Platinum anode based on titanium alloy surface sintering and preparation method thereof

Abstract

According to the platinum anode based on titanium alloy surface sintering and the preparation method of the platinum anode, a metal platinum coating is prepared on the surface of a titanium alloy carrier through a sintering process and used for preparing the platinum anode for electroplating. A platinum coating is uniformly coated on the surface of a titanium substrate, platinum powder is combined with the titanium substrate through a high-temperature sintering process, and the method overcomes the limitation of the size of a tank body in traditional electroplating and can be used for producing large-size platinum anodes.

Description

Technical Field

[0001] The invention belongs to the technical field of electroplating, and in particular relates to a platinum anode based on titanium alloy surface sintering and a preparation method thereof. Background Art

[0002] At present, the commonly used electroplating anode is a lead anode or a lead-plated stainless steel surface. The commonly used lead anode has poor corrosion resistance and has problems such as a short anode service life. In addition, due to the low hardness and good ductility of lead, the common lead anode is basically a solid cylinder or other simple structure. The large number of bubbles generated during the electroplating process are not easy to dissipate and are easy to gather, resulting in a thin coating or no coating at the gathering location.

[0003] In order to solve this problem, a titanium mesh surface coated with platinum is used as the anode. During the electroplating process, bubbles can quickly pass through the gaps of the mesh anode, and the plated surface is in good condition after plating. The service life of the anode can reach more than 50 times. At present, the platinum coating on the surface of titanium mesh is mainly prepared by electroplating platinum on titanium alloy. Although the platinum electroplating process is stable, it has the following problems: 1. The electroplating tank is small and large-sized titanium alloys cannot be electroplated with platinum; 2. The electroplating speed is extremely slow and the construction period is extremely long; 3. It is expensive. In order to solve this problem, it is necessary to develop a preparation process for platinum coating on the surface of titanium alloys that is cheaper, has a shorter processing cycle, and has smaller size restrictions. Summary of the invention

[0004] The purpose of the present invention is to develop a platinum coating preparation process for titanium mesh surface with lower price, shorter processing cycle and smaller size restriction. The present invention provides a platinum anode based on titanium alloy surface sintering and a preparation method thereof.

[0005] Technical solution of the present invention: In order to achieve the above-mentioned purpose of the invention, according to the first aspect of the present invention, a method for preparing a platinum anode based on sintering of a titanium alloy surface is proposed, which specifically comprises the following steps:

[0006] Step 1: Mechanically processing the titanium alloy raw material to form a titanium alloy carrier;

[0007] Step 2: Pre-treating the surface of the titanium alloy carrier by sandblasting;

[0008] Step 3: performing pickling and corrosion treatment on the surface of the titanium alloy carrier that has been pre-treated by sandblasting in step 2;

[0009] Step 4: washing and drying the surface of the titanium alloy carrier treated by pickling and corrosion in step 3;

[0010] Step 5: sintering the titanium alloy carrier in a sintering furnace at a temperature ranging from 500° C. to 550° C. and a sintering time ranging from 10 min to 20 min;

[0011] Step 6: After cooling the titanium alloy carrier sintered in step 5 to room temperature, use diammonium dinitrosoplatinum solution or chloroplatinic acid solution to uniformly coat the surface of the titanium alloy carrier, put it into a furnace for drying at 100°C, and then sinter it. The sintering temperature range is 500°C-600°C; the sintering time range is 10min-20min, and the heat preservation is 60min.

[0012] The platinum coating is evenly applied on the surface of the titanium substrate, and the platinum powder is combined with the titanium substrate through a high-temperature sintering process. This method overcomes the limitation of the tank size in traditional electroplating and can be used to produce large-sized platinum anodes. At the same time, the platinum sintering process is a technology that sinters platinum particles below the micron level at high temperatures and achieves a close combination of the sintered layer and the substrate through diffusion between atoms. The dense body obtained by high-temperature sintering is a polycrystalline material. The sintering process affects the grain size, grain boundary shape and distribution of the material, and thus affects the performance of the material.

[0013] Step 7: Perform a warpage test on the titanium alloy carrier. The warpage test standard is that the warpage does not exceed 3 mm per meter. The local warpage is leveled by a press.

