing treatment, and then ion implantation is performed on the zirconium alloy sample under vacuum conditions using metal zirconium as an ion implantation source; after the ion implantation is completed, the zirconium alloy sample is subjected to thermal oxidation treatment in an air atmosphere to obtain a zirconium alloy material with an in-situ modified zirconium oxide ceramic layer.

[0012] The ion implantation and thermal oxidation described in the present invention are two relatively independent and mature technologies, each with independent application fields. Ion implantation is suitable for improving the surface hardness, wear resistance, corrosion resistance, etc. of materials, especially in the fields of semiconductors, aerospace, etc. Thermal oxidation technology has long been used to generate a protective oxide layer on the metal surface to improve the high temperature resistance and corrosion resistance of the material.

[0013] However, ion implantation is usually performed at lower temperatures, while thermal oxidation requires higher temperatures. The difference in temperature control between the two also means that their combined application has not been widely explored in the past.

[0014] The present invention uses a high-voltage electric field to accelerate the ionized Zr metal element to sufficient kinetic energy and inject it into a certain depth range on the surface of the zirconium alloy substrate, thereby changing the surface and subsurface components of the zirconium alloy and increasing the surface concentration of the Zr element. After high-temperature thermal oxidation treatment, the oxygen elements in the atmosphere undergo a process of contact collision, adsorption, decomposition, diffusion, maturation, and growth under high-temperature conditions, and a zirconium-based oxide ceramic layer is generated in situ on the surface of the substrate. There is an oxygen-rich diffusion layer between the ceramic layer and the substrate, and there is no risk of peeling.

[0015] As the concentration of Zr element on the surface of zirconium alloy increases, the generated zirconium oxide ceramic phase purity is higher, more dense and stable. At the same time, due to the blocking effect of the dense zirconium oxide layer on the surface, it is difficult for oxygen to diffuse excessively into the zirconium alloy matrix, so the thickness of the generated zirconium oxide ceramic layer is controllable. The zirconium alloy material obtained by the present invention has a zirconium element injection depth that is less than the thickness of the zirconium oxide ceramic layer. At the same time, the order of ion implantation and thermal oxidation technology cannot be reversed, otherwise the ZrO ceramic layer cannot be generated. The technology provided by the present invention enables ion implantation and thermal oxidation to cooperate with each other and act together on the surface of the zirconium alloy, so that the product performance is comprehensively improved, which not only retains the excellent surface strengthening effect brought by ion implantation, but also utilizes thermal oxidation to generate a high temperature resistant and corrosion resistant zirconium oxide layer to form multiple protections.

[0016] In addition, the present invention selects Zr as the ion implantation source to form ZrO on the surface of the material. 2 Ceramic layer, if other ions such as nitrogen (N), carbon (C), boron (B) are selected, they may compete with oxygen to form other compounds (such as nitrides, carbides or borides), thereby preventing oxygen from combining with zirconium to form ZrO 2 , or a layer of non-oxidizable complex may be formed on the surface to prevent oxygen from diffusing into the zirconium matrix. At the same time, the injected ions may also undergo complex competitive reactions with zirconium or oxygen during thermal oxidation. For example, when N is injected, Zr first combines with N to form ZrN, and the formation of zirconium oxide requires oxygen to penetrate the ZrN layer. In this case, ZrN may act as a diffusion barrier to hinder the diffusion of ZrO 2 form.

[0017] In the present invention, after ion implantation of the Zr element, the Zr concentration on the surface of the zirconium alloy increases, so the generated zirconium oxide ceramic has higher phase purity, is more dense and stable. At the same time, due to the blocking effect of the dense zirconium oxide layer on the surface, it is difficult for oxygen to diffuse excessively into the zirconium alloy matrix, so the thickness of the generated zirconium oxide ceramic layer is controllable.

[0018] As a preferred technical solution of the present invention, the surface roughness (Ra) of the zirconium alloy sample obtained after the grinding and polishing treatment is ≤1 μm. For example, it can be 1 μm, 0.9 μm, 0.8 μm, 0.6 μm, 0.5 μm, 0.4 μm, 0.3 μm, 0.2 μm, 0.1 μm, 0.09 μm, 0.08 μm, 0.07 μm, 0.06 μm, 0.05 μm, 0.04 μm, 0.03 μm, 0.02 μm or 0.01 μm, etc.

