A method for reducing the wettability of liquid copper on the surface of refractory metal at high temperature and a tool and die for manufacturing refractory metal

Abstract

The present invention relates to a method for reducing the wettability of liquid copper on the surface of a refractory metal at high temperature, which comprises the following steps: pre-treating the surface of the refractory metal, and forming a micro-protrusion structure on the surface of the refractory metal by femtosecond laser processing. The present invention effectively reduces the high-temperature wettability of liquid copper on the surface of the refractory metal at high temperature by processing the micro-protrusion structure on the surface of the refractory metal, thereby reducing the adhesion performance of liquid copper on the tungsten surface at high temperature, and utilizing the refractory characteristics of the refractory metal, according to the Cassie theory at high temperature, to improve the wetting angle of liquid copper on the surface of the refractory metal at high temperature, thereby laying a foundation for the application of refractory metal in the field of copper liquid forming. For example, when performing liquid copper casting forming, liquid copper additive manufacturing, etc., copper droplets may splash around. At this time, it is more appropriate to use refractory metal for protection. After the copper solidifies, it is not easy to connect with the refractory metal and is easy to clean.

Description

Technical Field

[0001] The invention relates to the technical field of laser surface treatment, and in particular to a method for reducing the wettability of liquid copper on the surface of a refractory metal at high temperature and a tool and die made of the refractory metal. Background Art

[0002] High-temperature wettability refers to the interaction and contact characteristics between the solid surface and the liquid under high temperature conditions, which directly affects the contact performance of two materials in different states under high temperature conditions. At present, the method for judging high-temperature wettability is mainly through the contact angle method, which measures the contact angle of the droplet on the solid surface to judge the wettability. The smaller the contact angle, the better the wettability.

[0003] Metal tungsten is the metal material with the highest melting point. At high temperatures, tungsten and copper are incompatible and difficult to bond at the interface. Further reducing the wettability of liquid copper on the surface of solid tungsten at high temperatures is expected to effectively prevent liquid copper from adhering to the tungsten surface or reduce the bonding force of copper after it adheres to the tungsten surface. This is of great significance for the application of metal tungsten in liquid forming fields such as copper casting and liquid copper additive manufacturing. Summary of the invention

[0004] Based on this, the purpose of the present invention is to provide a method for reducing the wettability of liquid copper on the surface of refractory metal at high temperature and a tool and mold made of refractory metal, which can reduce the wettability of liquid copper on the surface of refractory metal, and is of great significance for the application of refractory metal in the field of copper liquid forming.

[0005] To achieve the above object, the present invention adopts the following technical solutions: The present invention first provides a method for reducing the wettability of liquid copper on the surface of a refractory metal at high temperature, which comprises the following steps: pretreating the surface of the refractory metal, and processing the surface of the refractory metal to form a micro-protrusion structure.

[0006] The present invention forms a micro-protrusion structure on the surface of a refractory metal, thereby effectively reducing the high-temperature wettability of liquid copper on the surface of the refractory metal at high temperature, thereby reducing the adhesion performance of liquid copper on the tungsten surface at high temperature. The refractory characteristics of the refractory metal are utilized, and according to the Cassie theory at high temperature, the wetting angle of liquid copper on the surface of the refractory metal at high temperature is improved, thereby laying a foundation for the application of refractory metal in the field of copper liquid forming. For example, when performing liquid copper casting and liquid copper additive manufacturing, copper droplets may splash around. At this time, it is more appropriate to use refractory metal for protection. After the copper solidifies, it is not easy to connect with the refractory metal and is easy to clean.

[0007] As a further improvement of the above solution of the present invention, the micro-protrusion structure is formed by performing femtosecond laser processing on the surface of the refractory metal.

[0008] As a further improvement of the above solution of the present invention, the femtosecond laser processing adopts a galvanometer scanning laser processing system.

[0009] As a further improvement of the above-mentioned scheme of the present invention, the laser power of the femtosecond laser processing is 10-100W, the spot diameter is 20-60μm, the scanning rate is 200-1500mm / s, the linear filling spacing is 15-120μm, and the number of scans is 50-750 times, so as to achieve controllable preparation of the surface structure of difficult-to-process metals (such as metal tungsten).

