Wear-resistant and corrosion-resistant WC-Co-Cr coating

Abstract

The invention relates to the technical field of aviation, automobiles and energy, and discloses a wear-resistant and corrosion-resistant WC-Co-Cr coating which comprises the following components: WC [tungsten carbide], Co [cobalt] and Cr [chromium], and is prepared on a 0Cr13N i5Mo super martensitic stainless steel matrix through a high-speed oxygen [air] fuel [HVOF / HVAF] thermal spraying technology. The coating shows excellent wear resistance and corrosion resistance in artificial seawater and distilled water environments. According to the wear-resistant and corrosion-resistant WC-CoCr coating, the high-performance coating is successfully prepared on a 0Cr13Ni5Mo super martensitic stainless steel substrate by precisely regulating and controlling the proportion of WC, Co and Cr and combining an HVOF / HVAF thermal spraying technology with different parameters, the coating shows excellent wear resistance and corrosion resistance in distilled water and artificial seawater environments, and the wear resistance and corrosion resistance of the coating are greatly improved. And the service life of the assembly in an extreme operation environment is effectively prolonged.

Description

Technical Field

[0001] The invention relates to the fields of aviation, automobile and energy technology, in particular to a wear-resistant and corrosion-resistant WC-Co-Cr coating. Background Art

[0002] In the modern industrial field, especially in key industries such as aviation, automobile and energy, components often face extreme operating environments, such as aircraft landing gear and oil pipelines, and are easily damaged under harsh conditions of corrosion and wear. Therefore, their surfaces are required to have excellent mechanical properties and durability.

[0003] In some existing methods, researchers have only focused on conducting extensive research under standard atmospheric pressure. However, most of these studies focus on the ideal environment of the laboratory. These studies often ignore the more complex environmental conditions that the coating may encounter in practical applications, especially in seawater and distilled water environments. There are relatively few studies on the corrosion and wear behavior of WC-Co-Cr coatings. Seawater not only intensifies chemical corrosion, but also introduces the lubrication and cooling effects of liquid media. These factors may significantly affect the wear performance and durability of the coating, so a wear-resistant and corrosion-resistant WC-Co-Cr coating is proposed. Summary of the invention

[0004] 1. Technical issues to be solved

[0005] In view of the deficiencies in the prior art, the present invention provides a wear-resistant and corrosion-resistant WC-Co-Cr coating, which has the advantages of excellent wear resistance and corrosion resistance in artificial seawater and distilled water environments, and solves the problems of insufficient research on the corrosion and wear behavior of existing WC-Co-Cr coatings under complex environmental conditions [especially seawater and distilled water environments], as well as the problem of decreased mechanical properties and durability that may be encountered in practical applications.

[0006] (II) Technical solution

[0007] In order to achieve the above-mentioned purpose of exhibiting excellent wear resistance and corrosion resistance in artificial seawater and distilled water environments, the present invention provides the following technical solution: a wear-resistant and corrosion-resistant WC-Co-Cr coating, which is composed of the following formula: WC (tungsten carbide), Co (cobalt), Cr (chromium), and is prepared on a 0Cr13Ni5Mo super martensitic stainless steel substrate by high-speed oxygen (air) fuel (HVOF / HVAF) thermal spraying technology. The coating exhibits excellent wear resistance and corrosion resistance in artificial seawater and distilled water environments.

[0008] As a preferred technical solution of the present invention, the coating is prepared by using three different HVOF / HVAF process technologies, and the prepared coatings are marked as AC, BC and CC respectively.

[0009] As a preferred technical solution of the present invention, the friction test of the coating is carried out on a standard reciprocating friction tester, the test solutions are distilled water and artificial seawater (pH 8.2), and a Rockwell HRC-3 natural diamond indenter is used to carry out a reciprocating friction test on the surface of the test sample. Different loads are applied by placing a calibrated weight above the indenter to determine the wear mechanism under different load levels.

[0010] As a preferred technical solution of the present invention, the load levels include 5N, 8.9N, 13.8N and 23.6N, the reciprocating frequency is set to 2Hz, the furnace temperature is maintained at 36°C, and each load test lasts for 2 hours.