[0014] Step 8: Repeat steps 6 and 7 until the surface of the titanium alloy carrier reaches the specified coating thickness.

[0015] In a possible embodiment, in step 1, the titanium alloy carrier has a mesh or plate shape.

[0016] In a possible embodiment, in step 2, iron sand is used for sandblasting pretreatment.

[0017] In a possible embodiment, in step 3, the substrate is corroded in an oxalic acid solution for 1-2 hours, then taken out, the titanium oxalate on the surface is quickly rinsed off, and the surface is cleaned; the substrate is dry-sandblasted, pickled for 24-48 hours, and is qualified if it does not turn blue after an iron reagent test for 10 minutes.

[0018] In a possible embodiment, in step 6, in order to prevent thermal warping and deformation, the titanium alloy carrier is pressed under a counterweight steel plate and kept warm in the furnace for 2 hours.

[0019] In a possible embodiment, step 9 is also included, inspection: appearance: no stains, no indentations, no impurities, no more than 2 scratches on each plate, length ≤ 10mm, deep plating shall not expose the substrate; no more than three scratches, area ≤ 9mm 2 , the depth should not expose the substrate. Bonding state: After the coating surface is bonded with colorless transparent tape, no obvious black mark is left, and there is no peeling at the bend when the test piece is bent 180o.

[0020] According to a second aspect of the present invention, a platinum anode based on titanium alloy surface sintering is provided, using the above-mentioned method for preparing a platinum anode based on titanium alloy surface sintering.

[0021] In a possible embodiment, the titanium alloy carrier is in a mesh, plate or rod shape.

[0022] The beneficial effects of the present invention are:

[0023] The invention adopts a method for preparing a platinum anode for electroplating by sintering platinum on the surface of a titanium mesh, thereby greatly shortening the preparation cycle of a platinum mesh anode, reducing the manufacturing cost of the platinum anode and getting rid of the size limitation of the platinum anode. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram of the titanium mesh structure in step 1 of Example 1 of the present invention;

[0025] Figure 2 This is a SEM image of the sintered platinum anode of Example 1 of the present invention. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below in conjunction with embodiments.

[0027] Example 1

[0028] Step 1: Laser cut 21mm*1684mm titanium mesh, grind to remove gray edge burrs, weld firmly, and make the weld beautiful and consistent. Figure 1 As shown: arc length 1684mm, width 21mm, thickness 1.5mm, radius 1239mm;

[0029] Step 2: Sandblast the machined material (iron sand or brown corundum) to ensure that the substrate and the surface coating are firmly bonded. The sand grains should be of good consistency and the surface should be gray and uniform after sandblasting.

[0030] Step 3: Oxalic acid pickling: mainly used for spraying brown corundum substrate to remove the brown corundum attached to the surface, corrode in oxalic acid solution for 1-2 hours, remove, quickly rinse the titanium oxalate on the surface and rinse the surface clean. Industrial hydrochloric acid pickling: mainly used for dry sandblasting substrate, after pickling for 24-48 hours, it is qualified if it does not turn blue after 10 minutes of iron reagent test;

[0031] Step 4: Washing: Wash the surface of the substrate repeatedly with clean water, air dry or dry in an oven. The substrate surface must be free of titanium oxalate deposition, watermarks, stains, rust, and a uniform grayish white color.

[0032] Step 5: Air sintering: Sinter the washed substrate in a sintering furnace at 500°C for 10 minutes. The substrate is qualified if it is uniformly light blue on the surface.

[0033] Step 6: Inspection before coating: The substrate size and process are correct, there are no obvious scratches on the surface of the substrate, and it is qualified if it is uniform light blue;

[0034] Step 7: Coating: Double-sided coating is performed as required; the coating should be applied evenly to make the surface coating uniform and without flow marks. It is then dried in a furnace at 100°C and then sintered in a sintering furnace. After the temperature reaches 500°C, it is sintered for 10 minutes and finally kept warm for 60 minutes.

