阅读说明：本技术 一种用于装饰镀膜的碳化钨靶材及其制备方法 (Tungsten carbide target material for decorative coating and preparation method thereof ) 是由 姚力军 潘杰 边逸军 王学泽 杨慧珍 于 2021-09-08 设计创作，主要内容包括：本发明提供了一种用于装饰镀膜的碳化钨靶材及其制备方法,所述制备方法包括以下步骤：(1)筛分纯度≥99.98％的碳化钨原料,得到碳化钨粉末；(2)将步骤(1)所得碳化钨粉末进行烧结温度为1800-1900℃,压制压力为35-45MPa的真空热压烧结处理,得到碳化钨靶坯；(3)将步骤(2)所得碳化钨靶坯进行机加工,得到碳化钨靶材；其中,步骤(2)所述真空热压烧结处理包括顺次进行的保温处理和保温保压处理,且所述保温处理的升温过程分为至少3个升温阶段。本发明提供的制备方法精简了工艺流程的同时提升了碳化钨靶材及镀膜质量。(The invention provides a tungsten carbide target material for decorative coating and a preparation method thereof, wherein the preparation method comprises the following steps: (1) screening a tungsten carbide raw material with the purity of more than or equal to 99.98 percent to obtain tungsten carbide powder; (2) carrying out vacuum hot-pressing sintering treatment on the tungsten carbide powder obtained in the step (1) at the sintering temperature of 1800-1900 ℃ and the pressing pressure of 35-45MPa to obtain a tungsten carbide target blank; (3) machining the tungsten carbide target blank obtained in the step (2) to obtain a tungsten carbide target; and (3) performing vacuum hot-pressing sintering treatment in the step (2) by sequentially performing heat preservation treatment and heat preservation and pressure maintaining treatment, wherein the temperature rise process of the heat preservation treatment is divided into at least 3 temperature rise stages. The preparation method provided by the invention simplifies the process flow and improves the tungsten carbide target material and the coating quality.)

1. The preparation method of the tungsten carbide target material for decorative coating is characterized by comprising the following steps:

(1) screening a tungsten carbide raw material with the purity of more than or equal to 99.98 percent to obtain tungsten carbide powder;

(2) carrying out vacuum hot-pressing sintering treatment on the tungsten carbide powder obtained in the step (1) at the sintering temperature of 1800-1900 ℃ and the pressing pressure of 35-45MPa to obtain a tungsten carbide target blank;

(3) machining the tungsten carbide target blank obtained in the step (2) to obtain a tungsten carbide target;

and (3) performing vacuum hot-pressing sintering treatment in the step (2) by sequentially performing heat preservation treatment and heat preservation and pressure maintaining treatment, wherein the temperature rise process of the heat preservation treatment is divided into at least 3 temperature rise stages.

2. The method according to claim 1, wherein the average particle diameter of the tungsten carbide powder in the step (1) is 5 μm or less.

3. The production method according to claim 1 or 2, wherein the vacuum hot pressing sintering process of step (2) comprises sequentially performing mold filling, vacuum pumping, temperature raising, heat preservation, pressurization, heat preservation and pressure maintaining, pressure releasing and cooling.

4. The preparation method according to claim 3, wherein the mold filling body is: filling tungsten carbide powder into a graphite die and compacting, and ensuring that the flatness is less than or equal to 0.5mm after die filling;

preferably, the vacuum pumping is specifically: and putting the graphite mold into a vacuum sintering furnace, and vacuumizing until the absolute pressure in the furnace is less than or equal to 100 Pa.

5. The production method according to claim 3 or 4, wherein the temperature raising process is divided into 3 temperature raising stages, namely, a first temperature raising stage, a second temperature raising stage and a third temperature raising stage which are sequentially performed;

preferably, the heating rate of the first heating stage is 8-12 ℃/min;

preferably, the target temperature of the first temperature-raising stage is 900-1100 ℃;

preferably, the temperature rise rate of the second temperature rise stage is 4-6 ℃/min;

preferably, the target temperature of the second temperature-raising stage is 1450-;

preferably, the temperature rise rate of the third temperature rise stage is 2-4 ℃/min;

preferably, the target temperature of the third temperature-raising stage is 1800-1900 ℃;

preferably, the time of the heat preservation treatment is 80-100 min.

6. The production method according to any one of claims 3 to 5, wherein the rate of pressurization is 0.4 to 0.6 MPa/min;

preferably, the target pressure of the pressurization is 35 to 45 MPa;

preferably, the time of the heat preservation and pressure maintaining treatment is 80-100 min.