[0011] As a preferred technical solution of the present invention, during the preparation of the coating, the original substrate is cut into square samples with a size of 15 mm×6.6 mm×6.6 mm, and the surface of the sample is ground and polished to obtain a smooth surface without visible scratches.

[0012] (III) Beneficial effects

[0013] Compared with the prior art, the present invention provides a wear-resistant and corrosion-resistant WC-Co-Cr coating, which has the following beneficial effects:

[0014] This wear-resistant and corrosion-resistant WC-CoCr coating was successfully prepared on a 0Cr13Ni5Mo super martensitic stainless steel substrate by precisely controlling the ratio of WC, Co, and Cr and combining HVOF / HVAF thermal spraying technology with different parameters. The coating exhibited excellent wear resistance and corrosion resistance in both distilled water and artificial seawater environments, effectively extending the service life of the components in extreme operating environments. In addition, by optimizing the preparation process, the cross-sectional morphology and microstructure of the coating were significantly improved, further enhancing its mechanical properties and durability. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of process parameters of the present invention. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0018] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0019] Example 1

[0020] See also Figure 1 This embodiment provides a wear-resistant and corrosion-resistant WC-Co-Cr coating, whose formula composition is: WC (tungsten carbide) accounts for 60% of the total mass of the coating, Co (cobalt) accounts for 30% of the total mass of the coating, and Cr (chromium) accounts for 10% of the total mass of the coating. The coating is prepared on a 0Cr13Ni i5Mo super martensitic stainless steel substrate by HVOF technology.

[0021] During the preparation process, the original substrate was first cut into square specimens with a size of 15 mm × 6.6 mm × 6.6 mm using an electric spark wire cutting machine. Then, the sample surface was continuously ground using silicon carbide sandpaper with a grit range of 180 to 2000 until a smooth surface without visible scratches was obtained. Subsequently, the sample was polished using 2.5 μm diamond paste.

[0022] The friction test was carried out on a standard reciprocating friction tester. The test solutions were distilled water and artificial seawater (pH 8.2). A Rockwell HRC-3 natural diamond indenter was used to carry out a reciprocating friction test on the test sample surface. The load level was set to 5N, the reciprocating frequency was set to 2Hz, the furnace temperature was maintained at 36°C, and the experiment lasted for 2 hours. After the experiment, a scanning electron microscope (SEM) was used to examine the microstructure after wear, and the change of the friction coefficient over time was recorded.

[0023] In this embodiment, 0Cr13N i5Mo super martensitic stainless steel is mainly selected as the target material, and the WC-Co-Cr coating is prepared by HVOF thermal spraying technology. The specific process parameters are as follows: oxygen flow rate is 300L / h, fuel flow rate is 40L / h, spraying distance is 200mm, and spraying speed is 800mm / s. The prepared coating sample is marked as AC, and the cross-sectional morphology is observed and analyzed. Subsequently, a friction test was carried out on a standard reciprocating friction tester. The test solution was distilled water with a pH value of 8.2 and a load level of 5N. After the experiment, a scanning electron microscope was used to examine the microstructure after wear, and the change of the friction coefficient over time was recorded. The results showed that the AC coating exhibited good wear resistance and corrosion resistance in a distilled water environment.

[0024] Example 2

[0025] The present embodiment provides a wear-resistant and corrosion-resistant WC-Co-Cr coating, whose formula composition is: WC (tungsten carbide) accounts for 55% of the total mass of the coating, Co (cobalt) accounts for 35% of the total mass of the coating, and Cr (chromium) accounts for 10% of the total mass of the coating. The coating is prepared on a 0Cr13Ni i5Mo super martensitic stainless steel substrate by HVAF technology. The coating is prepared by three different HVOF / HVAF process technologies, and the process parameters are as follows: Figure 1 As shown, the prepared coatings are marked as AC, BC and CC respectively.

[0026] The preparation process is similar to that of Example 1, except for the coating formulation and preparation technology. In addition, the load level of the friction test is set to 8.9N, and the other conditions are the same as those of Example 1.