[0010] As a further improvement of the above solution of the present invention, the micro-protrusion structure is a femtosecond laser induced surface periodic structure (LIPPS structure).

[0011] As a further improvement of the above solution of the present invention, the refractory metal is metal tungsten.

[0012] As a further improvement of the above solution of the present invention, the pretreatment includes: grinding and polishing the surface of the refractory metal with sandpaper, and then ultrasonically cleaning the ground refractory metal in alcohol to remove contaminants attached to the surface of the refractory metal.

[0013] The present invention also provides a tooling die made of refractory metal, which is processed and formed by the above-mentioned method of reducing the wettability of liquid copper on the surface of refractory metal at high temperature.

[0014] The present invention also provides an application of the tooling die made of the refractory metal as described above in the field of copper liquid forming.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention forms a micro-protrusion structure on the surface of a refractory metal, thereby effectively reducing the high-temperature wettability of liquid copper on the surface of the refractory metal at high temperature, thereby reducing the adhesion performance of liquid copper on the tungsten surface at high temperature, and utilizing the refractory characteristics of the refractory metal. According to the Cassie theory at high temperature, the wetting angle of liquid copper on the surface of the refractory metal at high temperature is improved, thereby laying a foundation for the application of refractory metals in the field of copper liquid forming. For example, when performing liquid copper casting and liquid copper additive manufacturing, copper droplets may splash around. At this time, it is more appropriate to use refractory metal for protection. After the copper solidifies, it is not easy to connect with the refractory metal and is easy to clean.

[0016] 2. The present invention uses femtosecond laser processing to form a micro-convex structure on the surface of a refractory metal. It has ultra-fast processing, simple procedures, a wide range of applications, and is green and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a scanned photo of the surface morphology of the finished product of metal tungsten in Example 1 of the present invention; Figure 2 This is a scanned photo of the surface morphology of the finished product of metal tungsten in Example 2 of the present invention; Figure 3 This is a morphological diagram of the surface of the finished product of liquid copper processed by metal tungsten in Example 1; Figure 4 This is a morphological diagram of the surface of the finished product of liquid copper processed by metal tungsten in Example 2; Figure 5 This is a morphology diagram of the surface of the finished product of liquid copper on the metal tungsten of the comparative example. DETAILED DESCRIPTION

[0018] For ease of understanding of the present invention, the present invention will be described more fully below in conjunction with specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0020] Example 1 This embodiment provides a method for reducing the wettability of liquid copper on a tungsten surface at high temperature, which includes the following steps: a. Use sandpaper to grind and polish the surface of metal tungsten; b. Place the polished tungsten metal sample in an alcohol solution for ultrasonic cleaning to remove pollutants attached to the tungsten surface; c. Place the metal tungsten sample on a femtosecond laser processing platform and perform femtosecond processing on the metal tungsten sample based on a galvanometer scanning processing system. Set the laser power of the galvanometer scanning processing system to 40 W, the spot diameter to 30 μm, the scanning rate to 500 mm / s, the linear filling spacing to 20 μm, and the number of scans to 50 times to obtain a metal tungsten product with a LIPPS structure formed on the surface.

[0021] Figure 1 This is a scanning photo of the surface morphology of the finished metal tungsten product obtained in this embodiment. It can be seen that after the metal tungsten is laser processed, a LIPPS structure is generated on the surface.

[0022] Example 2 This embodiment provides a method for reducing the wettability of liquid copper on a tungsten surface at high temperature, which includes the following steps: a. Use sandpaper to grind and polish the surface of metal tungsten; b. Place the polished tungsten metal sample in an alcohol solution for ultrasonic cleaning to remove pollutants attached to the tungsten surface; c. Place the metal tungsten sample on a femtosecond laser processing platform and perform femtosecond processing on the metal tungsten sample based on a galvanometer scanning processing system. Set the laser power of the galvanometer scanning processing system to 32W, the spot diameter to 30μm, the scanning rate to 1000mm / s, the linear filling spacing to 100μm, and the number of scans to 750 times to obtain a metal tungsten product with a LIPPS structure formed on the surface.

