Softening agent for platinum plating and preparation method of high-temperature alloy low-stress platinum plating layer
By combining softener with basic plating solution and performing multiple cleaning processes, the problems of high plating stress and oxide inclusions were solved, achieving stable preparation of low-stress plating layers on high-temperature alloys and improving the adhesion and density of the plating layer.
Patent Information
- Application Number
- CN202511929397.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-19
- Publication Date
- 2026-03-03
AI Technical Summary
In existing platinum plating processes, acidic plating layers have high stress and are prone to cracking when the thickness exceeds 2μm. The stress of alkaline plating layers also increases significantly with increasing thickness. Furthermore, high-temperature alloys are prone to oxide inclusions and impurity element contamination during plating, resulting in poor coating adhesion.
A method for preparing a low-stress platinum plating layer using softeners includes sandblasting, ultrasonic cleaning, inclusion removal, and activation treatment. Quaternary ammonium salt softeners such as dodecyltrimethylammonium chloride are mixed with the basic plating solution, and multiple ultrasonic cleanings are performed after electroplating to obtain a low-stress thick platinum plating layer.
It effectively reduces coating stress, avoids cracking and oxide inclusions, improves coating adhesion, and ensures a dense and defect-free coating. It is suitable for preparing low-stress platinum coatings on high-temperature alloy surfaces.
Smart Images
Figure CN121593141A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of platinum plating technology, and in particular to a softener for platinum plating and a method for preparing a high-temperature alloy low-stress platinum plating layer thereof. Background Technology
[0002] Aero-engine blades are critical components of engines, made of various high-strength, high-temperature alloys. They operate in extremely harsh environments, including high pressure ratios, high gas temperatures, high loads, and large flow rates. High-performance compressor blades are thin and have curved, twisted, and swept configurations. During high-speed rotation, they must withstand centrifugal forces 20,000 times their own weight for extended periods. The airflow environment temperature for turbine blades reaches 2000-2200K, far exceeding the melting point of their metallic materials. Under such severe conditions, the blades are required to operate reliably for extended periods at speeds of 10,000-20,000 rpm. To ensure the long-term stable operation of high-temperature blades in the high-temperature combustion chamber, high-temperature protective coatings such as anti-oxidation coatings or thermal barrier coatings are needed to extend their service life. Among various modified aluminum oxide coatings, Pt-modified aluminum oxide coatings (PtAl coatings) offer the best overall performance in terms of oxidation resistance, corrosion resistance, and mechanical properties, and are therefore widely used on high-temperature blades. This coating can significantly improve the oxidation / thermal corrosion resistance of high-temperature blades, potentially increasing their service life by three to four times.
[0003] Platinum plating processes can be categorized into alkaline platinum plating, near-neutral platinum plating, and acidic platinum plating processes based on the pH value of the plating solution. According to the main salt, platinum plating processes can also be broadly classified into "P-salt platinum plating," "Q-salt platinum plating," "DNS platinum plating," and "chloroplatinate platinum plating." These platinum plating processes all have some problems in practical use. The main issues are: acidic platinum plating solutions have fast plating speeds and low operating temperatures (around 60℃), producing bright and fine coatings, but with high coating stress, cracking and peeling are very likely once the coating thickness exceeds 2μm; alkaline platinum plating solutions have good dispersion capabilities, resulting in relatively lower coating stress compared to acidic platinum plating, but the coating stress increases significantly with increasing thickness; alkaline platinum plating solutions have low current efficiency, high plating solution temperatures, and release a large amount of pungent ammonia odor into the environment during use.