7. The preparation method according to any one of claims 3 to 6, wherein the pressure removal is specifically: filling nitrogen and/or argon into the vacuum sintering furnace until the absolute pressure in the furnace is 0.02-0.04 MPa;

preferably, the cooling is specifically: and taking out the mold when the mold is cooled to the temperature of less than or equal to 200 ℃ along with the furnace, and cooling to room temperature.

8. The method according to any one of claims 1 to 7, wherein the machining in step (3) comprises grinding, cutting, finishing, surface treatment, cleaning, drying and packaging which are performed in sequence;

preferably, the grinding is carried out on a plane grinder, and the specification of the grinding wheel of the adopted grinder is 60-100 meshes;

preferably, the flatness achieved by the grinding is less than or equal to 0.05 mm;

preferably, the blade setting amount of each step of grinding is less than or equal to 0.05 mm;

preferably, the cutting is performed on a wire cutting machine;

preferably, the finish machining is carried out on a milling machine, and the specification of the adopted cylindrical grinding head is 300-500 meshes;

preferably, the feed amount of each step of finish machining is less than or equal to 0.05 mm;

preferably, the surface treatment includes grinding and polishing performed in sequence.

9. The method of any one of claims 1 to 8, comprising the steps of:

(1) screening tungsten carbide raw materials with the purity of more than or equal to 99.98 percent to obtain tungsten carbide powder with the average grain diameter of less than or equal to 5 mu m;

(2) carrying out vacuum hot-pressing sintering treatment on the tungsten carbide powder obtained in the step (1) to obtain a tungsten carbide target blank; the vacuum hot-pressing sintering treatment specifically comprises the following steps:

(A) die filling: filling tungsten carbide powder into a graphite die and compacting, and ensuring that the flatness is less than or equal to 0.5mm after die filling;

(B) vacuumizing: putting the graphite mould into a vacuum sintering furnace, and vacuumizing until the absolute pressure in the furnace is less than or equal to 100 Pa;

(C) and (3) heating: heating to 900-;

(D) and (3) heat preservation treatment: preserving the heat for 80-100min to fully heat the green body;

(E) pressurizing: pressurizing to 35-45MPa at the rate of 0.4-0.6 MPa/min;

(F) and (3) heat preservation and pressure maintaining treatment: keeping the temperature and the pressure for 80-100 min;

(G) pressure removal: filling nitrogen and/or argon into the vacuum sintering furnace until the absolute pressure in the furnace is 0.02-0.04 MPa;

(H) and (3) cooling: cooling the mold along with the furnace to a temperature of less than or equal to 200 ℃, taking out the mold and airing to room temperature;

(3) machining the tungsten carbide target blank obtained in the step (2) to obtain a tungsten carbide target; the machining comprises the steps of grinding, cutting, finish machining, surface treatment, cleaning, drying and packaging which are sequentially carried out; the grinding is carried out on a plane grinder, and the specification of the grinding wheel of the adopted grinder is 60-100 meshes; the flatness achieved by the grinding is less than or equal to 0.05mm, and the cutting amount in each step is less than or equal to 0.05 mm; the cutting is carried out on a wire cutting machine; the fine machining is carried out on a milling machine, the specification of the adopted cylindrical grinding head is 300 plus 500 meshes, and the amount of cutting in each step is less than or equal to 0.05 mm; the surface treatment comprises grinding and polishing which are sequentially carried out.

10. A tungsten carbide target material prepared by the preparation method according to any one of claims 1 to 9.

Technical Field

The invention belongs to the technical field of sputtering targets, relates to a tungsten carbide target, and particularly relates to a tungsten carbide target for decorative coating and a preparation method thereof.

Background

In the production process of automobile parts, technicians often plate a layer of tungsten carbide on the surface of the parts to serve as a wear-resistant layer in order to improve the wear resistance and the aesthetic property of the surfaces of the parts. Most of the current coatings are deposited by physical vapor deposition, which requires tungsten carbide targets with larger dimensions. However, the tungsten carbide target has high molding temperature, high quality, difficult processing and high performance requirement of the target, so that the production process of the tungsten carbide target is complicated and unstable, and the existing target cannot meet the high requirement of the industry on the quality of the target.

