Method for treating cemented carbide material

Abstract

The application provides a processing method of a cemented carbide material, comprising the following steps: cooling a cemented carbide sample from 20 DEG C to -190 DEG C within 210-420 min; after the cooling, keeping the sample at -190 DEG C in a liquid nitrogen atmosphere for 2 h; after the keeping, heating and tempering the sample to 30 DEG C and keeping the sample at 30 DEG C for 1 h. The processing method provided by the application increases the number of refined grains of the processed cemented carbide material and increases the content of grains with a particle size less than 0.5 μm.

Description

Technical Field

[0001] This invention relates to the technical field of cemented carbide processing, and more specifically to a method for processing cemented carbide materials. Background Technology

[0002] Cemented carbide is an alloy material made from hard compounds of refractory metals and binder metals through powder metallurgy. In mass production, the toughness, durability, and stability of domestically produced cemented carbide materials are affected, and their lifespan, wear resistance, and machining strength still lag behind those of European and American cutting tools. This is mainly due to the lower number of refined grains in the powder metallurgy-processed material. Summary of the Invention

[0003] In order to overcome the shortcomings of the prior art, the present invention aims to provide a method for processing cemented carbide materials, which increases the number of refined grains and the content of grains with a diameter of less than 0.5 μm in the processed cemented carbide materials.

[0004] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0005] A method for processing cemented carbide materials includes the following steps:

[0006] The cemented carbide samples were cooled from 20°C to -190°C within 210-420 minutes.

[0007] After cooling, keep warm in a liquid nitrogen atmosphere at -190℃ for 2 hours;

[0008] After heat preservation, the temperature is raised to 30℃ and tempered for 1 hour.

[0009] In some possible implementations, during the cooling step, the cemented carbide sample is cooled at a rate of 1 °C / min over 210 min.

[0010] In some possible implementations, during the cooling step, the cemented carbide sample is cooled at a rate of 0.5 °C / min over 420 min.

[0011] In some possible implementations, the tempering time is 700 minutes.

[0012] In some possible embodiments, the cemented carbide sample comprises WC, Co, TiC, and TaC, wherein the mass fraction of WC is 84%, the mass fraction of Co is 6%, and the combined mass fraction of TiC and TaC is 10%.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0014] In this application, by synergistically combining cooling parameters, liquid nitrogen atmosphere holding parameters, and heating and tempering parameters, the number of refined grains in the treated cemented carbide material is increased, and the content of grains with a diameter of less than 0.5 μm is increased.

[0015] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0016] Figure 1 This is a flowchart illustrating a method for processing cemented carbide material grains according to an embodiment of this application.

[0017] Figure 2 SEM images of sample 1 are provided for Example 1;

[0018] Figure 3 SEM images of sample 2 are provided for Example 2;

[0019] Figure 4 SEM image of untreated sample 3;

[0020] Figure 5 The histogram of grain size statistics for sample 1;

[0021] Figure 6 The histogram of grain size statistics for sample 2;

[0022] Figure 7 The histogram of grain size for sample 3. Detailed Implementation

[0023] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0025] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0026] One embodiment of this application provides a method for refining the grain size of a cemented carbide material, comprising the following steps.

[0027] Step S101: Cool the cemented carbide sample from 20°C to -190°C over 210-420 minutes. For example, liquid nitrogen can be used for cooling.

[0028] In some embodiments, during the cooling step, the cemented carbide sample is cooled at a rate of 1 °C / min over 210 min.

[0029] In some embodiments, during the cooling step, the cemented carbide sample is cooled at a cooling rate of 0.5 °C / min over 420 min.

[0030] The combination of the above-mentioned cooling time and cooling rate is conducive to further increasing the proportion of smaller grains.

[0031] In some embodiments, the cemented carbide sample comprises WC (tungsten carbide), Co (cobalt), TiC (titanium carbide), and TaC (tantalum carbide), wherein the mass fraction of WC is 84%, the mass fraction of Co is 6%, and the combined mass fraction of TiC and TaC is 10%.

[0032] Step S102: After cooling, keep warm in a liquid nitrogen atmosphere at -190℃ for 2 hours.

[0033] Step S103: After holding at the initial temperature, heat the furnace to 30°C and hold for 1 hour. For example, the heating and tempering operation can be performed using furnace heating.

[0034] In some embodiments, the tempering time is 700 min.

[0035] In this application, by synergistically combining cooling parameters, liquid nitrogen atmosphere holding parameters, and heating and tempering parameters, the number of refined grains in the treated cemented carbide material is increased, and the content of grains with a diameter of less than 0.5 μm is increased.

[0036] Example 1

[0037] The cemented carbide sample was cooled from room temperature (20°C) to -190°C (using liquid nitrogen atmosphere) within 210 min at a cooling rate of 1°C / min. After cooling, it was held at -190°C in liquid nitrogen atmosphere for 2 h. Following this, it underwent tempering, tempering for 700 min to 30°C and holding for 1 h to obtain sample 1. Heating can be performed using furnace heating. The cemented carbide sample comprises WC, Co, TiC, and TaC, with WC having a mass fraction of 84%, Co having a mass fraction of 6%, and the combined mass fraction of TiC and TaC being 10%.