[0004] In the aforementioned prior art, acidic plating has high stress, and it is very easy to crack and peel when the plating thickness exceeds 2μm. Alkaline plating has relatively lower stress than acidic plating, but the plating stress will also increase significantly with the increase of plating thickness, especially when plating plating thicker plating than 5μm. Due to the high stress of the plating, it is very easy to peel and crack. At the same time, during the plating process of high-temperature alloys, the substrate and the plating layer are prone to inclusion defects of oxides and inorganic substances, as well as poor coating strength and contamination by impurities such as sulfur, chlorine and phosphorus. Therefore, there is an urgent need for a low-stress plating softener and a method for preparing a low-stress plating layer for high-temperature alloys. Summary of the Invention
[0005] The purpose of this invention is to provide a platinum plating softener and a method for preparing a low-stress platinum plating layer on a high-temperature alloy. This addresses the problems of existing technologies where acidic plating exhibits high stress, leading to cracking and peeling when the plating thickness exceeds 2 μm; alkaline plating has relatively lower stress compared to acidic plating, but the stress increases significantly with thickness, especially when plating thicker platinum (greater than 5 μm), where high stress makes peeling and cracking very likely; and the high stress on high-temperature alloys during plating, which can result in inclusions of oxides and inorganic substances, poor adhesion, and contamination by impurities such as sulfur, chlorine, and phosphorus. Therefore, there is an urgent need for a low-stress plating softener and a method for preparing a low-stress platinum plating layer on a high-temperature alloy.
[0006] To achieve the above objectives, the present invention employs a method for preparing a low-stress platinum plating layer using a high-temperature alloy softener for plating, comprising the following steps:
[0007] The high-temperature alloy specimens were sequentially subjected to sandblasting, ultrasonic cleaning, inclusion removal, and activation to obtain the treated high-temperature alloy specimens.
[0008] A softener is added to the basic plating solution to obtain a low-stress plating solution;
[0009] The treated high-temperature alloy specimen was placed in a low-stress platinum plating solution and electroplated by passing an electric current to obtain a high-temperature alloy platinum-plated specimen.
[0010] High-temperature alloy platinum-plated specimens were subjected to multi-stage ultrasonic cleaning to remove impurities, followed by drying to obtain a low-stress thick platinum-plated layer.
[0011] This invention also provides a softener for platinum plating, wherein in the step of adding the softener to a basic platinum plating solution to obtain a low-stress platinum plating solution:
[0012] The basic platinum plating solution is one of P-salt platinum plating solution, Q-salt platinum plating solution, or DNS platinum plating solution.
[0013] The softener is composed of one or a mixture of several of the following: dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, and octadecyltrimethylammonium chloride.
[0014] The P-salt platinum plating solution consists of: 2-15 g / L dinitrosodiammineplatinum (calculated as platinum), 10-100 g / L ammonium nitrate, and 5-20 g / L sodium nitrite, wherein ammonia water is used to adjust the pH to 8-12.
[0015] The Q-salt platinum plating solution consists of 1~8 g / L of tetraammonium hydrogen phosphate platinum and 10~80 g / L of triammonium phosphate, wherein the pH is adjusted to 8~12 with ammonia water.
[0016] DNS platinum plating solution consists of 2~8 g / L of platinum-calcium sulfuric acid dinitrosoplatinic acid and 10~100 ml / L of sulfuric acid.
[0017] The concentration of one or more of the following in the platinum plating solution is 0.01–0.5 g / L: dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, and octadecyltrimethylammonium chloride.
[0018] Among the steps, the high-temperature alloy test piece is subjected to sandblasting, ultrasonic cleaning, inclusion removal, and activation in sequence to obtain the treated high-temperature alloy test piece:
[0019] High-temperature alloy substrates are sandblasted using white corundum as the abrasive material, with a mesh size of 80-200 mesh, a pressure of 1-4 kg, and a time of 1-5 min.
[0020] Ultrasonic cleaning is performed on the sandblasted substrate. Sodium hydroxide: 5~20g / L, sodium carbonate: 5~40g / L, trisodium phosphate: 5~40g / L, temperature: 50~70℃, time: 3~15min, ultrasonic frequency: 40~80kHz.
[0021] The ultrasonically cleaned substrate is subjected to inclusion removal treatment. The inclusion removal solution is composed of one or two of ammonium bifluoride or sodium dihydrogen fluoride, with a content of 20~80g / L, a temperature of 20~35℃, and a time of 2~5min.
[0022] The substrate after inclusion removal is activated using a hydrochloric acid solution with a concentration of 10-30%, at room temperature for 1-5 minutes.
[0023] In the step of placing the treated high-temperature alloy specimen in a low-stress platinum plating solution and electroplating it to obtain a high-temperature alloy platinum-plated specimen:
[0024] The activated substrate is subjected to low-stress plating; the plating temperature is 60~98℃, the current density is 1~5A / dm2, and the coating thickness is 3~5 micrometers.