CN 103567440A discloses a preparation method of a tungsten carbide target material for coating a petroleum exploration drill bit, which comprises the following steps: (1) filling tungsten carbide powder with the purity of 99.999 percent into a graphite die, and carrying out cold pressing; (2) placing a graphite die filled with tungsten carbide powder formed by pre-cold pressing into a discharge plasma furnace, and heating to 1600-2200 ℃ under protective atmosphere; (3) performing rapid discharge in the discharge plasma furnace to form short circuit, and instantly sintering the tungsten carbide powder to form a tungsten carbide target blank with fine and uniform grains; (4) and cooling the blank along with the furnace, taking out the blank, and machining according to requirements to obtain the tungsten carbide target material. The tungsten carbide target material prepared by the method has uniform and fine grains, can obviously improve the strength and the wear resistance of the petroleum exploration drill bit, and prolongs the service life of the petroleum exploration drill bit. However, the rapid discharge in the method is not easy to control and has high danger coefficient, and a certain degree of anisotropy exists in the preparation of large-size tungsten carbide targets, so that a larger improvement space still exists.

CN 110171975A discloses a large-size high-density binderless tungsten carbide target material and a preparation method thereof, which comprises the following steps: s1, material preparation: weighing the raw materials according to the mass fraction ratio for later use; s2, ball milling and screening: performing ball milling treatment on the raw materials weighed in the step S1 to obtain slurry, drying the uniformly mixed slurry, and finally performing screening treatment to obtain mixed powder with uniform particle size; s3, sintering treatment: putting the mixed powder obtained in the step S2 into a die, placing the die in a sintering furnace for sintering treatment, simultaneously applying dynamic oscillation pressure, cooling and demoulding to obtain a tungsten carbide target blank; s4, post-processing: and (5) cutting and surface processing the tungsten carbide target blank obtained in the step (S3) to obtain the tungsten carbide target. According to the invention, a certain amount of free carbon is introduced into the pure tungsten carbide powder, so that the hardness of the tungsten carbide film can be reduced to a certain extent, the conditions of high-pressure oscillation auxiliary sintering are not easy to control, and the production process is relatively complex.

Therefore, how to provide the tungsten carbide target material for decorative coating and the preparation method thereof, which simplify the process flow and improve the tungsten carbide target material and the coating quality becomes a problem to be solved by technical personnel in the field at present.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide the tungsten carbide target material for decorative coating and the preparation method thereof, wherein the preparation method simplifies the process flow and improves the tungsten carbide target material and the coating quality.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the present invention provides a method for preparing a tungsten carbide target material for decorative coating, the method comprising the following steps:

(1) screening a tungsten carbide raw material with the purity of more than or equal to 99.98 percent to obtain tungsten carbide powder;

(2) carrying out vacuum hot-pressing sintering treatment on the tungsten carbide powder obtained in the step (1) at the sintering temperature of 1800-1900 ℃ and the pressing pressure of 35-45MPa to obtain a tungsten carbide target blank;

(3) machining the tungsten carbide target blank obtained in the step (2) to obtain a tungsten carbide target;

and (3) performing vacuum hot-pressing sintering treatment in the step (2) by sequentially performing heat preservation treatment and heat preservation and pressure maintaining treatment, wherein the temperature rise process of the heat preservation treatment is divided into at least 3 temperature rise stages.

According to the invention, the sintering temperature and the pressing pressure of the vacuum hot-pressing sintering treatment are reasonably controlled, the density of the obtained tungsten carbide target is improved to more than 99%, the purity is up to more than 99.98%, meanwhile, the heat preservation treatment and the heat preservation and pressure maintaining treatment are carried out firstly, and the temperature rise process is divided into at least 3 temperature rise stages, so that the uniformity and the sputtering stability of crystal grains in the target are further improved, the microstructure is uniform and has no pores, and the wear resistance of the decorative coating film is obviously improved.

In the present invention, the purity of the tungsten carbide raw material in the step (1) is not less than 99.98%, for example, 99.98%, 99.99% or 99.999%, but the purity is not limited to the recited values, and other values not recited in the above range are also applicable.

In the present invention, the sintering temperature in step (2) is 1800-1900 ℃, and may be 1800 ℃, 1810 ℃, 1820 ℃, 1830 ℃, 1840 ℃, 1850 ℃, 1860 ℃, 1870 ℃, 1880 ℃, 1890 ℃ or 1900 ℃, for example, but not limited to the values listed, and other values not listed in the range of the values are also applicable.

In the present invention, the pressing pressure in the step (2) is 35 to 45MPa, and may be 35MPa, 36MPa, 37MPa, 38MPa, 39MPa, 40MPa, 41MPa, 42MPa, 43MPa, 44MPa or 45MPa, for example, but it is not limited to the above-mentioned values, and other values not mentioned in the above-mentioned range are also applicable.

Preferably, the tungsten carbide powder of step (1) has an average particle size of 5 μm or less, and may be, for example, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm or 5 μm, but is not limited to the values listed, and other values not listed in the numerical range are also applicable.