[0035] Step 8: Hot leveling: At a temperature of 500°C, press the substrate under a counterweight steel plate and keep it in the furnace for 2 hours. It can be taken out of the furnace only when the temperature drops below 300°C and can be taken out only when the temperature is close to being touched by hand. General leveling: If the plate is partially bent, it can be leveled with a press. Leveling standard: ≤3mm per meter.

[0036] Step 9: Coating: Repeat the coating sintering process until the thickness of the sintered titanium layer reaches 2-3um.

[0037] Step 10: Inspection: Appearance: no stains, no indentations, no impurities, no more than 2 scratches on each plate, length ≤10mm, deep plating shall not expose the base material; no more than three scratches, area ≤9mm 2 , the depth should not expose the substrate. Bonding state: After the coating surface is bonded with colorless transparent tape, no obvious black mark is left, and there is no peeling at the bend when the test piece is bent 180o. Figure 2 This is the SEM image of the sintered platinum anode, which shows that the sintered layer and the titanium alloy have a good bonding surface.

[0038] The obtained platinum anode was electroplated with chromium at a current density of 130 min and a coating thickness of 75-80 um. It has been used 30 times and the coating quality is stable.

[0039] Example 2

[0040] Step 1: Mechanically process the titanium alloy raw material as required, including machining the size according to the drawing, grinding to remove gray edge burrs, welding firmly and ensuring consistent welds;

[0041] Step 2: Sandblast the machined material (iron sand) to ensure that the substrate and the surface coating are firmly bonded. The sand grains should be of good consistency and the surface should be gray and uniform after sandblasting.

[0042] Step 3: Oxalic acid pickling: mainly used for spraying brown corundum substrate to remove the brown corundum attached to the surface, corrode in oxalic acid solution for 1-2 hours, remove, quickly rinse the titanium oxalate on the surface and rinse the surface clean. Industrial hydrochloric acid pickling: mainly used for dry sandblasting substrate, after pickling for 24-48 hours, it is qualified if it does not turn blue after 10 minutes of iron reagent test;

[0043] Step 4: Washing: Wash the surface of the substrate repeatedly with clean water, air dry or dry in an oven. The substrate surface must be free of titanium oxalate deposition, watermarks, stains, rust, and a uniform grayish white color.

[0044] Step 5: Air sintering: Sinter the washed substrate in a sintering furnace at 500°C for 10 minutes. The substrate is qualified if it is uniformly light blue on the surface.

[0045] Step 6: Inspection before coating: The substrate size and process are correct, there are no obvious scratches on the surface of the substrate, and it is qualified if it is uniform light blue;

[0046] Step 7: Coating: Double-sided coating is performed as required; the coating should be applied evenly to make the surface coating uniform and without flow marks. It is then dried in a furnace at 100°C and then sintered in a sintering furnace. After the temperature reaches 400°C, it is sintered for 10 minutes and finally kept warm for 60 minutes.

[0047] Step 8: Hot leveling: At a temperature of 500°C, press the substrate under a counterweight steel plate and keep it in the furnace for 2 hours. It can be taken out of the furnace only when the temperature drops below 300°C and can be taken out only when the temperature is close to being touched by hand. General leveling: If the plate is partially bent, it can be leveled with a press. Leveling standard: ≤3mm per meter.

[0048] Step 9: Repeat steps 7 and 8 until the sintered layer thickness reaches 2-3um.

[0049] The surface of the obtained sintered layer is black, the appearance does not meet the requirements, and the coating is unqualified.

[0050] Example 3

[0051] Step 1: Mechanically process the titanium alloy raw material as required, including machining the size according to the drawing, grinding to remove gray edge burrs, welding firmly and ensuring consistent welds;

[0052] Step 2: Sand the machined material with 180-grit sandpaper;

[0053] Step 3: Washing: Wash the surface of the substrate repeatedly with clean water, air dry or dry in an oven. The substrate surface must be free of watermarks, stains, rust, and a uniform grayish white color.

[0054] Step 4: Air sintering: Sinter the washed substrate in a sintering furnace at 500°C for 10 minutes. The substrate is qualified if it is uniformly light blue on the surface.

