CN110509114A - A grinding and polishing method for tungsten alloy - Google Patents

Abstract

The invention discloses a grinding and polishing method for tungsten alloy, which belongs to the technical field of ultra-precision processing of metal alloys. The specific steps are: (1) Rough grinding: select deionized water as the grinding fluid, set the flow rate of the polishing fluid to 6-12ml/min, select a diamond-bonded abrasive pad with a particle size of 20-50 μm for grinding, and set the grinding processing time to 20-40min. (2) Fine grinding: the particle size of the diamond abrasive is 5-20 μm, the processing time is set to 40-60 min, and the rest of the processing parameters are the same as the rough grinding. (3) Polishing: The polishing liquid contains silica sol, PH regulator, deionized water, the volume fraction of silica sol abrasive is 10-25%, and the pH value is 2-5; the flow rate of the polishing liquid is set at 4-6ml/min, and the grinding The pressure is set to 20-40kpa, and the grinding processing time is set to 1.5-2.5h. The processing time of the whole grinding and polishing process is less than 5 hours, and the surface roughness Ra of the polished tungsten alloy is less than 10nm, which can meet the precision requirements in the actual processing field and realize the ultra-precision processing of tungsten alloy.

Description

A grinding and polishing method for tungsten alloy

technical field

The invention belongs to the technical field of ultra-precision machining of metal alloys, and relates to an ultra-precision machining method for metal alloy grinding and polishing, in particular to a tungsten alloy grinding and ultra-precision polishing method.

Background technique

Tungsten alloy is an alloy with hard tungsten as the dominant phase and softer metals such as nickel, iron, copper, and cobalt as the matrix phase. Due to its special material structure, tungsten alloy not only has high density, high strength, excellent thermal properties, excellent corrosion resistance and radiation resistance, but also has better ductility and machinability than pure tungsten. Due to its good comprehensive properties, the application of tungsten alloy in the field of ultra-precision machining has gradually attracted people's attention. In the field of aerospace, tungsten alloys are mainly used to manufacture gyroscope rotors, shock absorbers, counterweight balances, etc. High-precision processing quality is conducive to ensuring the stability of parts. In the field of military industry, as an excellent material for shielding γ-ray and other radiation, tungsten alloy has been widely used in the production of precision components such as radioactive source containers, collimators, medical shields and nuclear shields. At the same time, tungsten alloys are used as targets or key components in precision physical experiments such as spallation sources, nuclear energy, and shock detonation physical experiments. Good surface quality is conducive to improving the accuracy of experimental results. Therefore, the surface grinding and polishing technology of tungsten alloy is very important.

However, there are few invention patents on the tungsten alloy grinding and polishing process, and a set of mature and standardized process standards has not yet been formed. At present, the processing method for tungsten alloy is still dominated by traditional turning. However, due to the high hardness, high brittleness, and large elastic deformation of tungsten alloys, large cutting forces and high cutting temperatures are generated during processing, resulting in severe tool wear and difficult processing. In response to the above problems, some researchers have conducted research on cutting tools and crafting techniques, and have improved the turning tungsten alloy process by introducing auxiliary processing technology and replacing wear-resistant cutting tools, such as ultrasonic assisted dry turning, elliptical vibration cutting method, Ultrasonic vibration cutting method based on gas-liquid atomization cooling, etc. Although the above improved methods have achieved certain results, the quality and precision of the machined surface are still difficult to meet the requirements of ultra-precision machining. Considering that the grinding and polishing process is currently the main means for processing various solid materials to achieve precise dimensions, ultra-accurate shapes, and extremely low surface roughness, it is urgent to propose a grinding and polishing process for tungsten alloys.

Contents of the invention

In order to overcome the shortcomings of the above-mentioned prior art and provide a reference for the precision machining of tungsten alloys in the future, the purpose of the present invention is to provide a grinding and polishing method for tungsten alloys, which can quickly and effectively make the surface roughness of tungsten alloys microscopically Reach the mirror level below 10nm, and there are no obvious scratches on the surface that can be measured by naked eyes.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A grinding and polishing method for tungsten alloys is implemented based on a grinding and polishing device for tungsten alloys. First, a tungsten alloy sample 3 is bonded to a disc fixture 4 with paraffin, and a grinding/polishing pad 2 is bonded to a stainless steel workbench 1. The stainless steel workbench 1 is driven by a stepping motor. During the processing, the stainless steel workbench 1 and the sample 3 rotate around their respective axes. The polishing liquid device is installed above the grinding/polishing pad 2. During the grinding and polishing process, the polishing liquid 6 drops on the grinding/polishing pad 2 to realize auxiliary processing for grinding and polishing. The grinding and polishing method includes the configuration of the grinding liquid, the selection of the grinding and polishing parameters and the selection of the grinding and polishing pad, and the specific steps are:

1) Rough grinding (neutral polishing liquid)

The grinding fluid is deionized water, and the flow rate of the polishing fluid is set at 6-12ml/min. Consolidated abrasive grinding, the abrasive is made of diamond abrasive grains, the particle size of the abrasive is 20-50 μm, and the grinding pad is made of diamond-consolidated abrasive grains. The speed of the processing disc is set to 60-120rmp, the speed of the workpiece is set to 50-110rmp, and the grinding pressure is set to 40-80kpa by adding a counterweight or weight. The processing time is set at 20-40min. After rough grinding, wash the surface of the workpiece with water and dry it with an air gun.

2) Fine grinding (neutral polishing liquid)

The particle size of the finely ground diamond abrasive is 5-20 μm, the processing time is set at 40-60 minutes, and other parameter settings (such as the flow rate of the polishing liquid, the speed of the processing disc and the workpiece, etc.) are the same as the rough grinding process. After lapping, wash the surface of the workpiece with water and dry it with an air gun.

3) Configure mixed polishing liquid

The mixed polishing solution includes a pH regulator, a silica sol solution and deionized water, the mixed solution is guaranteed to have a pH value of 2-5, and the concentration of the silica sol is set at 10-25 vol.%. The pH regulator is one or more of citric acid crystals, malic acid crystals, and phosphoric acid solutions; the silica sol solution contains silicon dioxide abrasive grains with an abrasive grain diameter of 65-80 nm.

4) Polishing (acid polishing solution)

The polishing liquid prepared in step 3) is dropped on the polishing pad, and the flow rate of the polishing liquid is set at 4-6 ml/min. For free abrasive polishing, use silicon dioxide abrasive grains with a particle size of 65-80nm as the abrasive, and use IC 1000/SubaⅣ as the polishing pad. The processing disc speed is set to 50-80rmp, the workpiece speed is set to 40-70rmp, and the grinding pressure is set to 20-40kpa by adding a counterweight plate or weight. The processing time is set to 1.5-2.5h. After polishing, wash the surface of the workpiece with water and dry it with an air gun. The roughness Ra of the polished tungsten alloy surface is less than 10nm.

The beneficial effect of the present invention is: the tungsten alloy automatic grinding and polishing method is realized by using a simple device, and the surface roughness Ra of the polished tungsten alloy is less than 10nm. The processing time of the entire grinding and polishing process is less than 5 hours, which can meet the precision requirements in the actual processing field and realize the ultra-precision processing of tungsten alloys.

Description of drawings

Fig. 1 is the processing schematic diagram of grinding and polishing process;

Fig. 2 is a flow chart of the grinding and polishing process.

In the figure: 1 stainless steel workbench; 2 grinding/polishing pad; 3 tungsten alloy sample; 4 disc fixture; 5 counterweight plate; 6 polishing liquid.

Detailed ways

The specific implementation manner of the present invention will be described in detail below in conjunction with the technical solutions.

Tungsten alloy sample 3 is made of 95W-3.5Ni-1.5Fe alloy, which is made by sintering reduced tungsten, carbonyl nickel and carbonyl iron powders with average diameters of 2.5μm, 2.5μm, and 3.5μm respectively, and the processing size is Φ15 ×7mm ³ . Use paraffin to evenly bond three tungsten alloy samples 3 to the circumference of the fixture 4 with a diameter of Φ100 mm, and use the breeding disc 5 to perform pressure loading on the samples 3 . The grinding pad 2 is bonded on the stainless steel workbench 1 of the grinding and polishing machine. The polishing liquid device is installed above the polishing pad 2, and the polishing liquid 6 drops on the polishing pad 2 to realize auxiliary processing for grinding and polishing.

1) The polishing liquid is deionized water, and the flow rate of the polishing liquid is set to 8.5ml/min. Consolidated abrasives are used for grinding, and the abrasives are diamond abrasive grains with a particle size of 15-25 μm, and the grinding pad 2 is a diamond consolidated abrasives grinding pad. The processing disc speed is set to 70rmp, the workpiece speed is set to 60rmp, and the grinding loading pressure is set to 59kpa. The processing time was set to 30min. After rough grinding, wash the surface of the workpiece with water and dry it with an air gun.