Preferably, the vacuum hot-pressing sintering treatment in the step (2) includes sequentially performing mold filling, vacuum pumping, temperature raising, heat preservation treatment, pressurization, heat preservation and pressure maintaining treatment, pressure removal and cooling.

Preferably, the die filling specifically comprises: the tungsten carbide powder is charged into a graphite mold and compacted to ensure flatness of 0.5mm or less after mold filling, and may be, for example, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm or 0.5mm, but is not limited to the values listed, and other values not listed in the range of values are also applicable.

Preferably, the vacuum pumping is specifically: the graphite mold is placed in a vacuum sintering furnace and is evacuated to an absolute pressure of 100Pa or less in the furnace, and may be, for example, 10Pa, 20Pa, 30Pa, 40Pa, 50Pa, 60Pa, 70Pa, 80Pa, 90Pa or 100Pa, but the values are not limited to the values listed above, and other values not listed above within the range of values are also applicable.

Preferably, the temperature raising process is divided into 3 temperature raising stages, namely a first temperature raising stage, a second temperature raising stage and a third temperature raising stage which are sequentially performed.

Preferably, the temperature increase rate of the first temperature increase stage is 8-12 ℃/min, for example, 8 ℃/min, 8.5 ℃/min, 9 ℃/min, 9.5 ℃/min, 10 ℃/min, 10.5 ℃/min, 11 ℃/min, 11.5 ℃/min, or 12 ℃/min, but is not limited to the recited values, and other values not recited within the range of values are also applicable.

Preferably, the target temperature of the first temperature raising stage is 900-.

Preferably, the temperature increase rate of the second temperature increase stage is 4-6 ℃/min, and may be, for example, 4 ℃/min, 4.2 ℃/min, 4.4 ℃/min, 4.6 ℃/min, 4.8 ℃/min, 5 ℃/min, 5.2 ℃/min, 5.4 ℃/min, 5.6 ℃/min, 5.8 ℃/min, or 6 ℃/min, but is not limited to the recited values, and other values not recited within the range of values are also applicable.

Preferably, the target temperature of the second temperature raising stage is 1450-.

Preferably, the temperature increase rate of the third temperature increase stage is 2-4 ℃/min, and may be, for example, 2 ℃/min, 2.2 ℃/min, 2.4 ℃/min, 2.6 ℃/min, 2.8 ℃/min, 3 ℃/min, 3.2 ℃/min, 3.4 ℃/min, 3.6 ℃/min, 3.8 ℃/min, or 4 ℃/min, but is not limited to the recited values, and other values not recited within the range of values are also applicable.

Preferably, the target temperature of the third temperature raising stage is 1800-1900 ℃, and may be, for example, 1800 ℃, 1810 ℃, 1820 ℃, 1830 ℃, 1840 ℃, 1850 ℃, 1860 ℃, 1870 ℃, 1880 ℃, 1890 ℃ or 1900 ℃, but is not limited to the recited values, and other values not recited within this range are equally applicable.

Preferably, the time of the heat-preservation treatment is 80-100min, for example, 80min, 82min, 84min, 86min, 88min, 90min, 92min, 94min, 96min, 98min or 100min, but is not limited to the recited values, and other values not recited in the range of the values are also applicable.

Preferably, the rate of pressurization is from 0.4 to 0.6MPa/min, and may be, for example, 0.4MPa/min, 0.42MPa/min, 0.44MPa/min, 0.46MPa/min, 0.48MPa/min, 0.5MPa/min, 0.52MPa/min, 0.54MPa/min, 0.56MPa/min, 0.58MPa/min or 0.6MPa/min, but is not limited to the values recited, and other values not recited within the range of values are equally applicable.

Preferably, the target pressure for pressurization is 35 to 45MPa, and may be, for example, 35MPa, 36MPa, 37MPa, 38MPa, 39MPa, 40MPa, 41MPa, 42MPa, 43MPa, 44MPa or 45MPa, but is not limited to the recited values, and other values not recited in the numerical range are also applicable.

Preferably, the time of the heat-preserving and pressure-maintaining treatment is 80-100min, for example, 80min, 82min, 84min, 86min, 88min, 90min, 92min, 94min, 96min, 98min or 100min, but is not limited to the enumerated values, and other unrecited values in the numerical range are also applicable.

