阅读说明：本技术 一种金刚石复合截齿及其低温活化液相烧结工艺 (Diamond composite cutting pick and low-temperature activation liquid phase sintering process thereof ) 是由 戴剑博 王忠宾 时佳伟 谭超 司垒 于 2021-08-06 设计创作，主要内容包括：本申请公开了一种金刚石复合截齿及其低温活化液相烧结工艺,包括截齿钢基体和金刚石-硬质合金复合齿头通过钎焊牢固连接。金刚石-硬质合金复合齿头通过低温活化液相烧结技术,将镍铬合金作为活化相添加到金刚石、碳化钨颗粒组成的胎体材料中,在900～1100℃真空氛围中烧结制备出集金刚石高耐磨性和硬质合金高抗冲击韧性于一体的齿头。低温活化液相烧结技术在较低的烧结温度下实现金刚石、镍铬合金与基体之间化学冶金结合,从根本改善三者之间的结合强度,提高基体对金刚石把持力,同时又避免了金刚石的热损伤,而且活性元素合金熔化流淌,填充基体颗粒间缝隙,获得致密烧结体,从根本上提高复合截齿的耐磨性和抗冲击性,达到高效、长久稳定截割硬岩的目的。(The application discloses a diamond composite cutting pick and a low-temperature activation liquid phase sintering process thereof. The diamond-hard alloy composite tooth head is prepared by adding nickel-chromium alloy serving as an active phase into a matrix material consisting of diamond and tungsten carbide particles through a low-temperature active liquid phase sintering technology, and sintering at 900-1100 ℃ in a vacuum atmosphere to integrate the high wear resistance of diamond and the high impact toughness of hard alloy. The low-temperature activated liquid phase sintering technology realizes chemical metallurgical bonding between the diamond, the nickel-chromium alloy and the matrix at a lower sintering temperature, so that the bonding strength among the diamond, the nickel-chromium alloy and the matrix is fundamentally improved, the holding force of the matrix on the diamond is improved, the thermal damage of the diamond is avoided, the active element alloy is melted and flows, gaps among the matrix particles are filled, a compact sintered body is obtained, the wear resistance and the impact resistance of the composite cutting pick are fundamentally improved, and the purpose of efficiently and stably cutting hard rock for a long time is achieved.)

1. The diamond composite cutting pick is characterized by comprising a cutting pick steel base body and a diamond-hard alloy composite cutting pick head which are firmly connected in a brazing mode; the raw materials of the diamond-hard alloy composite pick head comprise diamond particles, tungsten carbide particles and active element alloy powder, wherein the active element alloy powder comprises cobalt powder, nickel-chromium alloy powder and iron powder, the particle size of the active element alloy powder particles is less than or equal to 100 mu m, the cobalt powder in the active element alloy powder accounts for 5-30% of the total weight of the composite pick, the nickel-chromium alloy powder accounts for 5-20% of the total weight of the composite pick, and the iron powder accounts for 5-40% of the total weight of the composite pick; the particle size of the diamond particles is 10-500 mu m, and the mass proportion of the diamond particles in the composite cutting pick is 5% -30%; the particle size of the tungsten carbide particles is 1-500 mu m, and the tungsten carbide particles account for 30-80% of the mass of the composite cutting pick.

2. The diamond composite pick of claim 1, wherein: the diamond-hard alloy composite tooth head is prepared by adding nickel-chromium alloy serving as an active phase into a matrix material consisting of diamond, tungsten carbide powder, cobalt powder and iron powder through a low-temperature active liquid phase sintering technology, and sintering at 900-1100 ℃ in a vacuum atmosphere.