[0027] In this example, another HVOF thermal spraying technology was used to prepare the WC-Co-Cr coating. The specific process parameters were optimized and adjusted according to actual needs. The prepared coating sample was marked as CC, and the cross-sectional morphology was observed and analyzed. In the friction test, distilled water and artificial seawater were used as test solutions at the same time, and the load levels were 8.9N and 23.6N, respectively. The experimental results show that the CC coating exhibits excellent wear resistance and corrosion resistance in both environments, and can maintain stable performance under different load levels. Example 3

[0028] This embodiment provides a wear-resistant and corrosion-resistant WC-Co-Cr coating, whose formula composition is: WC (tungsten carbide) accounts for 65% of the total mass of the coating, Co (cobalt) accounts for 25% of the total mass of the coating, and Cr (chromium) accounts for 10% of the total mass of the coating. The coating is prepared on a 0Cr13Ni i5Mo super martensitic stainless steel substrate by another HVOF technology (different from the technology in Example 1).

[0029] The preparation process is similar to that of Example 1, except for the coating formulation and preparation technology. In addition, the load levels of the friction test are set to 13.8 N and 23.6 N, and the other conditions are the same as those of Example 1.

[0030] In this embodiment, 0Cr13Ni5Mo super martensitic stainless steel is also selected as the target material, but the WC-Co-Cr coating is prepared by HVAF thermal spraying technology. The specific process parameters are as follows: air flow rate is 400L / h, fuel flow rate is 50L / h, spraying distance is 250mm, spraying speed is 1000mm / s, and the prepared coating sample is marked as BC, and corresponding tests and analyses are performed. In the friction test, the test solution is artificial seawater with a pH value of 8.2, and the load level is 13.8N. The experimental results show that the BC coating has excellent wear resistance and corrosion resistance in the artificial seawater environment.

[0031] The beneficial effects of the above embodiment are:

[0032] By precisely controlling the ratio of WC, Co, and Cr and combining HVOF / HVAF thermal spraying technology with different parameters, a high-performance coating was successfully prepared on a 0Cr13Ni5Mo super martensitic stainless steel substrate. The coating exhibited excellent wear resistance and corrosion resistance in both distilled water and artificial seawater environments, effectively extending the service life of the components in extreme operating environments. In addition, by optimizing the preparation process, the cross-sectional morphology and microstructure of the coating were significantly improved, further enhancing its mechanical properties and durability.

[0033] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A wear-resistant and corrosion-resistant WC-Co-Cr coating, characterized in that: The coating is composed of the following formula: WC [tungsten carbide], Co [cobalt], Cr [chromium], and is prepared on a 0Cr13Ni5Mo super martensitic stainless steel substrate by high-speed oxygen [air] fuel [HVOF / HVAF] thermal spraying technology. The coating exhibits excellent wear resistance and corrosion resistance in artificial seawater and distilled water environments.

2. The wear-resistant and corrosion-resistant WC-Co-Cr coating according to claim 1, characterized in that: The coatings are prepared using three different HVOF / HVAF process technologies, and the prepared coatings are marked as AC, BC and CC, respectively.

3. The wear-resistant and corrosion-resistant WC-Co-Cr coating according to claim 2, characterized in that: The friction test of the coating was carried out on a standard reciprocating friction tester. The test solutions were distilled water and artificial seawater [pH 8.2]. A Rockwell HRC-3 natural diamond indenter was used to carry out a reciprocating friction test on the test sample surface. Different loads were applied by placing a calibrated weight above the indenter to determine the wear mechanism under different load levels.

4. The wear-resistant and corrosion-resistant WC-Co-Cr coating according to claim 3, characterized in that: The load levels included 5N, 8.9N, 13.8N and 23.6N, the reciprocating frequency was set to 2 Hz, the furnace temperature was maintained at 36°C, and each load test lasted for 2 hours.

5. The wear-resistant and corrosion-resistant WC-Co-Cr coating according to claim 4, characterized in that: During the preparation of the coating, the original substrate was cut into square specimens with a size of 15 mm×6.6 mm×6.6 mm, and the surface of the specimen was ground and polished to obtain a smooth surface without visible scratches.

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