CN115846669A - Metal ceramic cutting tool and manufacturing method thereof - Google Patents

Abstract

The invention discloses a metal ceramic cutting tool and a manufacturing method thereof, and relates to the technical field of powder metallurgy. The metal ceramic cutting tool consists of titanium carbide particles and martensitic stainless steel, wherein the volume fraction of the titanium carbide particles is 40-60%. Compared with a martensitic stainless steel cutting tool, the metal ceramic cutting tool has the advantages of high hardness, high strength, light weight and wear resistance, and meanwhile has more excellent fracture toughness and more resistance to falling than a pure ceramic cutting tool. The manufacturing method of the metal ceramic cutting tool comprises the steps of firstly carrying out low-energy ball milling on titanium carbide particles and martensitic stainless steel powder, then carrying out banburying with an organic high-analysis binder to prepare a feed, then injecting into a cutting tool green body, and finally carrying out degreasing, sintering, heat treatment and edging to obtain the metal ceramic cutting tool. The metal ceramic cutting tool product manufactured by the method has the advantages of high dimensional precision, excellent comprehensive performance, high batch production efficiency, less or no subsequent machining and low manufacturing cost.

Description

A metal-ceramic cutting tool and its manufacturing method

technical field

The invention relates to the technical field of powder metallurgy, in particular to a cermet cutting tool and a manufacturing method thereof.

Background technique

At present, stainless steel is mainly used for cutting tools such as hardware knives and scissors, scalpels, and beauty pliers, especially martensitic stainless steel with high hardness. However, the corrosion resistance of martensitic stainless steel is poor, and with the improvement of the quality of life, people put forward higher and higher requirements for cutting tools, such as: beautiful appearance, light weight and wear resistance, etc. For this reason, many kitchen knives and other cutting tools based on ceramics such as zirconia and alumina have appeared on the market in recent years. This kind of cutting tool has a white jade color, beautiful appearance, high hardness, light weight and sharp cutting edge, which is a high-end product. But the fly in the ointment is that due to the inherent brittleness of ceramics, this type of cutting tool has extremely poor toughness and cannot withstand large impacts or bending moments, so it is not resistant to falling and is very easy to jump.

In view of this, the present invention is proposed.

Contents of the invention

One of the purposes of the present application is to provide a cermet cutting tool to solve the above-mentioned background technology. In the prior art, the density of the martensitic stainless steel cutting tool is relatively high and the wear resistance needs to be further improved; while the toughness of the ceramic cutting tool is extremely poor. The problem of resistance to falling and easy jumping of blades. Compared with martensitic stainless steel cutting tools, the cermet cutting tool has higher hardness, light weight and wear resistance, and has better fracture toughness and more drop resistance than pure ceramic cutting tools.

The second object of the present application is to provide a method for manufacturing the above-mentioned cermet cutting tool. The cermet product produced by the method has high dimensional accuracy, excellent comprehensive performance, high batch production efficiency, little or no subsequent machining, and low manufacturing cost.

In order to achieve the above object, the application provides the following technical solutions:

In a first aspect, the present application provides a cermet cutting tool. The cermet cutting tool is composed of titanium carbide particles and martensitic stainless steel, and the density is less than 6.7 g/cm ³ .

In an optional embodiment, the volume percentage of titanium carbide particles is 40-60%.

In an alternative embodiment, the titanium carbide particle size is less than 3 μm.

In a second aspect, the present application provides a method for manufacturing a cermet cutting tool according to the aforementioned embodiment, including the following steps:

1) Low-energy ball milling of titanium carbide particles and martensitic stainless steel powder to obtain mixed powder;

2) After kneading the mixed powder and organic polymer binder in an internal mixer for 1 to 2 hours, cooling, crushing and granulating to obtain feed;

3) The feed material is injected into the designed cutting tool mold cavity on the injection machine, and the cutting tool green body is obtained by demoulding;

4) After degreasing, high-temperature sintering, heat treatment and sharpening of the cutting tool green body, the cermet cutting tool product is obtained.

In an optional embodiment, the low-energy ball mill is a stirring ball mill with a rotation speed of 50-150 rpm and a ball-to-material ratio of 3:1.

In an optional embodiment, the mass percentage of the organic polymer binder in the feed is 9%-13%.

In an optional embodiment, the organic polymer binder includes the following components in mass percentage: polyoxymethylene 86%, polypropylene 7%, ethylene-vinyl acetate copolymer 3%, solid paraffin 2%, hard Zinc fatty acid 1.5% and antioxidant 0.5%.

In an optional embodiment, the high-temperature sintering is carried out under vacuum, the sintering temperature is 1300-1400° C., and the holding time is 1-2 hours.