[0019] In the present invention, the lower the roughness of the zirconium alloy material, the more obvious the effect of ion implantation and oxidation process on the performance improvement of the zirconium alloy substrate. Taking into account the polishing difficulty and polishing cost of the zirconium alloy material, the present invention sets the lower limit of the roughness of the zirconium alloy material used to 0.05 μm, so the surface roughness of the zirconium alloy sample is preferably 1 μm-0.02 μm.

[0020] Preferably, the grinding and polishing process also includes cleaning and drying operations.

[0021] As a preferred technical solution of the present invention, the cleaning is ultrasonic cleaning, and the ultrasonic cleaning is performed using any one of acetone, deionized water or anhydrous ethanol, or two or more reagents.

[0022] Preferably, the drying method is air drying.

[0023] As a preferred technical solution of the present invention, the parameters of the ion implantation are set as follows: suppression voltage 0.9-1.1 kV, suppression current 0.1-2 mA, extraction voltage 45-50 kV, extraction current ≤5 mA, workpiece target current ≤4 mA;

[0024] Among them, the suppression voltage is 0.9~1.1kV, for example, it can be 0.9kV, 0.95kV, 1kV, 1.05kV, 1.1kV, etc.; the suppression current is 0.1~2mA, for example, it can be 0.1mA, 0.2mA, 0.4mA, 0.5mA, 0.6mA, 0.8mA, 1mA, 1.2mA, 1.5mA, 1.6mA, 1.8mA, 2mA, etc.

[0025] The lead voltage is 45-50kV, for example, it can be 45kV, 45.5kV, 46kV, 46.5kV, 47kV, 47.5kV, 48kV, 48.5kV, 49kV, 49.5kV, 50kV, etc.; the lead current is ≤5mA, for example, it can be 5mA, 4mA, 3mA, 2mA, 1mA, etc.

[0026] The workpiece target current is ≤4mA, for example, it can be 4mA, 3mA, 2mA, 1mA, etc.

[0027] Preferably, the ion implantation time is 30 to 180 min, for example, it may be 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min, 70 min, 80 min, 90 min, 100 min, 120 min, 150 min or 180 min.

[0028] As a preferred technical solution of the present invention, the vacuum degree of the vacuum condition is 3.0×10 -3 ~6.0×10 -4 Pa.

[0029] Preferably, the sample injection surface forms an angle of 60-120° with the ion injection tube, for example, it can be 60°, 65°, 70°, 75°, 80°, 85°, 90°, 95°, 100°, 105°, 110°, 115° or 120°.

[0030] Preferably, the rotation speed of the sample is 5 to 10 r / minn, for example, it can be 5 r / min, 6 r / min, 7 r / min, 8 r / min, 9 r / min, 10 r / min, etc.

[0031] The parameter range of the thermal oxidation process in the present invention is relatively flexible, and changes in the thermal oxidation process will not substantially affect its performance. The main reasons are: the present invention controls the injection depth to be less than the thickness of the zirconium oxide modified layer, and the injection of Zr significantly increases the surface reaction activity, so that the oxidation reaction is concentrated in the injection layer area, while the amount of Zr in the matrix participating in the oxidation reaction is limited.

[0032] On the other hand, the zirconium oxide layer preferentially generated on the surface after Zr injection is more dense, which greatly limits the diffusion of oxygen and zirconium ions inward. As the layer thickness increases, the diffusion resistance increases nonlinearly, and the oxidation reaction gradually slows down. In addition, when the oxide layer grows to close to the injection depth, the diffusion path of Zr to the surface is lengthened, and the diffusion path of surface oxygen inward is also lengthened, the diffusion rate is reduced, and the oxidation reaction gradually slows down until it stops.

[0033] Although the thermal oxidation process parameters of the present application are relatively flexible, in order to obtain better purity and thickness, the heating rate of the thermal oxidation described in the present invention is preferably 1-10°C / min, for example, it can be 1°C / min, 2°C / min, 3°C / min, 4°C / min, 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min, 10°C / min, etc.