Preferably, the pressure removing is specifically as follows: the nitrogen gas and/or argon gas is introduced into the vacuum sintering furnace to an absolute pressure of 0.02 to 0.04MPa, for example, 0.02MPa, 0.022MPa, 0.024MPa, 0.026MPa, 0.028MPa, 0.03MPa, 0.032MPa, 0.034MPa, 0.036MPa, 0.038MPa or 0.04MPa, but the values are not limited to the values mentioned above, and other values not mentioned above are also applicable within the range.

Preferably, the cooling is specifically: when the mold is cooled to a temperature of 200 ℃ or less, the mold is removed and cooled to room temperature, which may be, for example, 50 ℃, 60 ℃, 80 ℃, 100 ℃, 120 ℃, 140 ℃, 160 ℃, 180 ℃ or 200 ℃, but is not limited to the values listed, and other values not listed within the range of values are also applicable.

Preferably, the machining in step (3) comprises grinding, cutting, finishing, surface treatment, cleaning, drying and packaging which are sequentially carried out.

Preferably, the grinding is performed on a flat grinder, and the grinding wheel of the grinder is 60-100 mesh, such as 60 mesh, 65 mesh, 70 mesh, 75 mesh, 80 mesh, 85 mesh, 90 mesh, 95 mesh or 100 mesh, but not limited to the recited values, and other values not recited in the range of values are also applicable.

Preferably, the flatness achieved by the smoothing is 0.05mm or less, and may be, for example, 0.005mm, 0.01mm, 0.015mm, 0.02mm, 0.025mm, 0.03mm, 0.035mm, 0.04mm, 0.045mm or 0.05mm, but is not limited to the values listed, and other values not listed in this range of values are equally suitable.

Preferably, the amount of cut per step of the smoothing is 0.05mm or less, for example 0.005mm, 0.01mm, 0.015mm, 0.02mm, 0.025mm, 0.03mm, 0.035mm, 0.04mm, 0.045mm or 0.05mm, but is not limited to the values listed, and other values not listed in this range of values are equally suitable.

Preferably, the cutting is performed on a wire cutter.

Preferably, the finishing is performed on a milling machine, and the size of the cylindrical grinding head used is 300-500 meshes, such as 300 meshes, 320 meshes, 340 meshes, 360 meshes, 380 meshes, 400 meshes, 420 meshes, 440 meshes, 460 meshes, 480 meshes or 500 meshes, but the method is not limited to the enumerated values, and other non-enumerated values in the numerical range are also applicable.

Preferably, the finishing is carried out with a depth of cut of 0.05mm or less per step, for example 0.005mm, 0.01mm, 0.015mm, 0.02mm, 0.025mm, 0.03mm, 0.035mm, 0.04mm, 0.045mm or 0.05mm, but not limited to the values listed, and other values not listed in this range of values are equally suitable.

Preferably, the surface treatment includes grinding and polishing performed in sequence.

According to the invention, the tungsten carbide target blank is processed into the tungsten carbide target material with a smooth surface and no corner collapse and burr through machining with specific flow and parameter requirements, so that the appearance requirement of magnetron sputtering coating on the target material is met.

As a preferred technical solution of the first aspect of the present invention, the preparation method comprises the steps of:

(1) screening tungsten carbide raw materials with the purity of more than or equal to 99.98 percent to obtain tungsten carbide powder with the average grain diameter of less than or equal to 5 mu m;

(2) carrying out vacuum hot-pressing sintering treatment on the tungsten carbide powder obtained in the step (1) to obtain a tungsten carbide target blank; the vacuum hot-pressing sintering treatment specifically comprises the following steps:

(A) die filling: filling tungsten carbide powder into a graphite die and compacting, and ensuring that the flatness is less than or equal to 0.5mm after die filling;

(B) vacuumizing: putting the graphite mould into a vacuum sintering furnace, and vacuumizing until the absolute pressure in the furnace is less than or equal to 100 Pa;

(C) and (3) heating: heating to 900-;

(D) and (3) heat preservation treatment: preserving the heat for 80-100min to fully heat the green body;

(E) pressurizing: pressurizing to 35-45MPa at the rate of 0.4-0.6 MPa/min;

(F) and (3) heat preservation and pressure maintaining treatment: keeping the temperature and the pressure for 80-100 min;

(G) pressure removal: filling nitrogen and/or argon into the vacuum sintering furnace until the absolute pressure in the furnace is 0.02-0.04 MPa;

(H) and (3) cooling: cooling the mold along with the furnace to a temperature of less than or equal to 200 ℃, taking out the mold and airing to room temperature;

(3) machining the tungsten carbide target blank obtained in the step (2) to obtain a tungsten carbide target; the machining comprises the steps of grinding, cutting, finish machining, surface treatment, cleaning, drying and packaging which are sequentially carried out; the grinding is carried out on a plane grinder, and the specification of the grinding wheel of the adopted grinder is 60-100 meshes; the flatness achieved by the grinding is less than or equal to 0.05mm, and the cutting amount in each step is less than or equal to 0.05 mm; the cutting is carried out on a wire cutting machine; the fine machining is carried out on a milling machine, the specification of the adopted cylindrical grinding head is 300 plus 500 meshes, and the amount of cutting in each step is less than or equal to 0.05 mm; the surface treatment comprises grinding and polishing which are sequentially carried out.