The beneficial effects of the application include:

1) This application reduces the density of the cutting tool and improves the wear resistance of the cutting tool by adding titanium carbide particles to the martensitic stainless steel cutting tool and controlling its content and particle size. Compared with martensitic stainless steel cutting tools, the cermet cutting tools of the present application are lighter in weight, higher in hardness, and more wear-resistant. At the same time, they have better fracture toughness than pure ceramic cutting tools, are not easy to chip, and are more resistant to falling.

2) This application uses metal injection molding technology to manufacture cermet cutting tools. The process flow includes seven steps of powder mixing, banburying, injection, degreasing, sintering, heat treatment and sharpening. The cermet cutting tools manufactured by this technology have high dimensional accuracy, excellent comprehensive performance, high mass production efficiency, little or no subsequent machining, and low cost.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and thus It should be regarded as a limitation on the scope, and those skilled in the art can also obtain other related drawings based on these drawings without creative work.

Fig. 1 is the microstructural figure of the cermet cutting tool that adopts embodiment 3 to manufacture;

Figure 2 is a schematic diagram of the process flow of the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Those who do not indicate the specific conditions in the examples are carried out according to the conventional conditions or the conditions suggested by the manufacturer. The reagents or instruments used were not indicated by the manufacturer, and they were all conventional products that could be purchased from the market.

The cermet cutting tool provided by the present application and its manufacturing method are described in detail below.

The present application proposes a cermet cutting tool, which is composed of titanium carbide particles and martensitic stainless steel with a volume percentage of 40-60%.

For reference, the volume percentage of titanium carbide particles in cermet cutting tools can be exemplarily 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49% , 50%, 51%, 52%, 53%, 54%, 45%, 56%, 57%, 58%, 59% or 60%, etc., can also be other arbitrary values within the range of 40-60%.

The particle size of the above-mentioned titanium carbide particles is less than 3 μm, preferably 0.5-3 μm, such as 0.5 μm, 0.8 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm or 3 μm, or any other value within the range of 0.5-3 μm.

When the volume percentage of the titanium carbide particles is 40-60%, the density of the cermet cutting tool can be ensured to be less than 6.7 g/cm ³ .

Continuing from the above, the cermet cutting tool provided by this application is to add titanium carbide particles to the martensitic stainless steel cutting tool, and control its content and particle size, which can reduce the density of the cutting tool and improve the wear resistance of the cutting tool. Compared with martensitic stainless steel cutting tools, cermet cutting tools are lighter, harder, and more wear-resistant. At the same time, they have better fracture toughness than pure ceramic cutting tools, are not easy to chip, and are more resistant to falling.

Correspondingly, the present application also provides a method for manufacturing the above-mentioned cermet, comprising the following steps:

In the first step, titanium carbide particles and martensitic stainless steel powder are low-energy ball milled to obtain a mixed powder.

Specifically, titanium carbide particles and martensitic stainless steel powder are mixed by stirring low-energy ball milling at a speed of 50-150rpm (such as 50rpm, 60rpm, 70rpm, 80rpm, 90rpm, 100rpm, 110rpm, 120rpm, 130rpm, 140rpm or 150rpm, etc.). The material ratio is 3 to 1.

By mixing stainless steel powder and titanium carbide particles under the above conditions by low-energy ball milling, on the one hand, the agglomerates of titanium carbide particles can be dispersed to make the titanium carbide particles more uniformly dispersed; on the other hand, the stirring effect of low-energy ball milling can make the stainless steel powder Fully mixed with titanium carbide particles to ensure uniform structure of sintered cermet cutting tools.

In the second step, the mixed powder and the organic polymer binder are kneaded in an internal mixer for 1 to 2 hours, cooled, crushed, and granulated to obtain feed.

Specifically, the organic polymer binder includes the following components in mass percentage: polyoxymethylene 86%, polypropylene 7%, ethylene-vinyl acetate copolymer 3%, solid paraffin 2%, zinc stearate 1.5% and antioxidant 0.5%.

Using the above-mentioned organic polymer binder formula, the organic polymer binder can be better coated on the surface of the metal powder particles, and it is more conducive to the removal of the binder during subsequent degreasing, thereby ensuring the sintered cutting tool products The residues of impurities such as carbon and oxygen are low, which makes the sintered product have high performance.

Further, the mass proportion of the organic polymer binder in the feed is 9%-13%.

As a reference, the mass percentage of organic polymer bonding in the feed can be 9%, 10%, 11%, 12% or 13% for example, and can also be other values within the range of 9% to 13%. any value. When the mass fraction of the binder is 9% to 13%, the feeding material has good fluidity, the mold filling effect is good, the density of the green injection body is high, and the sintered cutting tool product has better dimensional accuracy and density.

The third step is to design the mold according to the drawing of the cutting tool product, then feed the material and inject it into the designed cutting tool mold cavity on the injection machine, and then demould to obtain the cutting tool green body. For specific conditions, reference may be made to related prior art, and details are not repeated here.