[0034] Preferably, the insulation temperature of the thermal oxidation is 450-650°C, for example, it can be 450°C, 480°C, 500°C, 520°C, 550°C, 560°C, 580°C, 600°C, 610°C, 620°C, 630°C, 640°C, 650°C, etc., and the insulation time is 150-400min, for example, it can be 150min, 160min, 180min, 200min, 220min, 240min, 250min, 260min, 280min, 300min, 320min, 350min, 360min, 370min, 380min, 390min, 400min, etc.

[0035] Compared with the case where ion implantation is not performed, the thickness of the layer can be controlled between 4 and 8 μm. If zirconium ion implantation is not performed, the oxidation reaction completely depends on the diffusion of the matrix Zr, and the layer thickness is uneven and difficult to guarantee.

[0036] As a preferred technical solution of the present invention, the thermal oxidation is carried out under normal pressure.

[0037] The thermal oxidation step in the present invention can be completed in an air atmosphere. Zr alloys are mainly composed of zirconium, which has a high oxygen affinity. They can also form a dense zirconium oxide layer under a relatively low oxygen partial pressure (such as an air environment). Zr can be quickly oxidized to form ZrO in an air environment (oxygen content of about 21%). 2Due to the high oxidation activity of zirconium, even at low oxygen concentrations, the generated ZrO 2 The layer is still dense and stable, meeting most engineering requirements.

[0038] The technology relates to a preparation method that does not require post-processing and can directly produce a zirconium oxide ceramic layer. Compared with the traditional method of producing a zirconium oxide ceramic layer by high-temperature oxidation, the present invention produces a thicker zirconium oxide ceramic layer by high-temperature instantaneous oxidation.

[0039] In a second aspect, a zirconium alloy material is prepared using the preparation method described in the first aspect.

[0040] In a third aspect, the use of the preparation method as described in the first aspect or the zirconium alloy material as described in the second aspect in the preparation of aerospace equipment, marine equipment or medical materials.

[0041] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] (1) The zirconium alloy sample described in the present invention is not limited to industrial grade or atomic grade zirconium alloy grades. By ion implanting the Zr element, the concentration of Zr on the surface of the Zr alloy is increased, and the purity and thickness of the zirconium oxide modified layer prepared in situ on the surface of the Zr alloy are improved; at the same time, the injection layer depth of the present method is less than the thickness of the zirconium oxide modified layer, and the zirconium oxide layer preferentially generated on the surface is denser, which can block the continuous diffusion of oxygen elements during the thermal oxidation process. Regardless of how the thermal oxidation process is changed, the thickness of the zirconium oxide modified layer can be controlled between 4-8μm; the substrate is still a metal substrate, and the zirconium oxide ceramic layer is grown from the surface of the zirconium alloy after injection. There is no obvious interface between the zirconium oxide modified layer and the substrate, and the bonding strength is high, so there is no need to worry about the zirconium oxide layer peeling off;

[0044] (2) The preparation process provided by the present invention is simple and has low preparation cost, but the technical innovation is high. After the zirconium alloy is surface ion implanted, it can be thermally oxidized in the process of slowly heating up and slowly cooling down. There is no need to worry about the ceramic layer cracking due to the difference in thermal expansion coefficient between the zirconium oxide ceramic layer and the substrate after high temperature and extreme cooling; and the thermal oxidation process only needs to be carried out in an air atmosphere, without special requirements for oxidation atmosphere concentration, ventilation pressure, ventilation flow rate, etc., and the thermal oxidation process parameters are simple and easy to control. At the same time, the preparation method involved in this technology does not require post-processing (polishing, cleaning and other processes), and the zirconium oxide ceramic layer can be directly obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 Schematic diagram of the structure after a zirconium oxide ceramic layer is in situ generated on the surface of a zirconium alloy sample; 1 is the zirconium oxide ceramic layer, 2 is the oxygen-rich diffusion layer, 3 is the zirconium element injection layer, and 4 is the zirconium alloy matrix.

[0046] Figure 2 These are photos of the Zr alloy substrate and the surfaces of samples of Examples 1 to 3, wherein Figure I is the Zr alloy substrate, Figure II is Example 1, Figure III is Example 2, and Figure IV is Example 3.

[0047] Figure 3 The micrograph of the zirconium oxide ceramic layer produced in Example 1 shows the result.

