CN109439992B

CN109439992B - NbC-Ni-Mo2C high-temperature hard alloy and preparation method thereof

Info

Publication number: CN109439992B
Application number: CN201811236774.9A
Authority: CN
Inventors: 张可夫
Original assignee: Zhuzhou Sanxin Cemented Carbide Production Co ltd
Current assignee: Zhuzhou Sanxin Cemented Carbide Production Co ltd
Priority date: 2018-10-23
Filing date: 2018-10-23
Publication date: 2020-09-29
Anticipated expiration: 2038-10-23
Also published as: CN109439992A

Abstract

The invention relates to a hard alloyThe technical field of materials and discloses NbC-Ni-Mo₂C high-temperature hard alloy and a preparation method thereof. NbC-Ni-Mo₂The C high-temperature hard alloy has better high-temperature performance, and can effectively reduce crater abrasion generated during the processing of iron-based workpiece materials. Adding Mo on the basis of NbC-8Ni₂After C, the high-temperature performance of the material is effectively improved, and the hardness and the fracture toughness are also obviously improved in physical property detection data.

Description

NbC-Ni-Mo2C high-temperature hard alloy and preparation method thereof

Technical Field

The invention relates to the technical field of hard alloy materials, in particular to NbC-Ni-Mo₂C high-temperature hard alloy and a preparation method thereof.

Background

Cemented carbide is an alloy material made from a hard compound of refractory metals and a binder metal by a powder metallurgy process. The hard alloy has a series of excellent performances of high hardness, wear resistance, good strength and toughness, heat resistance, corrosion resistance and the like, particularly high hardness and wear resistance, basically keeps unchanged even at the temperature of 500 ℃, and still has high hardness at the temperature of 1000 ℃. Cemented carbide is widely used as a tool material, and can also be used for cutting difficult-to-machine materials such as heat-resistant steel, stainless steel, high manganese steel, tool steel, and the like.

The hard alloy has high hardness, strength, wear resistance and corrosion resistance, is widely applied in many fields, and the market demand of the hard alloy is continuously increased.

The performance of the existing hard alloy begins to decline in a working environment above 800 ℃, and the iron-based workpiece is subjected to crater abrasion during processing, so that the workpiece is damaged, and the processing quality and the service life of a cutter are influenced. It is necessary to develop a new type of high temperature cemented carbide which is stable in performance at high temperatures and does not deteriorate in physical properties.

Disclosure of Invention

Aiming at the defects in the prior art, provides NbC-Ni-Mo₂C high-temperature hard alloy. Adding Mo into NbC-8Ni₂C can improve the high-temperature performance, hardness and fracture toughness of the material.

The invention also provides NbC-Ni-Mo₂A preparation method of the high-temperature hard alloy material.

In order to solve the technical problems, the invention adopts the technical scheme that:

NbC-Ni-Mo₂C high-temperature hard alloy is based on NbC-8Ni and added with Mo₂C, mixing the following components in percentage by weight:

NbC 84～88％

Ni 8％

Mo₂C 4～8％。

NbC-Ni-Mo₂The preparation method of the C high-temperature hard alloy comprises the following specific preparation steps:

s1, according to the NbC-Ni-Mo₂C, proportioning the high-temperature hard alloy, and wet grinding to obtain slurry;

s2, drying the slurry, mixing the dried powder with glue, then pressing and molding, and then degumming and sintering to obtain NbC-Ni-Mo₂C high-temperature hard alloy.

Further, the fisher particle size of the NbC powder of step S1 is 2 μm.

Further, the fernber particle size of the Ni powder in step S1 is 2 μm.

Further, the ball-to-material ratio of the wet grinding in the step S1 is 3: 1.

Further, the wet milling medium for wet milling in step S1 is industrial alcohol with a water content of 5 wt%.

Furthermore, the wet grinding time in the step S1 is 20-40 h.

Further, the temperature of the degumming and sintering in the step S2 is 1400-1600 ℃.

Further, the sintering time of the degumming and sintering in the step S2 is 1-3 h.

Compared with the prior art, the beneficial effects are:

the invention provides NbC-Ni-Mo₂The preparation method of the C high-temperature hard alloy is simple and convenient and easy to operate. The invention provides NbC-Ni-Mo₂The C high-temperature hard alloy has excellent high-temperature performance, and Mo is added₂After C, the fracture toughness and hardness of the material are obviously enhanced. Disclosed is NbC-Ni-Mo₂The C high-temperature hard alloy can effectively prevent the damage to the iron-based workpiece in the field of material processing, and has good red hardness above 800 ℃.

Detailed Description

Example 1

s1, mixing according to the weight ratio, wherein the content of NbC powder is 88 wt%, the content of Ni powder is 8 wt%, and Mo₂The content of the C powder is 4 wt%, and the total amount of the prepared mixture is 1 Kg. The mixture is added into a ball mill cylinder with the volume of 2L after being mixed, 3Kg of hard alloy grinding rod is added, industrial alcohol with the water content of 5 wt% is added as a wet grinding medium, the wet grinding time is 30h, and the wet grinding is carried out to obtain the slurry.