Further, the cutting tool green body is degreased, high-temperature sintered, heat treated and sharpened to obtain a cermet cutting tool product.

Specifically, the high-temperature sintering is carried out under vacuum, the sintering temperature is 1300-1400° C., and the holding time is 1-2 hours.

For reference, the sintering temperature may be 1300°C, 1320°C, 1340°C, 1360°C, 1380°C or 1400°C, etc., or any other value within the range of 1300-1400°C.

The holding time can be exemplarily 1 h, 1.5 h or 2 h, and can also be any other value within the range of 1-2 h.

By adopting the above sintering conditions, the cutting tool product can be uniformly shrunk without being deformed or collapsed, and high density can be obtained, thereby ensuring higher performance of the cutting tool product.

For other specific conditions, reference may be made to related prior art, and details are not repeated here.

Based on the above, the method for manufacturing cermet cutting tools provided by this application can realize mass production of cermet cutting tools, with high efficiency and low cost; the manufactured cermet cutting tools have high density, uniform structure, high dimensional accuracy, and excellent comprehensive performance , and the finished product can be finished with little or no subsequent machining.

The characteristics and performance of the present invention will be described in further detail below in conjunction with the examples.

Example 1

This embodiment provides a cermet cutting tool, which is manufactured by the following method:

Step (1): Select titanium carbide powder with a particle size of 3.0 μm and 420 martensitic stainless steel powder according to volume fractions of 60% and 40%, respectively, and weigh them for future use.

Step (2): Pour the weighed titanium carbide powder and 420 martensitic stainless steel powder into the stirring low-energy ball mill, the ball-to-material ratio is 3 to 1, the speed is set to 50rpm, and the mixed powder is taken out after ball milling for 5 hours for later use .

Step (3): polyoxymethylene, polypropylene, ethylene-vinyl acetate copolymer, solid paraffin, zinc stearate and antioxidant are 86%, 7%, 3%, 2%, 1.5% and 0.5% according to mass fraction % for material preparation.

Step (4): Weigh the binder and the mixed powder respectively according to the mass fractions of 13% and 87% for future use.

Step (5): The internal mixer is heated up to 190°C, and then the weighed mixed powder and the organic polymer binder are poured into the internal mixer, kneaded for 1 to 2 hours, cooled, crushed, and granulated to obtain feeding.

Step (6): Inject the feed material into the designed cavity of the cutting tool mold through the injection machine, and demould to obtain the cutting tool green body;

Step (7): After degreasing the green body of the cutting tool, place it in a vacuum sintering furnace for vacuum sintering at a sintering temperature of 1400°C and a holding time of 1 hour, and obtain a sintered body of the cutting tool after cooling in the furnace.

Step (8): The sintered cutting body is heat-treated and sharpened to obtain a cermet cutting tool product.

Example 2

This embodiment provides a cermet cutting tool, which is manufactured by the following method:

Step (1): Select titanium carbide powder with a particle size of 0.5 μm and 420 martensitic stainless steel powder according to volume fractions of 50% and 50%, respectively, and weigh them for future use.

Step (2): Pour the weighed titanium carbide powder and 420 martensitic stainless steel powder into the stirring low-energy ball mill, the ball-to-material ratio is 3 to 1, and the speed is set to 150rpm. After ball milling for 5 hours, take out the mixed powder for later use .

Step (3): polyoxymethylene, polypropylene, ethylene-vinyl acetate copolymer, solid paraffin, zinc stearate and antioxidant are 86%, 7%, 3%, 2%, 1.5% and 0.5% according to mass fraction % for material preparation.

Step (4): Weigh the binder and the mixed powder respectively according to the mass fractions of 11% and 89% for future use.

Step (5): The internal mixer is heated up to 190°C, and then the weighed mixed powder and the organic polymer binder are poured into the internal mixer, kneaded for 1 to 2 hours, cooled, crushed, and granulated to obtain feeding.

Step (6): Inject the feed material into the designed cavity of the cutting tool mold through the injection machine, and demould to obtain the cutting tool green body;

Step (7): After degreasing the green body of the cutting tool, place it in a vacuum sintering furnace for vacuum sintering at a sintering temperature of 1300° C. and a holding time of 2 hours. After cooling in the furnace, the sintered body of the cutting tool is obtained.

Step (8): The sintered cutting body is heat-treated and sharpened to obtain a cermet cutting tool product.

Example 3

This embodiment provides a cermet cutting tool, which is manufactured by the following method:

Step (1): Titanium carbide powder with a particle size of 2.0 μm and 420 martensitic stainless steel powder are selected and weighed according to volume fractions of 40% and 60% respectively for future use.