[0025] The present invention discloses a softener for platinum plating and a method for preparing a low-stress platinum plating layer on a high-temperature alloy. The method involves sequentially subjecting a high-temperature alloy sample to sandblasting roughening, ultrasonic cleaning, inclusion removal, and activation treatment to obtain a treated high-temperature alloy sample; adding the softener to a basic platinum plating solution to obtain a low-stress platinum plating solution; placing the treated high-temperature alloy sample in the low-stress platinum plating solution and electroplating; and then sequentially subjecting the platinum-plated sample to multiple ultrasonic cleaning processes to remove impurities, thereby obtaining a low-stress thick platinum plating layer.
[0026] Therefore, sandblasting is first performed to remove the oxide and machining layers from the surface of the high-temperature alloy, roughening the workpiece surface and effectively improving the adhesion of the coating and reducing the stress of the coating. Then, ultrasonic cleaning is performed to remove sand particles and other contaminants from the surface of the high-temperature alloy. Next, inclusion removal is performed to remove sand particles, inorganic matter, and other contaminants embedded in the substrate, effectively avoiding defects such as voids and oxide inclusions between the coating and the substrate. After activation, the oxide layer on the workpiece surface is removed. Finally, low-stress platinum plating is performed to obtain a high-purity, dense platinum layer free of oxide and inorganic inclusions and with low stress. This effectively solves the core problems of existing technologies, such as high stress in thick platinum coatings, easy peeling and cracking, easy inclusions between the coating and the substrate, and easy contamination by impurity elements, achieving stable preparation of low-stress platinum layers for high-temperature alloys. Attached Figure Description
[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0028] Figure 1 This is a flowchart of the steps in the preparation method of the high-temperature alloy low-stress platinum plating layer of the softener for platinum plating according to the present invention.
[0029] Figure 2 This is a flowchart of steps S100 of the present invention.
[0030] Figure 3 This is a flowchart of steps S200 of the present invention.
[0031] Figure 4 This is a flowchart of steps S300 of the present invention.
[0032] Figure 5 This is a flowchart of steps S400 of the present invention.
[0033] Figure 6 Table 1 shows the results obtained from Embodiment 1 of the present invention.
[0034] Figure 7 Table 2 shows the results obtained from Embodiment 1 of the present invention.
[0035] Figure 8 Table 3 shows the results obtained from Embodiment 2 of the present invention.
[0036] Figure 9 Table 4 shows the results obtained from Embodiment 2 of the present invention.
[0037] Figure 10Table 5 shows the results obtained from Embodiment 3 of the present invention.
[0038] Figure 11 Table 6 shows the results obtained from Embodiment 3 of the present invention.
[0039] Figure 12 Table 7 shows the results obtained in Embodiment 4 of the present invention.
[0040] Figure 13 Table 8 shows the results obtained from Embodiment 4 of the present invention. Detailed Implementation
[0041] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application.
[0042] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.
[0043] It should be understood that although the terms first, second, third, etc., may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."
[0044] Please see Figures 1-5 This invention provides a method for preparing a low-stress platinum plating layer of a high-temperature alloy softener for plating, comprising the following steps:
[0045] S100: The high-temperature alloy specimen is subjected to sandblasting, ultrasonic cleaning, inclusion removal and activation in sequence to obtain the treated high-temperature alloy specimen.
[0046] Specifically, it includes:
[0047] S101: Place the high-temperature alloy test piece in a sandblasting machine. Select white corundum as the abrasive material. The mesh size is 80~200. The pressure is 1~4Kg. The time is 1~5min. Remove the oxide layer and processing layer on the surface of the high-temperature alloy to make the surface more uniform.
[0048] S102: Ultrasonic cleaning of the sandblasted substrate, sodium hydroxide: 5~20g / L, sodium carbonate: 5~40g / L, trisodium phosphate: 5~40g / L, temperature: 50~70℃, time: 3~15min, ultrasonic frequency: 40~80kHz.