3. A low-temperature activation liquid phase sintering process for a diamond composite cutting pick is characterized by comprising the following steps:

the first step is as follows: weighing diamond particles, tungsten carbide particles, cobalt powder, nickel-chromium alloy powder and iron powder according to the weight of 5-30% of cobalt powder, 5-20% of nickel-chromium alloy powder, 5-40% of iron powder, 5-30% of diamond and 30-80% of tungsten carbide;

the second step is that: firstly, stirring and mixing diamond particles, tungsten carbide particles, cobalt powder, nickel-chromium alloy powder and iron powder in a vessel, and then fully mixing the diamond particles, the tungsten carbide particles, the cobalt powder, the nickel-chromium alloy powder and the iron powder which are stirred and mixed by using a ball mill; finally stopping the machine and sealing the mixed powder into a special vessel;

the third step: filling the uniformly mixed powder into a metal mold, cold-pressing and molding under the pressure of 2-5 GPa, and demolding to obtain a diamond composite cutting pick bit matrix;

the fourth step: sintering the demolded diamond composite pick head matrix in a vacuum furnace to prepare the diamond composite pick head;

the fifth step: and placing the diamond composite cutting pick head prepared by sintering into a cutting pick substrate for brazing to obtain the diamond composite cutting pick.

4. The low temperature activation liquid phase sintering process for a diamond composite pick according to claim 3, wherein: in the second step, the mixing balls in the ball mill are hard alloy balls, and the mixing balls with different sizes of 20mm, 10mm and 5mm in diameter are selected for matching.

5. The low temperature activation liquid phase sintering process for a diamond composite pick according to claim 4, wherein: in the second step, the rotating speed of the mixer is 40-100 revolutions per minute, and the mixing time is 1-4 hours.

6. The low temperature activation liquid phase sintering process for a diamond composite pick according to claim 3, wherein: and the cold pressing forming temperature in the third step is room temperature.

7. The low temperature activation liquid phase sintering process for a diamond composite pick according to claim 3, wherein: in the fourth step, the vacuum degree in the vacuum furnace is not less than 10^-2Pa。

8. The low temperature activation liquid phase sintering process for a diamond composite pick according to claim 3, wherein: and in the fourth step, the sintering temperature is 900-1100 ℃.

9. The low temperature activation liquid phase sintering process for a diamond composite pick according to claim 3, wherein: the sintering time in the fourth step is 30 min.

Technical Field

The invention belongs to the field of diamond composite picks, and particularly relates to a diamond composite pick and a low-temperature activation liquid phase sintering process thereof.

Background

The hard alloy cutting pick is the most widely applied rock stratum cutting executing element in the mining industry at home and abroad at present, but with the increase of the mining operation depth, hard and abrasive mineral rocks such as hard rock, coal gangue and the like are increased, the defects of poor wear resistance, low impact toughness and the like of the hard alloy cutting pick are increasingly highlighted, so that the cutting pick is easy to generate abnormal wear, short in service life and frequent in replacement, and the requirements of safe and efficient mining in the mining industry at present are difficult to meet.

At present, most of polycrystalline diamond cutting teeth and dispersive diamond cutting teeth which are researched have the problems of high manufacturing cost, easy thermal damage of diamond, easy edge breakage, poor thermal stability, gaps of sintered bodies, low breaking strength of the cutting teeth and the like, and the application requirements of rapid tunneling of a tunneling machine and efficient mining of a coal mining machine are difficult to completely meet.

Disclosure of Invention

The technical problem to be solved is as follows:

aiming at the defects of the prior art, the application provides a diamond composite cutting pick and a low-temperature activation liquid phase sintering process thereof, which solve the problems of high manufacturing cost, easy thermal damage of diamond, easy edge breakage, poor thermal stability, gaps in sintered bodies, low cutting pick breaking strength and the like; the method for developing the diamond-hard alloy composite superhard cutting tooth integrating the high wear resistance of diamond and the high impact toughness of hard alloy by adopting a low-temperature activated liquid phase sintering technology enables the diamond, the hard alloy and a brazing alloy to be chemically and metallurgically bonded, enhances the bonding strength of the diamond and a hard alloy matrix, fundamentally improves the wear resistance and the impact resistance of the composite cutting tooth, and achieves the purpose of efficiently and stably cutting hard rock for a long time.