Step (2): Pour the weighed titanium carbide powder and 420 martensitic stainless steel powder into the stirring low-energy ball mill. The ball-to-material ratio is 3 to 1, and the speed is set to 100rpm. After 5 hours of ball milling, take out the mixed powder for later use .

Step (3): polyoxymethylene, polypropylene, ethylene-vinyl acetate copolymer, solid paraffin, zinc stearate and antioxidant are 86%, 7%, 3%, 2%, 1.5% and 0.5% according to mass fraction % for material preparation.

Step (4): Weigh the binder and the mixed powder respectively according to the mass fractions of 9% and 91% for future use.

Step (5): The internal mixer is heated up to 190°C, and then the weighed mixed powder and the organic polymer binder are poured into the internal mixer, kneaded for 1 to 2 hours, cooled, crushed, and granulated to obtain feeding.

Step (6): Inject the feed material into the designed cavity of the cutting tool mold through the injection machine, and demould to obtain the cutting tool green body;

Step (7): After degreasing the green body of the cutting tool, place it in a vacuum sintering furnace for vacuum sintering at a sintering temperature of 1350°C and a holding time of 1.5 hours, and obtain a sintered body of the cutting tool after cooling in the furnace.

Step (8): The sintered cutting body is heat-treated and sharpened to obtain a cermet cutting tool product.

Comparative example 1

The difference between this comparative example and Example 3 is that no titanium carbide particles are added to the 420 martensitic stainless steel powder.

That is, adopt the same metal injection molding process as the embodiment to manufacture 420 martensitic stainless steel cutting tools.

Comparative example 2

BAYCO zirconia ceramic kitchen knives purchased by Jingdong Supermarket.

Test example 1

Taking Examples 1-3 and Comparative Example 1-2 as examples, test according to "GB/T3850", "GB/T 231" and "GB/T 21143" respectively to the obtained cermet cutting tools, martensitic stainless steel The cutting tools and BAYCO zirconia ceramic kitchen knives were tested for density, compactness, hardness and fracture toughness, and the results are shown in Table 1.

Table 1 Test results

As can be seen from Table 1, the density of the cermet cutting tool obtained in the embodiment of the present application has lower density and higher hardness than the martensitic stainless steel cutting tool obtained in Comparative Example 1; and the cermet cutting tool obtained in the embodiment of the present application Compared with Comparative Example 2, it has higher fracture toughness.

To sum up, this application adds titanium carbide particles on the basis of traditional martensitic stainless steel, and controls its content and particle size, and uses metal injection molding technology to manufacture low-density cermet cutting tools, while improving the hardness of the cutting tools . Compared with martensitic stainless steel cutting tools, the cermet cutting tools of the present application are lighter in weight, higher in hardness, and more wear-resistant. At the same time, they have better fracture toughness than pure ceramic cutting tools, are not easy to chip, and are more resistant to falling. At the same time, cermet cutting tools have high dimensional accuracy, excellent comprehensive performance, high mass production efficiency, little or no subsequent machining, and low cost.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (5)

1. A cermet cutting tool, characterized in that the cermet cutting tool is composed of titanium carbide particles and martensitic stainless steel, with a density of less than 6.7g/cm ³ . Preferably, the volume percentage of the titanium carbide particles is 40-60%. Preferably, the particle size of the titanium carbide is less than 3 μm. 2. The manufacturing method of a kind of cermet cutting tool according to claim 1, is characterized in that comprising the following steps: 1) Low-energy ball milling of titanium carbide particles and martensitic stainless steel powder to obtain mixed powder; 2) After kneading the mixed powder and organic polymer binder in an internal mixer for 1 to 2 hours, cooling, crushing and granulating to obtain feed; 3) The feed material is injected into the designed cutting tool mold cavity on the injection machine, and the cutting tool green body is obtained by demoulding; 4) After degreasing, high-temperature sintering, heat treatment and sharpening of the cutting tool green body, the cermet cutting tool product is obtained. 3. The manufacturing method of the cermet cutting tool according to claims 1 and 2, characterized in that: The low-energy ball mill is a stirring ball mill with a rotation speed of 50-150 rpm and a ball-to-material ratio of 3:1. 4. The manufacturing method of the cermet cutting tool according to claims 1 and 2, characterized in that: The mass percent content of the organic polymer binder in the feed is 9%-13%. Preferably, the organic polymer binder includes the following components in mass percentage: polyoxymethylene 86%, polypropylene 7%, ethylene-vinyl acetate copolymer 3%, solid paraffin 2%, zinc stearate 1.5% and antioxidant 0.5%. 5. The method of manufacturing cermet cutting tools according to claims 1 and 2, characterized in that: the high-temperature sintering is vacuum sintering, the sintering temperature is 1300-1400°C, and the holding time is 1-2 hours.

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