Antibacterial hard alloy and preparation method thereof

Abstract

The invention discloses an antibacterial hard alloy and a preparation method thereof, the hard alloy comprises the following components: 18.0-26.0 wt% of Co, 6.0-14.5 wt% of Ni, 2.1-7.8 wt% of AgCu28 and the balance of WC, and the grain size is 2-4 grades. The preparation method comprises the steps that S1, WC powder, Co powder, Ni powder and AgCu28 powder are fully mixed and ground, and raw materials are obtained and screened; and S2, the powder obtained in the step S1 is subjected to compression molding, hot isostatic pressing sintering is conducted at the temperature of 1400 DEG C, and the antibacterial hard alloy is obtained. According to the antibacterial hard alloy, the antibacterial and bacteriostatic performance and the high-strength and high-wear-resisting performance are met at the same time, on the basis of the hard alloy, the antibacterial capacity of the material is improved by adding Ag and Cu, meanwhile, the compatibility of alloy elements is improved by adding Ni, and the comprehensive mechanical performance of the antibacterial hard alloy is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of industrial metal material preparation technology, and in particular to an antibacterial hard alloy and its preparation method. Background Technology

[0002] Cemented carbide, due to its high strength, red hardness, and wear resistance, is widely used in cutting tools and wear-resistant parts. Existing cemented carbide materials mainly consist of a hard phase (WC) and a binder phase (Co). The good wettability of Co to WC ensures the alloy possesses excellent overall mechanical properties. However, in the food and medical fields, antibacterial and bacteriostatic properties are crucial, thus placing higher demands on the antibacterial capabilities of equipment and tools. Currently available Cu- or Ag-containing stainless steels lack sufficient wear resistance and have short service lives in food and medical applications, requiring further solutions. Summary of the Invention

[0003] The purpose of this invention is to provide an antibacterial cemented carbide and its preparation method to solve the above-mentioned technical problems.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] An antibacterial cemented carbide, comprising 18.0–26.0 wt% Co, 6.0–14.5 wt% Ni, and 2.1–7.8 wt% AgCu. 28 With the remainder of WC, the grain size is 2 to 4 grades.

[0006] As a further aspect of the present invention, the cemented carbide composition includes 22.0 wt% Co, 7.6 wt% Ni, and 3.6 wt% AgCu. 28 And the margin of WC.

[0007] A method for preparing an antibacterial cemented carbide includes the following steps:

[0008] S1: Mix WC powder, Co powder, Ni powder and AgCu 28 The powder is thoroughly mixed and ground to obtain the raw material, which is then sieved.

[0009] S2: The powder obtained in S1 is pressed into shape and then subjected to hot isostatic pressing sintering at 1400℃ to obtain the antibacterial hard alloy.

[0010] As a further embodiment of the present invention, the grinding is wet grinding, and the process conditions are as follows: the ball-to-material ratio is (3-5):1, the ball milling time is 20h-36h, the wet grinding media includes alcohol and paraffin, the amount of paraffin is 2%-2.2% of the total mass of the ingredients, and the mass-volume ratio of alcohol to the total amount of ingredients is (0.25-0.35)L:1Kg; after wet grinding, the mixture is screened and then precipitated for more than 8h to allow the alcohol to evaporate, and then pressed and dried.

[0011] As a further aspect of the present invention, in step S2, the sintering includes three stages: dewaxing, pre-sintering, and sintering. The dewaxing stage is set at a temperature of 350–450°C and a holding time of 6–8 hours; the pre-sintering stage is set at a temperature of 600°C–750°C.

[0012] The pre-firing holding time is 3 to 6 hours; the sintering temperature is set at 1350℃ to 1450℃ during the sintering stage, and the sintering holding time is 1 to 2 hours.

[0013] As a further embodiment of the present invention, the WC powder has a particle size of 15–25 μm, the Co powder has a particle size of 1.5–2.0 μm, the Ni powder has a particle size of 1.5–2.5 μm, and the AgCu powder has a particle size of 1.5–2.5 μm. 28 The particle size is 1.0–3.5 μm.

[0014] The prepared antibacterial cemented carbide has a hardness of 72-80 HRA and a bending strength of 2400-2700 MPa. It also exhibits good wear resistance and toughness.

[0015] The beneficial effects of this invention are: this invention simultaneously satisfies antibacterial and bacteriostatic properties as well as high strength and high wear resistance. Based on cemented carbide, the antibacterial ability of the material is improved by adding Ag and Cu, while Ni is added to improve the compatibility of alloying elements, thus ensuring the comprehensive mechanical properties of the antibacterial cemented carbide. Detailed Implementation

[0016] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] An antibacterial cemented carbide, comprising 18.0–26.0 wt% Co, 6.0–14.5 wt% Ni, and 2.1–7.8 wt% AgCu. 28 The cemented carbide composition includes 22.0 wt% Co, 7.6 wt% Ni, and 3.6 wt% AgCu. The grain size is 2–4. 28 And the margin of WC.