The technical scheme is as follows:

in order to achieve the purpose, the application is realized by the following technical scheme:

a diamond composite cutting pick comprises a cutting pick steel base body and a diamond-hard alloy composite cutting pick head which are firmly connected in a brazing mode; the raw materials of the diamond-hard alloy composite pick head comprise diamond particles, tungsten carbide particles and active element alloy powder, wherein the active element alloy powder comprises cobalt powder, nickel-chromium alloy powder and iron powder, the particle size of the active element alloy powder particles is less than or equal to 100 mu m, the cobalt powder in the active element alloy powder accounts for 5-30% of the total weight of the composite pick, the nickel-chromium alloy powder accounts for 5-20% of the total weight of the composite pick, and the iron powder accounts for 5-40% of the total weight of the composite pick; the particle size of the diamond particles is 10-500 mu m, and the mass proportion of the diamond particles in the composite cutting pick is 5% -30%; the particle size of the tungsten carbide particles is 1-500 mu m, and the tungsten carbide particles account for 30-80% of the mass of the composite cutting pick.

Further, the diamond-hard alloy composite tooth head is prepared by adding nickel-chromium alloy serving as an active phase into a matrix material consisting of diamond, tungsten carbide powder, cobalt powder and iron powder through a low-temperature active liquid phase sintering technology, and sintering at 900-1100 ℃ in a vacuum atmosphere to integrate the high wear resistance of diamond and the high impact toughness of hard alloy.

The low-temperature activation liquid phase sintering process for the diamond composite cutting pick comprises the following steps:

the first step is as follows: weighing diamond particles, tungsten carbide particles, cobalt powder, nickel-chromium alloy powder and iron powder according to the weight of 5-30% of cobalt powder, 5-20% of nickel-chromium alloy powder, 5-40% of iron powder, 5-30% of diamond and 30-80% of tungsten carbide;

the second step is that: firstly, stirring and mixing diamond particles, tungsten carbide particles, cobalt powder, nickel-chromium alloy powder and iron powder in a vessel, and then fully mixing the diamond particles, the tungsten carbide particles, the cobalt powder, the nickel-chromium alloy powder and the iron powder which are stirred and mixed by using a ball mill; finally stopping the machine and sealing the mixed powder into a special vessel;

the third step: filling the uniformly mixed powder into a metal mold, cold-pressing and molding under the pressure of 2-5 GPa, and demolding to obtain a diamond composite cutting pick bit matrix;

the fourth step: sintering the demolded diamond composite pick head matrix in a vacuum furnace to prepare the diamond composite pick head;

the fifth step: and placing the diamond composite cutting pick head prepared by sintering into a cutting pick substrate for brazing to obtain the diamond composite cutting pick.

Furthermore, in the second step, the mixing balls in the ball mill are hard alloy balls, and the mixing balls with different sizes of 20mm, 10mm and 5mm in diameter are selected for matching.

Furthermore, in the second step, the rotating speed of the mixer is 40-100 revolutions per minute, and the mixing time is 1-4 hours.

Further, the cold-pressing forming temperature in the three steps is room temperature.

Further, in the fourth step, the vacuum degree in the vacuum furnace is not less than 10^-2Pa。

Further, the sintering temperature in the fourth step is 900-1100 ℃.

Further, the sintering time in the fourth step is 30 min.

Has the advantages that:

the application provides a diamond composite cutting tooth and a low-temperature activation liquid phase sintering process thereof, which have the following beneficial effects:

1. the high-strength wear-resistant diamond composite cutting pick is used for cutting hard coal rocks by equipment such as a coal mining machine, a heading machine and the like.