[0049] S103: Perform inclusion removal treatment on the ultrasonically cleaned substrate. The inclusion removal solution is composed of one or two of ammonium bifluoride or sodium dihydrogen fluoride, with a content of 20~80g / L, a temperature of 20~35℃, and a time of 2~5min.
[0050] S104: Activate the substrate after removing inclusions using a hydrochloric acid solution with a concentration of 10-30%, at room temperature for 1-5 minutes.
[0051] S200: Softener is added to the basic plating solution to obtain a low-stress plating solution;
[0052] Specifically, it includes:
[0053] S201: Add the softener to the basic platinum plating solution at a concentration of 0.01~0.5g / L and stir until homogeneous;
[0054] S202: Maintain the plating solution temperature at 50~95℃ and keep it at that temperature for 0.5~2 hours.
[0055] S300: The treated high-temperature alloy specimen is placed in a low-stress platinum plating solution and electroplated by passing an electric current to obtain a high-temperature alloy platinum-plated specimen.
[0056] Specifically, it includes:
[0057] S301: Inject the low-stress platinum plating solution into the electroplating tank, turn on the plating solution circulation pump, and let the low-stress platinum plating solution circulate and filter through a 5μm filter element to maintain the plating solution temperature at 60~95℃.
[0058] S302: The treated high-temperature alloy sample is placed in the electroplating tank as a cathode, charged, and first impacted with a current density of 1.5 to 2 times the normal current for 1 to 5 minutes, then adjusted to the normal current density of 1 to 5 A / dm. 2 The thickness of the platinum layer is controlled between 2 and 7 micrometers.
[0059] S400: High-temperature alloy platinum-plated specimens are subjected to multi-stage ultrasonic cleaning to remove impurities, followed by drying to obtain a low-stress thick platinum-plated layer.
[0060] Specifically including
[0061] S401: Place the initial platinum plating sample in deionized water and perform ultrasonic cleaning for 3-5 minutes at a frequency of 40-80 kHz.
[0062] S402: Place the high-temperature alloy platinum-plated sample in hot deionized water at 50~80℃ and perform ultrasonic cleaning for 10~20 minutes at an ultrasonic frequency of 40~80kHz.
[0063] S403: Blow away excess moisture from the high-temperature alloy platinum-plated test piece with purified compressed air;
[0064] S404: Place the high-temperature alloy platinum-plated test piece in an oven and bake at 60~120℃ for 20~60 minutes.
[0065] The dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, and octadecyltrimethylammonium chloride of this application are quaternary ammonium salts. One end of their molecules carries a positive charge and can be adsorbed on the electrode surface, while the other end has a carbon chain structure. This structure can cause the electrocrystallization of platinum ions in a certain way, thereby reducing the stress of the coating and eliminating peeling and cracking after the coating is thickened.
[0066] Corresponding to the aforementioned embodiments of the method for preparing a low-stress platinum plating layer of a high-temperature alloy using a softener for platinum plating, this application also provides embodiments of a softener for platinum plating.
[0067] Please see Figure 6 and 7 Example 1:
[0068] Content of plating softener in the plating bath by weight concentration:
[0069] Dodecyltrimethylammonium chloride: 0.1 g / L.
[0070] Basic platinum plating solution
[0071] Dinitrosodiammineplatinum (P salt): 10 g / L (calculated as platinum)
[0072] Ammonium sulfate: 50g / L
[0073] Sulfuric acid: 50 ml / L.
[0074] Process parameters: current density 1A / dm², temperature 60℃, anode to cathode area ratio greater than 2:1, electroplating time 60min. A nickel-plated sample measuring 50mm in length and 50mm in width was selected for plating, and the plating layer was inspected.
[0075] Basic platinum plating solution: The entire sample exhibits an extremely bright plating layer, but cracks and localized peeling at the edges are present. The plating thickness after 60 minutes of deposition is approximately 5.6 μm. Specific test data are shown in Table 1.
[0076] Platinum plating solution with added softener: The entire sample exhibits a uniform, fine, soft, and bright plating layer with good adhesion, no cracks, and no peeling. The plating thickness after 60 minutes of deposition is approximately 5.5 μm. Specific test data are shown in Table 2.