[0018] A method for preparing an antibacterial cemented carbide includes the following steps:

[0019] S1: Mix WC powder, Co powder, Ni powder and AgCu 28 The powder is thoroughly mixed and ground to obtain raw materials, which are then sieved. The grinding is a wet grinding process with the following conditions: the ball-to-material ratio is (3-5):1, the ball milling time is 20-36 hours, the wet grinding media include alcohol and paraffin, the amount of paraffin is 2%-2.2% of the total mass of the ingredients, and the mass-volume ratio of alcohol to the total mass of the ingredients is (0.25-0.35) L:1 kg. After wet grinding, the mixture is screened and then allowed to settle for more than 8 hours to allow the alcohol to evaporate. Finally, it is pressed, shaped, and dried.

[0020] S2: The powder obtained in S1 is pressed into shape and then subjected to hot isostatic pressing sintering at 1400℃ to obtain the antibacterial cemented carbide. The sintering includes three stages: dewaxing, pre-sintering, and sintering. The dewaxing stage is set at a dewaxing temperature of 350-450℃ and a holding time of 6-8 hours; the pre-sintering stage is set at a pre-sintering temperature of 600-750℃ and a holding time of 3-6 hours; the sintering stage is set at a sintering temperature of 1350-1450℃ and a holding time of 1-2 hours.

[0021] The WC powder has a particle size of 15–25 μm, the Co powder has a particle size of 1.5–2.0 μm, the Ni powder has a particle size of 1.5–2.5 μm, and the AgCu powder has a particle size of… 28 The particle size is 1.0–3.5 μm. The prepared antibacterial cemented carbide has a hardness of 72–80 HRA and a bending strength of 2400–2700 MPa.

[0022] Table 1 shows the content of each component in the embodiments of the present invention, which includes 22.0 wt% Co, 7.6 wt% Ni, and 3.6 wt% AgCu. 28 And the margin of WC.

[0023] Table 1 Content of each component in antibacterial cemented carbide

[0024] Component content Co Ni <![CDATA[AgCu 28 ]]> WC Example (wt.%) 22.0 7.6 3.6 margin

[0025] The mechanical properties of the cemented carbide samples of this invention were tested, and their hardness was 76.9 HRA and bending strength was 2640 MPa, which are far higher than those of traditional stainless steel antibacterial materials (tensile strength of about 800 MPa), thus exhibiting better strength and wear resistance. The cemented carbide samples of this invention were contacted with Escherichia coli bacterial solution for 24 hours and then eluted and cultured. Colony growth was observed, and no obvious colonies were found on the surface of the antibacterial cemented carbide.

[0026] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An antibacterial cemented carbide, characterized in that, The cemented carbide component comprises 18.0-26.0 wt% Co, 6.0-14.5 wt% Ni, 2.1-7.8 wt% AgCu 28 and the balance WC, having a grain size of 2-4.

2. The antibacterial cemented carbide according to claim 1, characterized in that, The cemented carbide component comprises 22.0 wt% Co, 7.6 wt% Ni, 3.6 wt% AgCu 28 and the balance WC.

3. A method of producing the antibacterial cemented carbide according to any one of claims 1-2, characterized in that, Includes the following steps: S1 : WC powder, Co powder, Ni powder and AgCu 28 powder are thoroughly mixed and ground to obtain a raw material, and sieved; S2: The powder obtained in S1 is pressed into shape and then subjected to hot isostatic pressing sintering at 1400℃ to obtain the antibacterial hard alloy.

4. A method of producing cemented carbide according to claim 3, c h a r a c t e r i s e d in that The grinding is wet grinding, and the process conditions are as follows: the ball-to-material ratio is (3-5):1, the ball milling time is 20h-36h, the wet grinding media includes alcohol and paraffin, the amount of paraffin is 2%-2.2% of the total mass of the ingredients, and the mass-volume ratio of alcohol to the total amount of ingredients is (0.25-0.35)L:1Kg; after wet grinding, the mixture is screened and then allowed to settle for more than 8h to allow the alcohol to evaporate, and then it is pressed and dried.

5. A method of producing cemented carbide according to claim 3, c h a r a c t e r i s e d in that In step S2, the sintering includes three stages: dewaxing, pre-sintering, and sintering. The dewaxing stage is set at a temperature of 350–450°C and a holding time of 6–8 hours. The pre-sintering stage is set at a temperature of 600°C–750°C. The pre-firing holding time is 3 to 6 hours; the sintering temperature is set at 1350℃ to 1450℃ during the sintering stage, and the sintering holding time is 1 to 2 hours.

6. The method for preparing cemented carbide according to claim 3, characterized in that, The WC powder has a particle size of 15–25 μm, the Co powder has a particle size of 1.5–2.0 μm, the Ni powder has a particle size of 1.5–2.5 μm, and the AgCu powder has a particle size of… 28 The particle size is 1.0–3.5 μm.

7. The method for preparing cemented carbide according to claim 3, characterized in that, The prepared antibacterial cemented carbide has a hardness of 72-80 HRA and a bending strength of 2400-2700 MPa.