2. The dispersion type diamond composite cutting pick prepared by the invention takes diamond as a hardening phase and hard alloy as a matrix, combines the advantages of high hardness of the diamond and high impact toughness of the hard alloy, makes the best of the advantages and avoids the disadvantages, and forms a novel diamond superhard composite cutting pick with unique characteristics. The cutting tool is not only suitable for cutting soft and hard rock interbedded layers, medium and hard rock layers in the mining industry, but also has simple manufacturing technology and low price, and has wide application prospect in the high-consumption field of tools such as coal mining and the like.

3. Compared with the existing preparation technology of the diamond composite cutting pick, the low-temperature activation liquid phase sintering technology can realize chemical metallurgical bonding between the diamond, the nickel-chromium alloy and the matrix at a lower sintering temperature, so that the bonding strength among the diamond, the nickel-chromium alloy and the matrix is fundamentally improved, the holding force of the matrix on the diamond is improved, meanwhile, the thermal damage of the diamond is avoided, the active element alloy is melted and flows, gaps among the matrix particles are filled, a compact sintered body is obtained, the wear resistance and the shock resistance of the composite cutting pick are fundamentally improved, and the purpose of efficiently and stably cutting hard rock for a long time is achieved.

4. The diamond-hard alloy composite cutting pick prepared by low-temperature activation liquid phase sintering provided by the patent has the advantages that the abrasive resistance is improved by 5 times, the impact toughness is improved by 30%, the service life is prolonged by more than 2 times, and the cutting pick cost consumed by cutting rock in unit volume is reduced by 15% -20%.

Description of the drawings:

FIG. 1 is a schematic view of the construction of a diamond composite pick of the present invention.

Detailed Description

The following will further explain the embodiments and working procedures of the present invention by referring to examples.

Example 1:

the low-temperature activation liquid phase sintering process for the diamond composite cutting pick comprises the following steps:

the first step is as follows: weighing diamond particles, tungsten carbide particles, cobalt powder, nickel-chromium alloy powder and iron powder according to the weight percentage that the cobalt powder accounts for 5-30% of the total weight of the composite cutting pick head, the nickel-chromium alloy powder accounts for 5-20% of the total weight of the composite cutting pick head, the iron powder accounts for 5-40% of the total weight of the composite cutting pick head, the diamond accounts for 5-30% of the total weight of the composite cutting pick head, and the tungsten carbide accounts for 30-80% of the total weight of the composite cutting pick head;

the second step is that: firstly, stirring and mixing diamond particles, tungsten carbide particles, cobalt powder, nickel-chromium alloy powder and iron powder in a vessel, then fully mixing the diamond particles, the tungsten carbide particles, the cobalt powder, the nickel-chromium alloy powder and the iron powder which are stirred and mixed by using a ball mill, wherein the mixing balls are hard alloy balls, and are selected to be used in a matching way, the diameters of the mixing balls are 20mm, 10mm and 5mm, the rotating speed of a mixer is 40-100 r/min, and the mixing time is 1-4 hours; finally stopping the machine and sealing the mixed powder into a special vessel;

the third step: filling the uniformly mixed powder into a metal mold, cold-pressing and molding under the pressure of 2-5 GPa, and demolding to obtain a diamond composite cutting pick bit matrix;

the fourth step: sintering the demolded diamond composite cutting pick body in a vacuum furnace to prepare the diamond composite cutting pick, wherein the sintering temperature is 900-1100 ℃, and the vacuum degree in the furnace is not lower than 10^-2Pa, keeping the temperature for 30 min;

the fifth step: and placing the diamond composite cutting pick head prepared by sintering into a cutting pick substrate for brazing to obtain the diamond composite cutting pick.