[0077] Table 1 Results obtained from platinum plating solutions with added softener Appearance Coating thickness (μm) Sample 1 The specimen exhibits a uniform, smooth, and soft gloss; the fracture surface after bending is flat without peeling or cracking. 5.41 Sample 2 The specimen exhibits a uniform, smooth, and soft gloss; the fracture surface after bending is flat without peeling or cracking. 5.42 Sample 3 The specimen exhibits a uniform, smooth, and soft gloss; the fracture surface after bending is flat without peeling or cracking. 5.76
[0078] Table 2. Properties of coatings obtained under conventional platinum plating bath conditions at medium temperature. Appearance Coating thickness (μm) Sample 1 The coating is extremely glossy, but it has cracks and peeling at the edges. 5.62 Sample 2 The coating is extremely glossy, but it has cracks and peeling at the edges. 5.45 Sample 3 The coating is extremely glossy, but it has cracks and peeling at the edges. 5.71
[0079] Please see Figure 8 and 9 Example 2
[0080] Content of plating softener in the plating bath by weight concentration:
[0081] Tetradecyltrimethylammonium chloride: 0.05 g / L.
[0082] Basic platinum plating solution
[0083] Dinitrosodiammineplatinum (P salt): 10 g / L (calculated as platinum)
[0084] Ammonium nitrate: 50g / L
[0085] Sodium nitrite: 50ml / L
[0086] Ammonia solution: 20ml / L.
[0087] Process parameters: current density 2A / dm², temperature 90℃, anode to cathode area ratio greater than 2:1, electroplating time 60min. A nickel-plated sample measuring 50mm in length and 50mm in width was selected for plating, and the plating layer was inspected.
[0088] Basic platinum plating solution: The entire sample exhibits a grayish-white plating layer without cracks or peeling. Bending the sample revealed slight chipping at the fracture surface. The plating thickness after 60 minutes of deposition was approximately 4.8 μm. Specific test data are shown in Table 3.
[0089] Platinum plating solution with added softener: The entire sample exhibits a uniform, fine, soft, and bright white coating with good adhesion, no cracks, and no peeling. When the sample is bent, the fracture surface is smooth, without peeling or cracking. The coating thickness deposited over 60 minutes is approximately 4.3 μm. Specific test data are shown in Table 4.
[0090] Table 3 Results obtained from platinum plating solutions with added softener Appearance Coating thickness (μm) Sample 1 The specimen exhibits a uniform, smooth, and bright white appearance; the fracture surface after bending is flat without peeling or cracking. 4.31 Sample 2 The specimen exhibits a uniform, smooth, and bright white appearance; the fracture surface after bending is flat without peeling or cracking. 4.16 Sample 3 The specimen exhibits a uniform, smooth, and bright white appearance; the fracture surface after bending is flat without peeling or cracking. 4.69
[0091] Table 4. Properties of coatings obtained under conventional platinum plating bath conditions at medium temperature. Appearance Coating thickness (μm) Sample 1 The coating is grayish-white, and there are cracks at the fracture point of the bent test piece. 4.67 Sample 2 The coating is grayish-white, and there is peeling at the fracture point of the bent test piece. 4.87 Sample 3 The coating is grayish-white, and there are cracks at the fracture point of the bent test piece. 4.98
[0092] Please see Figure 10 and 11 Example 3
[0093] Content of plating softener in the plating bath by weight concentration:
[0094] Hexadecyltrimethylammonium chloride: 0.05 g / L
[0095] Octadecyltrimethylammonium chloride: 0.05 g / L.
[0096] Basic platinum plating solution
[0097] Dinitrosolitic acid sulfate (DNS platinum salt): 8 g / L (based on platinum)
[0098] Sulfuric acid: 50 ml / L.
[0099] Process parameters: current density 1A / dm², temperature 60℃, anode to cathode area ratio greater than 2:1, electroplating time 60min. A nickel-plated sample measuring 50mm in length and 50mm in width was selected for plating, and the plating layer was inspected.
[0100] Basic platinum plating solution: The entire sample exhibits a bright white plating layer with cracks and localized peeling. The plating thickness after 60 minutes of deposition is approximately 6.7 μm. Specific test data are shown in Table 5.