[0055] Step 5: Inspection before coating: The substrate size and process are correct, there are no obvious scratches on the surface of the substrate, and it is qualified if it is uniformly light blue;

[0056] Step 6: Coating: Double-sided coating is carried out as required; the coating should be applied evenly to make the surface coating uniform and without flow marks. It is dried in a furnace at 100°C and then sintered in a sintering furnace. After the temperature reaches 500°C, it is sintered for 10 minutes and finally kept warm for 60 minutes.

[0057] Step 7: Hot leveling: At a temperature of 500°C, press the substrate under a counterweight steel plate and keep it in the furnace for 2 hours. It can be taken out of the furnace only when the temperature drops below 300°C and can be taken out only when the temperature is close to being touched by hand. General leveling: If the plate is partially bent, it can be leveled with a press. Leveling standard: ≤3mm per meter.

[0058] Step 8: Repeat steps 7 and 8 until the sintered layer thickness reaches 2-3um.

[0059] After the obtained platinum anode is used 2-3 times, the surface platinum sintered layer peels off, and the bonding strength between the sintered layer and the substrate does not meet the requirements.

Claims

1. A method for preparing a platinum anode based on titanium alloy surface sintering, characterized in that: The specific steps include: Step 1: Mechanically processing the titanium alloy raw material to form a titanium alloy carrier; Step 2: Pre-treating the surface of the titanium alloy carrier by sandblasting; Step 3: performing pickling and corrosion treatment on the surface of the titanium alloy carrier that has been pre-treated by sandblasting in step 2; Step 4: washing and drying the surface of the titanium alloy carrier treated by pickling and corrosion in step 3; Step 5: sintering the titanium alloy carrier in a sintering furnace at a temperature of 500-550° C. and a sintering time of 10-20 min; Step 6: After cooling the titanium alloy carrier sintered in step 5 to room temperature, a diammonium dinitrosoplatinum solution or a chloroplatinic acid solution is used to uniformly coat the surface of the titanium alloy carrier, and the carrier is dried in a furnace at 100-120° C. to remove moisture in the solution, and then sintered. The sintering temperature range is 500° C.-600° C.; the sintering time range is 10-20 min, and the heat preservation time is 60-75 min; Step 7: Perform a warpage test on the titanium alloy carrier. The warpage test standard is that the warpage does not exceed 3 mm per meter. The local warpage is leveled by a press. Step 8: Repeat steps 6 and 7 until the surface of the titanium alloy carrier reaches the specified coating thickness.

2. The method for preparing a platinum anode based on titanium alloy surface sintering according to claim 1 is characterized in that: In the step 1, the titanium alloy carrier has a mesh, plate or rod shape.

3. The method for preparing a platinum anode based on titanium alloy surface sintering according to claim 1 is characterized in that: In the step 2, iron sand is used for sandblasting pretreatment.

4. The method for preparing a platinum anode based on titanium alloy surface sintering according to claim 1 is characterized in that: In the step 3, the substrate is corroded in oxalic acid solution for 1-2 hours, then taken out, the titanium oxalate on the surface is quickly washed off, and the surface is cleaned; the substrate is dry-sandblasted, pickled for 24-48 hours, and is qualified if it does not turn blue after 10 minutes of iron reagent test.

5. The method for preparing a platinum anode based on titanium alloy surface sintering according to claim 1 is characterized in that: In step 6, in order to prevent thermal warping and deformation, the titanium alloy carrier is pressed under a counterweight steel plate and kept warm in the furnace for 2 hours.

6. The method for preparing a platinum anode based on titanium alloy surface sintering according to claim 1, characterized in that: It also includes step 9, inspection: Appearance: no stains, no indentations, no impurities, no more than 2 scratches on each plate, length ≤10mm, deep plating shall not expose the substrate; no more than three scratches, area ≤9mm 2 , the depth should not expose the substrate. Bonding state: After the coating surface is bonded with colorless transparent tape, no obvious black mark is left, and there is no peeling at the bend when the test piece is bent 180°.

7. A platinum anode based on titanium alloy surface sintering, characterized in that: A method for preparing a platinum anode based on titanium alloy surface sintering as described in any one of claims 1 to 6.

8. The platinum anode based on titanium alloy surface sintering according to claim 7, characterized in that: The titanium alloy carrier is in a mesh or plate shape.

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