CN103100977B - Preparation method of high-strength diamond grinding wheel dressing pen - Google Patents

Abstract

The invention discloses a high-strength diamond grinding wheel dressing pen and a preparation method thereof. The feature is that polycrystalline diamond and WC cemented carbide are sintered together as the tip of the trimming pen by using hot pressing sintering technology. The specific steps include: cleaning the surface of polycrystalline diamond, weighing and processing the powder according to a certain WC-based cemented carbide material formula, and brazing the trimming pen tip obtained after sintering the diamond and cemented carbide material to the pen holder to obtain high strength. diamond grinding wheel dressing pen. The grinding wheel dressing pen prepared by the invention has excellent heat resistance and strength, can meet the requirements of precise processing, prolong the service life and reduce the overall cost. The process has strong operability and good repeatability.

Description

A kind of preparation method of high-strength diamond grinding wheel dressing pen

technical field

The present invention relates to a high-strength diamond grinding wheel dressing pen and its preparation method. Specifically, it is a diamond grinding wheel dressing pen whose tip is sintered with artificial polycrystalline diamond material and WC-based hard alloy material and its preparation method. .

Background technique

For grinding wheels, the surface of the workpiece is easily stuck by abrasive particles when processing the workpiece, which affects the grinding effect. Therefore need to adopt a kind of grinding wheel dressing pen to remove the grinding debris on the surface of the grinding wheel, so that the sharpness of the grinding wheel can be recovered. Due to the grinding of the grinding wheel and the dressing pen or dressing knife when dressing the grinding wheel, the wear of the nib is relatively large, so diamond is generally used as the nib. However, due to the scarcity of natural diamond resources in our country, especially the price of high-grade diamonds is dozens of times higher than that of non-grade diamonds, most of the current grinding wheel dressing pens use artificial diamonds.

The existing diamond grinding wheel dressing pen processing method usually adopts prefabricated holes on the top of the pen holder, cuts the diamond film into the required shape and size with a laser, and pre-coats a layer of metal titanium at the same time, and then laminates the multi-layer diamond film on the Insert them together into the prefabricated hole at the top of the steel pen holder, fill them with growth solder and assemble them together to process a grinding wheel dressing pen. The processing method of welding with finger filler is that the shape and size of the tip of the trimming pen are completely determined by the shape of the prefabricated hole, and the heat resistance and strength will be limited by the welding layer between the diamond film layers.

Contents of the invention

Aiming at the deficiencies in the current application of diamond grinding wheel dressing pens, the present invention provides a high-strength diamond grinding wheel dressing pen and a preparation method thereof, which solve the problems of high price, insufficient heat resistance and insufficient strength of existing grinding wheel dressing pens. It utilizes hot pressing sintering technology, uses WC cemented carbide powder to sinter to prepare the correcting pen tip, and then brazes the sintered and pressed trimming pen tip to the trimming pen barrel. It not only maintains the high hardness and wear resistance of diamond, but also improves the overall heat resistance and strength of the trimming pen tip, and solves the problems of poor mechanical performance caused by the diamond film welding layer and internal deformation caused by cutting heat.

To achieve the above object, the invention provides a kind of preparation method of high-strength diamond wheel dressing pen, it is characterized in that comprising the following steps:

1. First, use ultrasonic cleaning technology to remove pollutants on the surface of polycrystalline diamond; weigh according to a certain WC-based cemented carbide material formula, ball mill in stages, grind and sieve after drying;

2. Put the cleaned polycrystalline diamond and the processed cemented carbide powder into the sintering mold in sequence and press them tightly;

3. Carry out sintering and molding in the sintering furnace according to the preset sintering system;

4. After taking out the nib, carry out appropriate machining, polishing, and grinding to prepare the nib;

5. Brazing the obtained nib to the pen holder.

The WC-based cemented carbide material formula above is based on WC, the adhesive is a metal with excellent high-temperature chemical stability, and an appropriate amount of nanostructure toughening agent, high-hardness material micropowder hardening agent and grain inhibitor powder are added. The matrix is WC submicron powder or nanometer powder, the mass fraction is 30-80%; the metal binder is one or more of Mo, Ni or rare earth metal, the mass fraction is 2-5%; the nano hardening agent is One or more of carbon nanotubes/wires, SiC nanowires/rods or TiC nanowires/rods, with a mass fraction of 0.5-2%; the micropowder hardening agent for high-hardness materials is one or more of high-hardness materials diamond or CBN Two kinds, the mass fraction is 10-70%; the grain inhibitor powder is one or more of TaC, VC, Cr ₃ C ₂ , NdC, TiC, the mass fraction is 0.1-2%.

The above-mentioned ball mill adopts wet ball milling technology, in which the solvent is absolute ethanol or solvent gasoline, and the grinding balls are high-hardness and wear-resistant WC balls.