[0101] Platinum plating solution with added softener: The entire sample exhibits a uniform, fine, soft, and bright white coating with good adhesion, no cracks, and no peeling. When the sample is bent, the fracture surface is smooth, without peeling or cracking. The coating thickness deposited over 60 minutes is approximately 6.1 μm. Specific test data are shown in Table 6.
[0102] Table 5 Results obtained from platinum plating solutions with added softener Appearance Coating thickness (μm) Sample 1 The specimen exhibits a uniform, smooth, and bright white appearance; the fracture surface after bending is flat without peeling or cracking. 6.14 Sample 2 The specimen exhibits a uniform, smooth, and bright white appearance; the fracture surface after bending is flat without peeling or cracking. 6.26 Sample 3 The specimen exhibits a uniform, smooth, and bright white appearance; the fracture surface after bending is flat without peeling or cracking. 5.93
[0103] Table 6. Properties of coatings obtained under conventional platinum plating bath conditions at medium temperature. Appearance Coating thickness (μm) Sample 1 The coating is uniform, fine, and bright white, but there are some cracks and peeling in some areas. 6.74 Sample 2 The coating is uniform, fine, and bright white, but there are some cracks and peeling in some areas. 6.46 Sample 3 The coating is uniform, fine, and bright white, but there are some cracks and peeling in some areas. 6.97
[0104] Please see Figure 12 and 13 Example 4
[0105] Content of plating softener in the plating bath by weight concentration:
[0106] Dodecyltrimethylammonium chloride: 0.01 g / L
[0107] Octadecyltrimethylammonium chloride: 0.03 g / L.
[0108] Basic platinum plating solution
[0109] Tetraammineplatinum hydrogen phosphate (Q salt): 5 g / L (based on platinum)
[0110] Triammonium phosphate: 50g / L
[0111] Ammonia water: 20ml / L
[0112] Ammonia solution: 20ml / L.
[0113] Process parameters: current density 1A / dm², temperature 95℃, anode to cathode area ratio greater than 2:1, electroplating time 90min. A nickel-plated sample measuring 50mm in length and 50mm in width was selected for plating, and the plating layer was inspected.
[0114] Basic platinum plating solution: The entire sample exhibits a uniform, bright white coating without cracks or peeling. Bending the sample revealed slight chipping at the fracture surface. The coating thickness after 90 minutes of deposition was approximately 4.2 μm. Specific test data are shown in Table 7.
[0115] Platinum plating solution with added softener: The entire sample exhibits a uniform, fine, soft, and bright white coating with good adhesion, no cracks, and no peeling. When the sample is bent, the fracture surface is smooth, without peeling or cracking. The coating thickness deposited after 90 minutes is approximately 4.4 μm. Specific test data are shown in Table 8.
[0116] Table 7 Results obtained from platinum plating solutions with added softener Appearance Coating thickness (μm) Sample 1 The specimen exhibits a uniform, smooth, and bright white appearance; the fracture surface after bending is flat without peeling or cracking. 4.34 Sample 2 The specimen exhibits a uniform, smooth, and bright white appearance; the fracture surface after bending is flat without peeling or cracking. 4.62 Sample 3 The specimen exhibits a uniform, smooth, and bright white appearance; the fracture surface after bending is flat without peeling or cracking. 3.92
[0117] Table 8. Properties of coatings obtained under conventional platinum plating bath conditions at medium temperature. Appearance Coating thickness (μm) Sample 1 The coating is uniform and bright white, and there is slight chipping at the fracture point of the bent test piece. 4.42 Sample 2 The coating is uniform and bright white, but there is peeling at the fracture point of the bent test piece. 3.96 Sample 3 The coating is uniform and bright white, and there is slight chipping at the fracture point of the bent test piece. 4.06
[0118] After the coating is completed: use the following methods for testing:
[0119] 1. Appearance inspection: The appearance should be inspected visually under natural diffused light or white projected light without reflection. The test piece should be placed 1.2 to 1.5 meters away from the object under 40W fluorescent light, and the eyes should be 35±5cm away from the part. The overall appearance of the test piece should be uniform, the coating should be fine, uniform and continuous, without cracks, peeling, blackening or roughness.