2) Replace the grinding pad to ensure that the particle size of the finely ground diamond abrasive is 5-10 μm, and the processing time is set to 40 minutes. Other parameters such as the flow rate of the polishing liquid, the speed of the processing disc and the workpiece speed are set in the same way as the rough grinding process. After lapping, wash the surface of the workpiece with water and dry it with an air gun.

3) Configure mixed polishing solution: the mixed polishing solution includes acid solution, silica sol solution and deionized water, wherein the acid solution is regulated by citric acid crystals, and the pH value of the mixed solution is set to 4. The silica sol solution contains silica abrasive grains with a diameter of 72 nm, and the concentration of the silica sol is set at 15 vol.%.

4) Replace the polishing pad, drop the above-mentioned polishing liquid on the polishing pad, and set the flow rate of the polishing liquid to 5.5ml/min. For free abrasive polishing, the abrasive is made of silicon dioxide abrasive grains, and the polishing pad is made of IC 1000/SubaⅣ. The processing disc rotation speed is set to 60rmp, the workpiece rotation speed is set to 50rmp, and the polishing loading pressure is set to 29kpa. The processing time is set to 1.5h. After polishing, wash the surface of the workpiece with water and dry it with an air gun. The roughness of the polished tungsten alloy surface reaches Ra 7nm.

The content described in the embodiments of this specification is only an enumeration of the implementation forms of the inventive concept. The protection scope of the present invention should not be regarded as limited to the specific forms stated in the embodiments. The protection scope of the present invention also includes those skilled in the art. Equivalent technical means conceivable according to the concept of the present invention.

Claims (6)

1. a kind of abrasive polishing method of tungsten alloy, which is realized based on the grinding and polishing device of tungsten alloy, throw Light liquid device is mounted on above grinding/polishing pad, and tungsten alloy exemplar is bonded on disk clamp, and grinding/polishing pad is bonded in not It becomes rusty on steel workbench, stainless steel workbench is driven by stepper motor；Stainless steel workbench and exemplar are respectively around axis in process Rotation, polishing fluid are dropped on grinding/polishing pad, which is characterized in that the abrasive polishing method following steps:

1) it slightly grinds

Lapping liquid is deionized water, and polishing fluid flow set is 6~12ml/min；Consolidating material and diamond abrasive grinding, grinding pad choosing With through diamond fixed grain grinding pad；Processing disk rotating speed is set as 60~120rmp, and workpiece rotational frequency is set as 50~110rmp, Grinding pressure is 40~80kpa；Process time is set as 20~40min；Workpiece surface is washed with water after the completion of slightly grinding, uses air gun Drying；

2) lappingout

The diamond abrasive partial size of lappingout is less than diamond abrasive partial size in step 1), and process time is set as 40~60min, His parameter setting is identical as process is slightly ground；Workpiece surface is washed with water after the completion of lappingout, is dried up with air gun；

3) mixed polishing solution is configured

Mixed polishing solution includes PH regulator, silicon sol solution and deionized water, and mixed solution guarantees pH value 2~5, and silicon is molten The concentration of glue is arranged in 10~25vol.%；Contain silica abrasive grain in the silicon sol solution；

4) it polishes

The polishing fluid that step 3) configures is dropped on polishing pad, polishing fluid flow set is 4~6ml/min；Free abrasive is thrown Light, it is the silica abrasive grain of 65~80nm that abrasive material, which selects partial size, and polishing pad selects IC 1000/Suba IV；Processing disk rotating speed is set It is set to 50~80rmp, workpiece rotational frequency is set as 40~70rmp, and grinding pressure is 20~40kpa；Process time is set as 1.5- 2.5h；Workpiece surface is washed with water after the completion of polishing, is dried up with air gun, the roughness Ra on the tungsten alloy surface after polishing is less than 10nm。

2. a kind of abrasive polishing method of tungsten alloy according to claim 1, which is characterized in that by increase balancing disk or Grinding pressure is arranged in the mode of counterweight.

3. a kind of abrasive polishing method of tungsten alloy according to claim 1, which is characterized in that golden in the step 1) The partial size of hard rock abrasive material is 20~50 μm.

4. a kind of abrasive polishing method of tungsten alloy according to claim 1, which is characterized in that golden in the step 2) The partial size of hard rock abrasive material is 5~20 μm.

5. a kind of abrasive polishing method of tungsten alloy according to claim 1, which is characterized in that PH in the step 3) Regulator is the mixing of one or more of Citric acid crystal, apple acid crystal, phosphoric acid solution.

6. a kind of abrasive polishing method of tungsten alloy according to claim 1, which is characterized in that silicon in the step 3) Silica abrasive grain partial size in sol solution is 65~80nm.