The above-mentioned drying adopts the method of vacuum drying, the temperature is 100-600°C, the time is 6-48 hours, and the vacuum degree is 0-0.33Pa.

The above sintering adopts discharge plasma sintering technology or intermediate frequency induction heating sintering technology. In the discharge plasma sintering process, the initial pressure is 10-40MPa, the heating rate is 160-300℃/min, the sintering temperature is 800-1400℃, the holding time is 2-15min, and the holding pressure is 35-60MPa; the cooling rate before 750℃ is the same as The heating rate is the same, after 750°C, it is cooled with the furnace. In the medium frequency induction heating sintering process, the initial pressure is 10-40MPa, the heating rate is 200-500℃/min, the sintering temperature is 900-1500℃, the holding time is 5-20min, and the holding pressure is 30-60MPa; the cooling rate is before 750℃ Same as the heating rate, after 750°C, cool with the furnace.

The above welding method adopts high-frequency low-temperature silver-based brazing at a temperature of about 700°C.

Compared with the prior art, the present invention has the following characteristics and beneficial effects:

1. Since the present invention adopts artificial polycrystalline diamond material instead of natural diamond, the tool cost is greatly reduced.

2. The diamond material used here is a monolithic material. Compared with the existing multilayer diamond film lamination, it has the characteristics of simple processing and stable molding.

3. The diamond-tungsten carbide nib has excellent heat resistance and strength, which can meet the requirements of precise processing and prolong the service life and reduce the overall cost.

4. The preparation method has strong processability and good repeatability.

Description of drawings

Fig. 1 is a schematic sectional view of a single-point diamond grinding wheel dressing pen.

Fig. 2 is a schematic cross-sectional view of a four-point diamond grinding wheel dressing pen.

FIG. 3 is a schematic cross-sectional view of A-A in FIG. 2 .

Reference signs: 1—synthetic polycrystalline diamond, 2—WC-based hard alloy material, 3—adhesive material, 4—metal penholder.

Detailed ways

The invention provides a high-strength diamond grinding wheel dressing pen and a preparation method thereof, which comprises two parts of a dressing pen head and a pen holder. The nib is sintered and scraped by artificial polycrystalline diamond and WC cemented carbide powder. After the nib is made, it is brazed on the pen holder to obtain a trimming pen.

The present invention will be described in further detail below in conjunction with the accompanying drawings.

Referring to Fig. 1, the first embodiment is a single-point diamond grinding wheel dressing pen. The advantages are simple process structure and low process cost. It is characterized by the following steps:

1. Material treatment: First, use ultrasonic cleaning technology to remove the surface pollutants of polycrystalline diamond; according to the mass fraction of 75% submicron WC powder, 7% Mo powder, 16% diamond powder, 0.8% NdC, 1.2% SiC Weigh each reagent for nano whiskers; add the weighed powder into a high-energy stirring ball mill tank, add 10 times the mass of WC balls and 5 times the mass of absolute ethanol solvent, stir and ball mill for 36 hours; then add the weighed The hardening agent was ball milled for 80 minutes, and then the toughening agent was added for ball milling for 20 minutes; the finely ground and mixed slurry was put into a vacuum drying oven, and dried for 30 minutes at 60°C and a vacuum degree of -0.33Pa; The powder was ground with an agate mortar and then sieved through a sieve with an aperture of 1 mm.

2. Mold loading: Put the cleaned polycrystalline diamond and processed cemented carbide powder into the prefabricated sintering mold in sequence, and press them tightly.

3. Sintering: sintering in a discharge plasma sintering furnace, the initial pressure is 15MPa, the heating rate is 180°C/min, the sintering temperature is 850°C, the holding time is 3min, and the holding pressure is 50MPa; the cooling rate is the same as the heating rate before 750°C, 750°C After ℃, use furnace cooling.

4. Post-processing 1: After taking out the nib, carry out appropriate machining, polishing, and grinding to prepare the nib.

5. Brazing: The obtained nib is fixed to the metal pen holder by high-frequency and low-temperature silver-based brazing, and the temperature is controlled at about 700°C.

6. Post-processing 2: Carry out proper machining and polishing on the pruning pen.

Referring to shown in Fig. 2, 3, embodiment two is a kind of four-point type diamond grinding wheel dressing pen. It is characterized by the use of four artificial diamond pillars, which can greatly improve the service life of diamond tools. The difference from Example 1 is that the four synthetic diamond pillars in the pen head are arranged in parallel, and the wrapped WC-based cemented carbide material is sintered into a wedge shape, which improves the supporting ability of the four synthetic diamond pillars and makes the dressing pen more durable. power performance. It is characterized by the following steps:

1. Material treatment: First, use ultrasonic cleaning technology to remove the surface pollutants of polycrystalline diamond; according to the mass fraction of 77% submicron WC powder, 6% Mo powder, 16% diamond powder, 0.5% NdC, 0.5% SiC Weigh each reagent for nano whiskers; add the weighed powder into a high-energy stirring ball mill tank, add 10 times the mass of WC balls and 5 times the mass of absolute ethanol solvent, stir and ball mill for 36 hours; then add the weighed The toughening agent was ball milled for 0.5 hours, and the toughening agent was added for ball milling for 20 minutes; the finely ground and mixed slurry was put into a vacuum drying oven, and dried for 60 minutes at 40°C and a vacuum degree of -0.33Pa; The powder was ground with an agate mortar and sieved through a sieve with an aperture of 11 mm.