[0048] Figure 4 The micrograph of the zirconium oxide ceramic layer produced in Example 2 shows the result.

[0049] Figure 5 The micrograph of the zirconium oxide ceramic layer produced in Example 3 shows the result.

[0050] Figure 6 This is a micrograph showing the zirconium oxide ceramic layer generated by direct thermal oxidation of the zirconium alloy substrate without ion implantation.

[0051] Figure 7 The XRD phase analysis results of the Zr alloy substrate and Examples 1 to 3 are shown in Figure I, Figure II is Example 1, Figure III is Example 2, and Figure IV is Example 3. DETAILED DESCRIPTION

[0052] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and through specific implementation methods. However, the following examples are only simple examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0053] In the following examples, unless otherwise specified, all reagents and consumables used were purchased from conventional reagent manufacturers in the field; unless otherwise specified, all experimental methods and technical means used were conventional methods and means in the field.

[0054] A zirconium oxide ceramic layer is in situ generated on the surface of the zirconium alloy sample processed by ion implantation and thermal oxidation. There is an oxygen-rich diffusion layer between the substrate and the zirconium oxide ceramic layer. The thickness of the zirconium oxide layer is greater than the thickness of the Zr element injection layer. Its structure is as follows: Figure 1 As shown, from the surface to the inside, there are a zirconium oxide ceramic layer 1, an oxygen-rich diffusion layer 2, a zirconium element injection layer 3 and a zirconium alloy matrix 4.

[0055] Example 1

[0056] (1) Surface pretreatment

[0057] The zirconium alloy sample uses Zr-2.5Nb as the matrix, and there is no special size requirement for the sample;

[0058] The sample surface needs to be subjected to conventional grinding and polishing treatment, and after being polished with 200#, 500#, 1000#, and 2000# sandpaper, it is polished with a polishing disc and a polishing wheel, and the surface roughness (Ra) is controlled within the range of 1μm to 0.02μm. Subsequently, the titanium alloy sample is immersed in acetone, deionized water, and anhydrous ethanol for ultrasonic cleaning for 10 to 15 minutes, and the surface is air-dried.

[0059] (2) Surface zirconium ion implantation

[0060] Use a metal ion implanter to perform zirconium ion implantation processing, and select metal zirconium as the implantation cathode material; place the cleaned sample in the vacuum process chamber of the ion implanter and rotate it on a turntable, with the sample injection surface and the ion implantation tube forming an angle of 60 to 120 degrees;

[0061] Close the process chamber and evacuate the vacuum to 1.0×10 -3 ~2.0×10 -4 Pa; the ion implantation parameters are set as suppression voltage 0.9-1.1 kV, suppression current 0.1-2 mA, extraction voltage 45-50 kV, extraction current ≤5 mA, workpiece target current ≤4 mA, and implantation time 30-180 min;

[0062] After the vacuum degree reaches the standard, ion implantation is carried out; after the implantation is completed, the temperature in the process chamber drops to room temperature, air is filled in, the sample is taken out, and the zirconium ion implantation is completed.

[0063] (3) Preparation of zirconia ceramic layer

[0064] The sample after zirconium element injection is implanted into a crucible, and the crucible containing the sample is placed in a conventional heat treatment furnace chamber to perform thermal oxidation treatment under normal pressure and atmospheric conditions;

[0065] Set the heating parameters to a heating rate of 1 to 10°C / min, a holding temperature of 450 to 650°C, a holding time of 150 to 400 minutes, and keep the furnace temperature constant during the holding time;

[0066] After the heat preservation is completed, the sample is cooled to below 150°C in the furnace and then taken out, thus completing the thermal oxidation in-situ preparation of the zirconia ceramic layer.

[0067] Example 2

[0068] This embodiment provides a method for preparing a zirconium alloy material with an in-situ surface modified oxide ceramic layer. The operation steps are consistent with those in Example 1, and the parameters of each step are shown in Table 1.

[0069] Example 3

[0070] This embodiment provides a method for preparing a zirconium alloy material with an in-situ surface modified oxide ceramic layer. The operation steps are consistent with those in Example 1, and the parameters of each step are shown in Table 1.