In a second aspect, the present invention provides a tungsten carbide target material prepared by the preparation method according to the first aspect.

Compared with the prior art, the invention has the beneficial effects that:

according to the invention, the sintering temperature and the pressing pressure of the vacuum hot-pressing sintering treatment are reasonably controlled, the density of the obtained tungsten carbide target is improved to more than 99%, the purity is up to more than 99.98%, meanwhile, the heat preservation treatment and the heat preservation and pressure maintaining treatment are carried out firstly, and the temperature rise process is divided into at least 3 temperature rise stages, so that the uniformity and the sputtering stability of crystal grains in the target are further improved, the microstructure is uniform and has no pores, and the wear resistance of the decorative coating film is obviously improved.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments.

Example 1

The embodiment provides a tungsten carbide target material for decorative coating and a preparation method thereof, wherein the preparation method comprises the following steps:

(1) screening tungsten carbide raw materials with the purity of more than or equal to 99.99 percent to obtain tungsten carbide powder with the average grain diameter of 3 mu m;

(2) carrying out vacuum hot-pressing sintering treatment on the tungsten carbide powder obtained in the step (1) to obtain a tungsten carbide target blank; the vacuum hot-pressing sintering treatment specifically comprises the following steps:

(A) die filling: filling tungsten carbide powder into a graphite die and compacting, and ensuring that the flatness is 0.3 +/-0.1 mm after die filling;

(B) vacuumizing: putting the graphite mould into a vacuum sintering furnace, and vacuumizing until the absolute pressure in the furnace is 80 Pa;

(C) and (3) heating: heating to 1000 deg.C at a rate of 10 deg.C/min, heating to 1500 deg.C at a rate of 5 deg.C/min, and heating to 1850 deg.C at a rate of 3 deg.C/min;

(D) and (3) heat preservation treatment: preserving the temperature for 90min to fully heat the green body;

(E) pressurizing: pressurizing to 40MPa at the rate of 0.5 MPa/min;

(F) and (3) heat preservation and pressure maintaining treatment: keeping the temperature and the pressure for 90 min;

(G) pressure removal: filling argon into the vacuum sintering furnace until the absolute pressure in the furnace is 0.03 MPa;

(H) and (3) cooling: cooling the mold with the furnace to 150 ℃, taking out the mold and airing to room temperature;

(3) machining the tungsten carbide target blank obtained in the step (2) to obtain a tungsten carbide target; the machining comprises the steps of grinding, cutting, finish machining, surface treatment, cleaning, drying and packaging which are sequentially carried out; the grinding is carried out on a plane grinding machine, and the specification of the grinding wheel of the adopted grinding machine is 80 meshes; the flatness achieved by the grinding is 0.03 +/-0.01 mm, and the cutting amount in each step is 0.03 mm; the cutting is carried out on a wire cutting machine; the fine machining is carried out on a milling machine, the specification of an adopted cylindrical grinding head is 400 meshes, and the amount of each step of cutter is 0.03 mm; the surface treatment comprises grinding and polishing which are sequentially carried out.

Example 2

The embodiment provides a tungsten carbide target material for decorative coating and a preparation method thereof, wherein the preparation method comprises the following steps:

(1) screening tungsten carbide raw materials with the purity of more than or equal to 99.98 percent to obtain tungsten carbide powder with the average grain diameter of 4 mu m;

(2) carrying out vacuum hot-pressing sintering treatment on the tungsten carbide powder obtained in the step (1) to obtain a tungsten carbide target blank; the vacuum hot-pressing sintering treatment specifically comprises the following steps:

(A) die filling: filling tungsten carbide powder into a graphite die and compacting, and ensuring that the flatness is 0.4 +/-0.1 mm after die filling;

(B) vacuumizing: putting the graphite mould into a vacuum sintering furnace, and vacuumizing until the absolute pressure in the furnace is 90 Pa;

(C) and (3) heating: heating to 900 deg.C at a rate of 8 deg.C/min, heating to 1450 deg.C at a rate of 4 deg.C/min, and heating to 1800 deg.C at a rate of 2 deg.C/min;