S2, drying the slurry obtained in the step S1, mixing the dried powder with glue, then pressing and molding, degumming and sintering at 1480 ℃, and preserving heat for 1h to obtain NbC-Ni-Mo₂C high-temperature hard alloy.

The obtained NbC-Ni-Mo₂The specification of the C high-temperature hard alloy test strip is 5.25mm × 6.5.5 mm × 20mm, and the obtained test strip is subjected to hardness and fracture toughness tests.

Example 2

The present example refers to the preparation method of example 1, and the difference from example 1 is that the mixture ratio is: the content of NbC powder is 86 wt%, the content of Ni powder is 8 wt%, and Mo₂The content of the C powder is 6 wt%, and the total amount of the prepared mixture is 1 Kg; the wet milling time is 20h, the degumming and sintering temperature is 1400 ℃, and the heat preservation time is 2 h.

Example 3

The present example refers to the preparation method of example 1, and the difference from example 1 is that the mixture ratio is: 84 wt% of NbC powder, 8 wt% of Ni powder and Mo₂The content of the C powder is 8 wt%, and the total amount of the prepared mixture is 1 Kg; the wet milling time is 40h, the degumming sintering temperature is 1600 ℃, and the heat preservation time is 3 h.

Comparative example 1

The comparative example refers to the preparation method of example 1, and is different from example 1 in that the mixture ratio is as follows: the NbC powder content is 92 wt%, the Ni powder content is 8 wt%, and the total amount of the prepared mixture is 1 Kg.

Comparative example 2

Comparative exampleThe preparation method of the mixed material is as in example 1, and the difference of the preparation method and the example 1 is that the mixture ratio of the mixed material is as follows: 88 wt% of WC powder, 8 wt% of Ni powder and Mo₂The content of the C powder is 4 wt%, and the total amount of the prepared mixture is 1 Kg.

Comparative example 3

The comparative example refers to the preparation method of example 1, and is different from example 1 in that the mixture ratio is as follows: WC powder content of 86 wt%, Ni powder content of 8 wt%, Mo₂The content of the C powder is 6 wt%, and the total amount of the prepared mixture is 1 Kg.

Comparative example 4

The comparative example refers to the preparation method of example 1, and is different from example 1 in that the mixture ratio is as follows: 84 wt% of WC powder, 8 wt% of Ni powder and Mo₂The content of the C powder is 8 wt%, and the total amount of the prepared mixture is 1 Kg.

Comparative example 5

The comparative example refers to the preparation method of example 1, and is different from example 1 in that the mixture ratio is as follows: 90 wt% of NbC powder, 8 wt% of Ni powder and Mo₂The content of the C powder is 2 wt%, and the total amount of the prepared mixture is 1 Kg; the wet milling time is 15h, the degumming sintering temperature is 1300 ℃, and the heat preservation time is 0.5 h.

Comparative example 6

The comparative example refers to the preparation method of example 1, and is different from example 1 in that the mixture ratio is as follows: 82 wt% of NbC powder, 8 wt% of Ni powder and Mo₂The content of the C powder is 10 wt%, and the total amount of the prepared mixture is 1 Kg; the wet milling time is 45h, the degumming sintering temperature is 1700 ℃, and the heat preservation time is 3.5 h.

The high temperature cemented carbides prepared in example 1, example 2, example 3, comparative example 1, comparative example 2, comparative example 3, and comparative example 4 were subjected to hardness and fracture toughness tests, and the results obtained are shown in table 1 below:

TABLE 1

Numbering	Categories	hardness/HV₃₀	Fracture toughness/MPa/m²
				1	Example 1	1320	10.2
2	Example 2	1580	13.5
				3	Example 3	1650	13.8
4	Comparative example 1	1250	9.6
				5	Comparative example 2	1430	12.1
6	Comparative example 3	1510	12.5
				7	Comparative example 4	1600	12.3

In Table 1, by comparing example 1, example 2, and example 3 with comparative example 1, Mo was added to NbC-8Ni in the present invention₂The hardness and the fracture toughness of the high-temperature hard alloy after the C is improved are obviously enhanced.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. NbC-Ni-Mo₂C high-temperature hard alloy is characterized in that NbC-8Ni is taken as a base, and Mo is added₂C, mixing the following components in percentage by weight: NbC 84%, Ni 8%, Mo₂C8%; the preparation method comprises the following specific steps: s1, preparing materials according to the components in the mixture ratio, adding industrial alcohol with the water content of 5 wt% as a wet grinding medium after the materials are prepared, wherein the wet grinding time is 40 hours, and performing wet grinding to obtain slurry; s2, drying the slurry, mixing the dried powder with glue, then pressing and molding, degumming and sintering at 1600 ℃ for 3h to obtain NbC-Ni-Mo₂C high-temperature hard alloy.

2. The method of claim 1, wherein the powder of NbC in step S1 has a fisher size of 2 μm.

3. The method of claim 1, wherein the NbC-Ni-Mo₂The preparation method of the C high-temperature hard alloy is characterized in that the Fisher size of the Ni powder in the step S1 is 2 mu m.

4. The method of claim 1, wherein the NbC-Ni-Mo₂The preparation method of the C high-temperature hard alloy is characterized in that the ball-to-material ratio of the wet grinding in the step S1 is 3: 1.