[0071] Table 1 Example data

[0072]

[0073] Comparative Example 1

[0074] The unprocessed Zr-2.5Nb substrate is used as Comparative Example 1.

[0075] Comparative Example 2

[0076] This comparative example provides a method for preparing a zirconium alloy material with an in-situ surface modified oxide ceramic layer. In the pretreatment step, the surface roughness is adjusted to 1.5 μm, and the remaining steps are consistent with Example 1.

[0077] Comparative Example 3

[0078] This comparative example provides a method for preparing a zirconium alloy material with an in-situ surface modified oxide ceramic layer. In the pretreatment step, the surface roughness is adjusted to 0.015 μm, and the remaining steps are consistent with Example 1.

[0079] Comparative Example 4

[0080] This comparative example provides a method for preparing a zirconium alloy material with an in-situ surface modified oxide ceramic layer. In the preparation method, an ion implantation process is performed alone, and the remaining steps are consistent with those in Example 1.

[0081] Comparative Example 5

[0082] This comparative example provides a method for preparing a zirconium alloy material with an in-situ surface modified oxide ceramic layer. In the preparation method, a thermal oxidation process is performed alone, and the remaining steps are consistent with those in Example 1.

[0083] Comparative Example 6

[0084] This comparative example provides a method for preparing a zirconium alloy material with an in-situ surface modified oxide ceramic layer. During the surface zirconium ion implantation process, the target current of the workpiece is increased to 5 mA; the remaining steps are consistent with Example 1.

[0085] Comparative Example 7

[0086] This comparative example provides a method for preparing a zirconium alloy material with an in-situ modified oxide ceramic layer on the surface. During the thermal oxidation process, the insulation temperature rises to 680° C.; the remaining steps are consistent with those in Example 1.

[0087] Test Example 1 Sample properties and thickness

[0088] 1. Sample photos

[0089] The photos of the zirconium alloy substrate and the samples prepared by this method in Examples 1, 2, and 3 are shown in FIG. Figure 2 As shown, Figure I, Figure II, Figure III and Figure IV correspond to the zirconium alloy substrate (Comparative Example 1) and Examples 1, 2, and 3, respectively.

[0090] 2. Thickness of zirconia ceramic layer

[0091] The thickness of the zirconium oxide ceramic layer of the zirconium alloy substrate after direct thermal oxidation without Zr element injection and the samples prepared by this method in Examples 1, 2, and 3 are shown in the micrographs as follows: Figure 3 to Figure 6 shown; Figure 3 The zirconium oxide ceramic layer of the sample of Example 1, Figure 4 The zirconia ceramic layer of the sample of Example 2, Figure 5 The zirconium oxide ceramic layer of the sample of Example 3, Figure 6 This is the zirconia ceramic layer of the sample of Comparative Example 1 (substrate).

[0092] The thickness of each sample is shown in Table 2.

[0093] Table 2 Thickness of zirconia ceramic layer

[0094] sample Thickness(μm) Example 1 6.14 Example 2 6.30 Example 3 6.83 Comparative Example 1 6.09 Comparative Example 2 6.12 Comparative Example 3 6.72 Comparative Example 4 Injected alone, not oxidized Comparative Example 5 6.03 Comparative Example 6 6.10 Comparative Example 7 6.67

[0095] Test Example 2 Phase Analysis

[0096] The instrument has an operating voltage of 40 kV and a current of 100 mA. It uses Cu target Ka radiation, a scanning angle of 20° to 90°, and a scanning rate of 6° / min.

[0097] Data analysis was performed using JADE 6.0 software.

[0098] Phase purity and content of zirconium oxide ceramic layer: The XRD phase analysis results of the zirconium alloy substrate directly thermally oxidized without Zr element injection and the samples prepared by this method in Examples 1, 2, and 3 are as follows: Figure 7 As shown, Figure I is a Zr alloy substrate, Figure II is Example 1, Figure III is Example 2, and Figure IV is Example 3.

[0099] It can be seen from the XRD pattern that m-ZrO 2 The phase peak intensity of m-ZrO was significantly increased after ion implantation and thermal oxidation. 2 The peak intensity of the sample is significantly lower than that of the example sample, indicating that the zirconium oxide generated after ion implantation of Zr element and thermal oxidation has higher purity and content.