(D) and (3) heat preservation treatment: preserving the heat for 80min to fully heat the green body;

(E) pressurizing: pressurizing to 35MPa at the rate of 0.4 MPa/min;

(F) and (3) heat preservation and pressure maintaining treatment: keeping the temperature and the pressure for 80 min;

(G) pressure removal: filling nitrogen into the vacuum sintering furnace until the absolute pressure in the furnace is 0.02 MPa;

(H) and (3) cooling: cooling the mold along with the furnace to 100 ℃, taking out the mold and airing to room temperature;

(3) machining the tungsten carbide target blank obtained in the step (2) to obtain a tungsten carbide target; the machining comprises the steps of grinding, cutting, finish machining, surface treatment, cleaning, drying and packaging which are sequentially carried out; the grinding is carried out on a plane grinding machine, and the specification of the grinding wheel of the adopted grinding machine is 60 meshes; the flatness achieved by the grinding is 0.04 +/-0.01 mm, and the cutting amount in each step is 0.04 mm; the cutting is carried out on a wire cutting machine; the fine machining is carried out on a milling machine, the specification of an adopted cylindrical grinding head is 300 meshes, and the amount of each step of cutter is 0.04 mm; the surface treatment comprises grinding and polishing which are sequentially carried out.

Example 3

The embodiment provides a tungsten carbide target material for decorative coating and a preparation method thereof, wherein the preparation method comprises the following steps:

(1) screening tungsten carbide raw materials with the purity of more than or equal to 99.98 percent to obtain tungsten carbide powder with the average grain diameter of 5 mu m;

(2) carrying out vacuum hot-pressing sintering treatment on the tungsten carbide powder obtained in the step (1) to obtain a tungsten carbide target blank; the vacuum hot-pressing sintering treatment specifically comprises the following steps:

(A) die filling: filling tungsten carbide powder into a graphite die and compacting, and ensuring that the flatness is 0.4 +/-0.1 mm after die filling;

(B) vacuumizing: putting the graphite mould into a vacuum sintering furnace, and vacuumizing until the absolute pressure in the furnace is 100 Pa;

(C) and (3) heating: heating to 1100 deg.C at a rate of 12 deg.C/min, heating to 1550 deg.C at a rate of 6 deg.C/min, and heating to 1900 deg.C at a rate of 4 deg.C/min;

(D) and (3) heat preservation treatment: preserving the heat for 100min to fully heat the green body;

(E) pressurizing: pressurizing to 45MPa at the rate of 0.6 MPa/min;

(F) and (3) heat preservation and pressure maintaining treatment: keeping the temperature and the pressure for 100 min;

(G) pressure removal: filling argon into the vacuum sintering furnace until the absolute pressure in the furnace is 0.04 MPa;

(H) and (3) cooling: cooling the mold with the furnace to 200 ℃, taking out the mold and airing to room temperature;

(3) machining the tungsten carbide target blank obtained in the step (2) to obtain a tungsten carbide target; the machining comprises the steps of grinding, cutting, finish machining, surface treatment, cleaning, drying and packaging which are sequentially carried out; the grinding is carried out on a plane grinding machine, and the specification of the grinding wheel of the adopted grinding machine is 100 meshes; the flatness achieved by the grinding is 0.04 +/-0.01 mm, and the cutting amount in each step is 0.05 mm; the cutting is carried out on a wire cutting machine; the fine machining is carried out on a milling machine, the specification of an adopted cylindrical grinding head is 500 meshes, and the feed amount per step is 0.05 mm; the surface treatment comprises grinding and polishing which are sequentially carried out.

Example 4

The present embodiment provides a tungsten carbide target for decorative coating and a preparation method thereof, wherein the preparation method is the same as that of embodiment 1 except that the time for heat preservation in step (2) is changed to 70min, and thus, the details are not repeated herein.

Example 5

The present embodiment provides a tungsten carbide target for decorative coating and a preparation method thereof, wherein the preparation method is the same as that in embodiment 1 except that the time for heat and pressure maintaining in step (2) is changed to 70min, and thus, the details are not repeated herein.

Comparative example 1

The preparation method is the same as that in the example 1 except that the final target temperature of the temperature rise in the step (2) is changed to 1750 ℃, and the other conditions are the same, so that the details are not repeated herein.

Comparative example 2

The comparison example provides a tungsten carbide target material for decorative coating and a preparation method thereof, and the preparation method is the same as the example 1 except that the final target temperature of temperature rise in the step (2) is 1950 ℃, so that the detailed description is omitted.