Example 2:

the low-temperature activation liquid phase sintering process for the diamond composite cutting pick comprises the following steps:

the first step is as follows: weighing diamond particles, tungsten carbide particles, cobalt powder, nickel-chromium alloy powder and iron powder according to the weight percentage that the cobalt powder accounts for 5-30% of the total weight of the composite cutting pick head, the nickel-chromium alloy powder accounts for 5-20% of the total weight of the composite cutting pick head, the iron powder accounts for 5-40% of the total weight of the composite cutting pick head, the diamond accounts for 5-30% of the total weight of the composite cutting pick head, and the tungsten carbide accounts for 30-80% of the total weight of the composite cutting pick head;

the second step is that: firstly, stirring and mixing diamond particles, tungsten carbide particles, cobalt powder, nickel-chromium alloy powder and iron powder in a vessel, then fully mixing the diamond particles, the tungsten carbide particles, the cobalt powder, the nickel-chromium alloy powder and the iron powder which are stirred and mixed by using a ball mill, wherein the mixing balls are hard alloy balls, and are selected to be used in a matching way, the diameters of the mixing balls are 20mm, 10mm and 5mm, the rotating speed of a mixer is 40 revolutions per minute, and the mixing time is 1 hour; finally stopping the machine and sealing the mixed powder into a special vessel;

the third step: filling the uniformly mixed powder into a metal mold, cold-pressing and molding under the pressure of 2-5 GPa, and demolding to obtain a diamond composite cutting pick bit matrix;

the fourth step: sintering the demolded diamond composite cutting pick body in a vacuum furnace to prepare the diamond composite cutting pick, wherein the sintering temperature is 900 ℃, and the vacuum degree in the furnace is not lower than 10^-2Pa, keeping the temperature for 30 min;

the fifth step: and placing the diamond composite cutting pick head prepared by sintering into a cutting pick substrate for brazing to obtain the diamond composite cutting pick.

Example 3:

the low-temperature activation liquid phase sintering process for the diamond composite cutting pick comprises the following steps:

the first step is as follows: weighing diamond particles, tungsten carbide particles, cobalt powder, nickel-chromium alloy powder and iron powder according to the weight percentage that the cobalt powder accounts for 5-30% of the total weight of the composite cutting pick head, the nickel-chromium alloy powder accounts for 5-20% of the total weight of the composite cutting pick head, the iron powder accounts for 5-40% of the total weight of the composite cutting pick head, the diamond accounts for 5-30% of the total weight of the composite cutting pick head, and the tungsten carbide accounts for 30-80% of the total weight of the composite cutting pick head;

the second step is that: firstly, stirring and mixing diamond particles, tungsten carbide particles, cobalt powder, nickel-chromium alloy powder and iron powder in a vessel, then fully mixing the diamond particles, the tungsten carbide particles, the cobalt powder, the nickel-chromium alloy powder and the iron powder which are stirred and mixed by using a ball mill, wherein the mixing balls are hard alloy balls, and are selected to be used in a matching way, the diameters of the mixing balls are 20mm, 10mm and 5mm, the rotating speed of a mixer is 100 revolutions per minute, and the mixing time is 4 hours; finally stopping the machine and sealing the mixed powder into a special vessel;

the third step: filling the uniformly mixed powder into a metal mold, cold-pressing and molding under the pressure of 2-5 GPa, and demolding to obtain a diamond composite cutting pick bit matrix;

the fourth step: sintering the demolded diamond composite cutting pick body in a vacuum furnace to prepare the diamond composite cutting pick, wherein the sintering temperature is 1100 ℃, and the vacuum degree in the furnace is not lower than 10^-2Pa, keeping the temperature for 30 min;

the fifth step: and placing the diamond composite cutting pick head prepared by sintering into a cutting pick substrate for brazing to obtain the diamond composite cutting pick.

The result shows that the brazing filler metal can reduce the sintering welding temperature, the brazing filler metal is melted uniformly, a thin layer of continuous flaky carbide is formed on the surface of the diamond abrasive particles, the brazing filler metal is moderate in hardness, the holding strength on diamond is high, and the thermal damage to the diamond is small.

Finally, the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and other modifications or equivalent substitutions made by the technical solutions of the present invention by the person skilled in the art shall be covered by the scope of the claims of the present invention without departing from the spirit and scope of the technical solutions of the present invention.