[0100] Test Example 3 Microhardness Test

[0101] According to GB / T 4340.1-2009 "Metallic Materials Vickers Hardness Test Part 1: Test Method", at the 100gf force level, the loading and holding time is set to 10s, 5 points are measured for each sample, and the average value is taken.

[0102] Compared with the titanium alloy substrate, the surface microhardness of the prepared zirconia ceramic layer sample is increased by 18-25%, and the microhardness is significantly improved. The surface microhardness performance test results are shown in Table 3.

[0103] Table 3 Test standards and Vickers hardness test results of Examples 1, 2, and 3 of the present invention

[0104]

[0105]

[0106] Combining the thickness data and hardness test results, it can be seen that the thickness of the zirconia ceramic layer on the surface of each sample is about 6μm, and the hardness is also improved to varying degrees. Compared with the embodiments, except for Comparative Example 4, where no zirconia ceramic layer is formed, the thickness of the zirconia ceramic layer formed by Comparative Examples 1, 2, 5, and 6 is not uniform, and the zirconia layer preferentially generated on the surface of the material is not dense enough, resulting in the inability to block the continuous diffusion of oxygen elements during the thermal oxidation process; and the hardness improvement of Comparative Examples 5 and 6 is not obvious.

[0107] The zirconia ceramic layers formed in Comparative Examples 3 and 7 are the same as those in the embodiment, and also have uniform thickness; however, the increase in thickness in Comparative Example 3 increases polishing difficulty and polishing cost, so the roughness is preferably set to 1μm-0.02μm in the present invention; Comparative Example 7 shows that the change in thermal oxidation process parameters has little effect on the thickness of the zirconia ceramic layer.

[0108] The present invention improves the concentration of Zr element within a certain depth range on the surface of the zirconium alloy on the basis of realizing metal-ceramic composite on the surface of the zirconium alloy. The zirconium oxide ceramic layer formed in the subsequent thermal oxidation process has higher purity and the thickness of the zirconium oxide layer is easy to control, which is suitable for application and promotion in the field of high technology.

[0109] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a zirconium alloy material with an in-situ surface modified oxide ceramic layer, characterized in that: The preparation method comprises the following steps: The zirconium alloy sample is subjected to grinding and polishing treatment, and then ion implantation is performed on the zirconium alloy sample under vacuum conditions using metal zirconium as an ion implantation source; After the ion implantation is completed, the zirconium alloy sample is subjected to thermal oxidation treatment in an air atmosphere to obtain a zirconium alloy material with an in-situ modified zirconium oxide ceramic layer.

2. The preparation method according to claim 1, characterized in that: The surface roughness of the zirconium alloy sample obtained after the grinding and polishing treatment is ≤1 μm; The grinding and polishing process also includes cleaning and drying operations.

3. The preparation method according to claim 2, characterized in that: The cleaning is ultrasonic cleaning, and the ultrasonic cleaning is performed using any one of acetone, deionized water or anhydrous ethanol, or two or more reagents; The drying method is air drying.

4. The preparation method according to claim 1, characterized in that: The parameters of the ion implantation are set as follows: suppression voltage 0.9-1.1 kV, suppression current 0.1-2 mA, extraction voltage 45-50 kV, extraction current ≤5 mA, workpiece target current ≤4 mA; The ion implantation time is 30 to 180 minutes.

5. The preparation method according to claim 1, characterized in that: The vacuum degree of the vacuum condition is 3.0×10 -3 ~6.0×10 -4 Pa; The injection surface of the zirconium alloy sample forms an angle of 60-120° with the ion injection tube; The rotation speed of the zirconium alloy sample during the ion implantation process is 5 to 10 r / min.

6. The preparation method according to claim 1, characterized in that: The heating rate of the thermal oxidation is 1 to 10°C / min; The thermal oxidation has a holding temperature of 450 to 650° C. and a holding time of 150 to 400 minutes.

7. The preparation method according to claim 1, characterized in that: The thermal oxidation is carried out under normal pressure.

8. A zirconium alloy material prepared by the preparation method according to any one of claims 1 to 7.

9. Use of the method according to any one of claims 1 to 7 or the zirconium alloy material according to claim 8 in the preparation of aerospace equipment, marine equipment or medical materials.

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