2. Mold loading: Put the cleaned polycrystalline diamond and processed cemented carbide powder into the prefabricated sintering mold in sequence, and press them tightly.

3. Sintering: Carry out sintering and molding in a medium frequency induction heating sintering furnace, the initial pressure is 15MPa, the heating rate is 200℃/min, the sintering temperature is 850℃, the holding time is 3min, and the holding pressure is 35MPa; the cooling rate is the same as the heating rate before 750℃, Furnace cooling is used after 750°C.

4. Post-processing 1: After taking out the nib, carry out appropriate machining, polishing, and grinding to prepare the nib;

5. Brazing: The pen head is fixed to the metal pen holder by high-frequency and low-temperature silver-based brazing technology, and the temperature is controlled at about 700°C;

6. Post-processing 2: Carry out proper machining and polishing on the pruning pen.

Claims (6)

1. a preparation method for the diamond grinding wheel dressing pen of high strength, is characterized in that comprising the following steps:

A, first ultrasonic cleaning technology is utilized to remove polycrystalline diamond surface contamination thing; Weigh by certain WC based hard alloy material formula, ball milling stage by stage, grinds after oven dry, sieves;

B, cleaned polycrystalline diamond and the cemented carbide powder handled well are put into sintering mold in order, and compress;

C, carry out sintering according to the sintering schedule preset in sintering furnace, shaping;

D, take out the nib of to carry out suitable machined and polishing, reconditioning after nib and preparing;

E, the nib obtained to be brazed on penholder.

2. the preparation method of the diamond grinding wheel dressing pen of a kind of high strength according to claim 1, it is characterized in that described WC based hard alloy material formula is for being matrix with WC, bonding agent is with the metal of stability at elevated temperature excellence, and adds appropriate nanostructured flexibilizer, the Hardening agent of high hard material micro mist and grain inhibitor powder; Matrix is WC sub-micro ground rice or nano powder, and mass fraction is 30 ~ 80%; Metal binding agent is one or more in Mo, Ni or rare earth metal, and mass fraction is 2 ~ 5%; The agent of nanometer Hardening is one or more of CNT/line, SiC nanowire/rod or TiC nano wire/rod, and mass fraction is 0.5 ~ 2%; The agent of high hard material micro mist Hardening is one or both of high hard material diamond or CBN, and mass fraction is 10 ~ 70%; Grain inhibitor powder is TaC, VC, Cr ₃c ₂, in NdC, TiC one or more, mass fraction is 0.1 ~ 2%.

3. the preparation method of the diamond grinding wheel dressing pen of a kind of high strength according to claim 1, it is characterized in that described ball milling adopts wet ball-milling technology, wherein solvent is absolute ethyl alcohol or industrial naptha, and abrading-ball is high firmly wear-resisting WC ball.

4. the preparation method of the diamond grinding wheel dressing pen of a kind of high strength according to claim 1, is characterized in that described oven dry adopts vacuum drying method, temperature 40 DEG C, 60 minutes time or temperature 60 DEG C, 30 minutes time, vacuum-0.33Pa.

5. the preparation method of the diamond grinding wheel dressing pen of a kind of high strength according to claim 1, is characterized in that described sintering adopts discharge plasma sintering technology or Frequency Induction Heating sintering technology; In discharge plasma sintering process, first pressing is 10 ~ 40MPa, heating rate 160 ~ 300 DEG C/min, and sintering temperature is 800 ~ 1400 DEG C, temperature retention time 2 ~ 15min, heat preservation pressure 35 ~ 60MPa; Cooldown rate 750 DEG C is identical with heating rate in the past, cools after 750 DEG C with stove; And in Frequency Induction Heating sintering process, first pressing is 10 ~ 40MPa, heating rate 200 ~ 500 DEG C/min, sintering temperature is 850 DEG C, temperature retention time 5 ~ 20min, heat preservation pressure 30 ~ 60MPa; Cooldown rate 750 DEG C is identical with heating rate in the past, cools after 750 DEG C with stove.

6. the preparation method of the diamond grinding wheel dressing pen of a kind of high strength according to claim 1, it is characterized in that described brazing mode adopts the soldering of high frequency low temperature money base, temperature is about 700 DEG C.