[0023] Figure 2 This is a scanning photo of the surface morphology of the finished metal tungsten product obtained in this embodiment. It can be seen that after the metal tungsten is laser processed, a LIPPS structure is generated on the surface.

[0024] Comparative Example a. Use sandpaper to grind and polish the surface of metal tungsten; b. Put the polished tungsten metal sample into an alcohol solution for ultrasonic cleaning to remove the pollutants attached to the tungsten surface and obtain the finished tungsten metal product.

[0025] Test Case A copper ball with a diameter of 2 mm was placed on the surface of the metal tungsten processed products obtained in Example 1, Example 2, and the comparative example, and heated to 1200°C at a rate of 5°C / s using a high-temperature contact angle measuring device. The temperature was kept for 20 minutes, and the morphology of the molten liquid copper on the surface of each metal tungsten processed product was photographed by a digital camera. The morphology of the liquid copper on the surface of the metal tungsten processed products obtained in Example 1, Example 2, and the comparative example is shown as follows: Figure 3 , Figure 4 , Figure 5 shown.

[0026] from Figure 3 It can be seen that the contact angle between the liquid copper and the metal tungsten processed product obtained in Example 1 is 133.6°, indicating that the surface wettability of the liquid copper on the metal tungsten processed product obtained in Example 1 is very low at high temperature.

[0027] from Figure 4 It can be seen that the contact angle between the liquid copper and the metal tungsten processed product obtained in Example 2 is 129.4°, indicating that the wettability of the liquid copper on the surface of the metal tungsten processed product obtained in Example 2 at high temperature is very low.

[0028] from Figure 5 It can be seen that the contact angle between the liquid copper and the metal tungsten processed product obtained in the comparative example (without ultrafast laser processing) is 102.4°.

[0029] In summary, it can be seen that the contact angle between the liquid copper and the metal tungsten processed products obtained in Example 1 and Example 2 is greater than the contact angle between the liquid copper and the metal tungsten processed products obtained in the comparative example, indicating that the wettability of the liquid copper on the metal tungsten surface after ultrafast laser processing in Example 1 and Example 2 is significantly reduced.

[0030] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0031] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for reducing the wettability of liquid copper on the surface of a refractory metal at high temperature, characterized in that: It includes the following steps: The surface of the refractory metal is pretreated, and a micro-protrusion structure is formed on the surface of the refractory metal.

2. The method for reducing the wettability of liquid copper on the surface of refractory metal at high temperature according to claim 1, characterized in that: The micro-protrusion structure is formed by performing femtosecond laser processing on the surface of the refractory metal.

3. The method for reducing the wettability of liquid copper on the surface of refractory metal at high temperature according to claim 2, characterized in that: The femtosecond laser processing adopts a galvanometer scanning laser processing system.

4. The method for reducing the wettability of liquid copper on the surface of refractory metal at high temperature according to claim 2, characterized in that: The laser power of the femtosecond laser processing is 10-100W, the spot diameter is 20-60μm, the scanning rate is 200-1500mm / s, the linear filling spacing is 15-120μm, and the number of scans is 50-750 times.

5. The method for reducing the wettability of liquid copper on the surface of refractory metal at high temperature according to claim 2, characterized in that: The micro-protrusion structure is a femtosecond laser-induced surface periodic structure.

6. The method for reducing the wettability of liquid copper on the surface of refractory metal at high temperature according to claim 1, characterized in that: The refractory metal is metal tungsten.

7. The method for reducing the wettability of liquid copper on the surface of refractory metal at high temperature according to claim 1, characterized in that: The pretreatment includes: grinding and polishing the surface of the refractory metal with sandpaper, and then placing the ground refractory metal in alcohol for ultrasonic cleaning.

8. A tooling die made of refractory metal, characterized in that: The method for reducing the wettability of liquid copper on the surface of refractory metal at high temperature as described in any one of claims 1 to 7 is used for processing and forming.

9. Use of a tooling die made of refractory metal as claimed in claim 8 in the field of copper liquid forming.

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