[0038] Example 2

[0039] The cemented carbide sample was cooled from room temperature (20°C) to -190°C (using liquid nitrogen atmosphere) within 420 min at a cooling rate of 0.5°C / min. After cooling, it was held at -190°C in liquid nitrogen atmosphere for 2 h. Following this, it underwent tempering, tempering for 700 min to 30°C and holding for 1 h, yielding sample 2. Heating can be performed using furnace heating. The cemented carbide sample comprises WC, Co, TiC, and TaC, with WC comprising 84% by mass, Co comprising 6% by mass, and the combined mass fraction of TiC and TaC comprising 10%.

[0040] The treated samples 1 and 2, and the untreated sample 3 (with the same composition as samples 1 and 2) were mounted using epoxy resin as the mounting powder. The samples were then ground with a diamond grinding wheel to achieve optimal flatness on the working surface, followed by polishing with a 1μm diamond. Finally, they were etched using Murakami reagent (10g potassium ferricyanide, 10g sodium hydroxide or potassium hydroxide and 100ml water) for 3-6 minutes. The etchant was rinsed off with pure water, and the samples were then blotted dry with absorbent paper before microscopic observation and grain imaging. Grain size was evaluated according to the average grain size (intercept method) of metals in GB / T 6394-2017.

[0041] The grain structure of samples 1, 2, and 3 is as follows: Figures 2 to 7 As shown, analysis Figures 5 to 7The grain distribution shows that in sample 1, the number of grains with a diameter of 0.1 μm is 1 (0.2%), the number of grains with a diameter of 0.2 μm is 29 (4.4%), the number of grains with a diameter of 0.3 μm is 124 (18.8%), the number of grains with a diameter of 0.4 μm is 161 (24.5%), the number of grains with a diameter of 0.5 μm is 185 (28.1%), and the number of grains with a diameter of 0.6 μm is 79 (%). The number of grains with a diameter of 12.0% was 48 (7.3%), the number of grains with a diameter of 0.7μm was 15 (2.3%), the number of grains with a diameter of 0.8μm was 7 (1.1%), the number of grains with a diameter of 0.9μm was 6 (0.9%), the number of grains with a diameter of 1μm was 2 (0.3%), the number of grains with a diameter of 1.2μm was 1 (0.2%), and the total number of fine grains was 658. In Sample 2, the number of grains with a diameter of 0.1 μm was 0, the number of grains with a diameter of 0.2 μm was 25 (4.0%), the number of grains with a diameter of 0.3 μm was 149 (24.0%), the number of grains with a diameter of 0.4 μm was 170 (27.3%), the number of grains with a diameter of 0.5 μm was 119 (19.1%), the number of grains with a diameter of 0.6 μm was 75 (12.1%), the number of grains with a diameter of 0.7 μm was 51 (8.2%), the number of grains with a diameter of 0.8 μm was 18 (2.9%), the number of grains with a diameter of 0.9 μm was 11 (1.8%), the number of grains with a diameter of 1 μm was 3 (0.5%), the number of grains with a diameter of 1.1 μm was 0, the number of grains with a diameter of 1.2 μm was 1 (0.2%), and the total number of fine grains was 622. In Sample 3, the number of grains with a diameter of 0.1 μm was 0, the number of grains with a diameter of 0.2 μm was 14 (2.4%), the number of grains with a diameter of 0.3 μm was 94 (16.3%), the number of grains with a diameter of 0.4 μm was 158 (27.3%), the number of grains with a diameter of 0.5 μm was 142 (24.6%), the number of grains with a diameter of 0.6 μm was 80 (13.8%), the number of grains with a diameter of 0.7 μm was 39 (6.7%), the number of grains with a diameter of 0.8 μm was 23 (4.0%), the number of grains with a diameter of 0.9 μm was 14 (2.4%), the number of grains with a diameter of 1 μm was 7 (1.2%), the number of grains with a diameter of 1.1 μm was 6 (1.0%), the number of grains with a diameter of 1.2 μm was 1 (0.2%), and the total number of fine grains was 578. Similarly, it can be concluded that the number of fine grains in the cemented carbide obtained by the method of this application increases, and the proportion of grains with a diameter of less than 0.5 μm increases.

[0042] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A method for processing cemented carbide materials, characterized in that, Includes the following steps: The cemented carbide sample was cooled from 20°C to -190°C within 210-420 min. The cemented carbide sample included WC, Co, TiC and TaC, with WC having a mass fraction of 84%, Co having a mass fraction of 6%, and TiC and TaC having a combined mass fraction of 10%. After cooling, keep warm in a liquid nitrogen atmosphere at -190℃ for 2 hours; After heat preservation, the temperature is raised to 30℃ and tempered for 1 hour.

2. The processing method as described in claim 1, characterized in that, In the cooling step, the cemented carbide sample was cooled at a rate of 1℃ / min over 210 minutes.

3. The processing method as described in claim 1, characterized in that, In the cooling step, the cemented carbide sample was cooled at a rate of 0.5℃ / min over 420 minutes.

4. The processing method as described in claim 1, characterized in that, The heating and tempering time is 700 minutes.

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