[0120] 2. Coating adhesion test: Repeatedly bend the test piece until it breaks, and observe the fracture surface. The coating should not peel, crack, or chip.
[0121] 3. Coating thickness measurement: The thickness is measured using an X-ray diffractometer. A fluorescent film thickness meter is placed upright in the center of the sample, and the coating thickness is measured after 1 hour of coating application.
[0122] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein.
[0123] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope.
Claims
1. A method for preparing a low-stress platinum plating layer using a softener high-temperature alloy for plating, characterized in that, Includes the following steps: The high-temperature alloy specimens were sequentially subjected to sandblasting, ultrasonic cleaning, inclusion removal, and activation to obtain the treated high-temperature alloy specimens. A softener is added to the basic plating solution to obtain a low-stress plating solution; The treated high-temperature alloy specimen was placed in a low-stress platinum plating solution and electroplated by passing an electric current to obtain a high-temperature alloy platinum-plated specimen. High-temperature alloy platinum-plated specimens were subjected to multi-stage ultrasonic cleaning to remove impurities, followed by drying to obtain a low-stress thick platinum-plated layer.
2. A softener for platinum plating, comprising the method for preparing a high-temperature alloy low-stress platinum plating layer using the softener for platinum plating as described in claim 1, characterized in that, In the step of adding a softener to a basic platinum plating solution to obtain a low-stress platinum plating solution: The basic platinum plating solution is one of P-salt platinum plating solution, Q-salt platinum plating solution, or DNS platinum plating solution. The softener is composed of one or a mixture of several of the following: dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, and octadecyltrimethylammonium chloride.
3. The method for preparing a low-stress platinum plating layer using a softener high-temperature alloy as described in claim 2, characterized in that, The P-salt platinum plating solution consists of: 2-15 g / L dinitrosodiammineplatinum (calculated as platinum), 10-100 g / L ammonium nitrate, and 5-20 g / L sodium nitrite, wherein the pH is adjusted to 8-12 with ammonia water. The Q-salt platinum plating solution consists of 1~8 g / L of tetraammonium hydrogen phosphate platinum and 10~80 g / L of triammonium phosphate, wherein the pH is adjusted to 8~12 with ammonia water. DNS platinum plating solution consists of 2~8 g / L of platinum-calcium sulfuric acid dinitrosoplatinic acid and 10~100 ml / L of sulfuric acid.
4. The method for preparing a low-stress platinum plating layer using a softener high-temperature alloy as described in claim 2, characterized in that, The concentration of one or more of the following in the platinum plating solution is 0.01–0.5 g / L: dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, and octadecyltrimethylammonium chloride.
5. The method for preparing a low-stress platinum plating layer using a softener high-temperature alloy as described in claim 1, characterized in that, In the process of sequentially performing sandblasting, ultrasonic cleaning, inclusion removal, and activation on high-temperature alloy specimens to obtain the treated high-temperature alloy specimens: High-temperature alloy substrates are sandblasted using white corundum as the abrasive material, with a mesh size of 80-200 mesh, a pressure of 1-4 kg, and a time of 1-5 min. Ultrasonic cleaning is performed on the sandblasted substrate. Sodium hydroxide: 5~20g / L, sodium carbonate: 5~40g / L, trisodium phosphate: 5~40g / L, temperature: 50~70℃, time: 3~15min, ultrasonic frequency: 40~80kHz. The ultrasonically cleaned substrate is subjected to inclusion removal treatment. The inclusion removal solution is composed of one or two of ammonium bifluoride or sodium dihydrogen fluoride, with a content of 20~80g / L, a temperature of 20~35℃, and a time of 2~5min. The substrate after inclusion removal is activated using a hydrochloric acid solution with a concentration of 10-30%, at room temperature for 1-5 minutes.
6. The method for preparing a low-stress platinum plating layer using a softener high-temperature alloy as described in claim 1, characterized in that, In the step of placing the treated high-temperature alloy specimen in a low-stress plating solution and electroplating it to obtain a platinum-plated high-temperature alloy specimen: The activated substrate is subjected to low-stress plating; the plating temperature is 60~98℃, the current density is 1~5A / dm2, and the coating thickness is 3~5 micrometers.