Comparative example 3

The comparative example provides a tungsten carbide target material for decorative coating and a preparation method thereof, and the preparation method is the same as that of example 1 except that the final pressing pressure of pressurization in step (2) is changed to 30MPa, so that the details are not repeated.

Comparative example 4

The comparative example provides a tungsten carbide target material for decorative coating and a preparation method thereof, and the preparation method is the same as that of example 1 except that the final pressing pressure of pressurization in step (2) is changed to 50MPa, so that the details are not repeated.

Comparative example 5

The comparative example provides a tungsten carbide target material for decorative coating and a preparation method thereof, wherein the preparation method changes the temperature rise process in the step (2) into the following steps: the temperature is raised to 1500 ℃ at a rate of 12 ℃/min, then to 1850 ℃ at a rate of 5 ℃/min, and the rest conditions are the same as those in example 1, and thus the details are not repeated herein.

Comparative example 6

The comparative example provides a tungsten carbide target material for decorative coating and a preparation method thereof, and the preparation method comprises the following steps:

(1) screening tungsten carbide raw materials with the purity of more than or equal to 99.99 percent to obtain tungsten carbide powder with the average grain diameter of 3 mu m;

(2) carrying out vacuum hot-pressing sintering treatment on the tungsten carbide powder obtained in the step (1) to obtain a tungsten carbide target blank; the vacuum hot-pressing sintering treatment specifically comprises the following steps:

(A) die filling: filling tungsten carbide powder into a graphite die and compacting, and ensuring that the flatness is 0.3 +/-0.1 mm after die filling;

(B) vacuumizing: putting the graphite mould into a vacuum sintering furnace, and vacuumizing until the absolute pressure in the furnace is 80 Pa;

(C) heating and pressurizing: heating to 1000 deg.C at a rate of 10 deg.C/min, heating to 1500 deg.C at a rate of 5 deg.C/min, and heating to 1850 deg.C at a rate of 3 deg.C/min; simultaneously pressurizing to 40MPa at the speed of 0.5 MPa/min;

(D) and (3) heat preservation and pressure maintaining treatment: preserving heat and pressure for 180 min;

(E) pressure removal: filling argon into the vacuum sintering furnace until the absolute pressure in the furnace is 0.03 MPa;

(F) and (3) cooling: cooling the mold with the furnace to 150 ℃, taking out the mold and airing to room temperature;

(3) machining the tungsten carbide target blank obtained in the step (2) to obtain a tungsten carbide target; the machining comprises the steps of grinding, cutting, finish machining, surface treatment, cleaning, drying and packaging which are sequentially carried out; the grinding is carried out on a plane grinding machine, and the specification of the grinding wheel of the adopted grinding machine is 80 meshes; the flatness achieved by the grinding is 0.03 +/-0.01 mm, and the cutting amount in each step is 0.03 mm; the cutting is carried out on a wire cutting machine; the fine machining is carried out on a milling machine, the specification of an adopted cylindrical grinding head is 400 meshes, and the amount of each step of cutter is 0.03 mm; the surface treatment comprises grinding and polishing which are sequentially carried out.

The results of the performance tests of the tungsten carbide targets obtained in examples 1 to 5 and comparative examples 1 to 6 are shown in Table 1.

TABLE 1

In the table, the density of the target was measured by archimedes drainage method; measuring the purity of the target material by a GDMS method; and (4) observing whether the microstructure has pores or not by combining with a scanning electron microscope photo of the surface of the target material.

As can be seen from Table 1: the tungsten carbide target material obtained in the embodiments 1-5 has excellent performance, the density is more than or equal to 99%, and the purity is more than or equal to 99.98%; comparative examples 1-4 show that the unreasonable settings of sintering temperature and pressing pressure in the vacuum hot-pressing sintering treatment can bring adverse effects to the target material performance; comparative example 5 the temperature rise process was changed to 2 temperature rise stages on the basis of example 1, resulting in a significant decrease in the target density and a certain number of pores in the microstructure; comparative example 6 the temperature rise process and the pressurization process were performed simultaneously on the basis of example 1, i.e. the separate heat preservation process was eliminated, the overall performance of the target material was also reduced, and the improvement of the coating quality was not facilitated.

Therefore, the density of the obtained tungsten carbide target is improved to more than 99 percent and the purity is up to more than 99.98 percent by reasonably controlling the sintering temperature and the pressing pressure of the vacuum hot-pressing sintering treatment, and meanwhile, the heat preservation treatment and the heat preservation and pressure maintaining treatment are carried out firstly, and the temperature rise process is divided into at least 3 temperature rise stages, so that the uniformity and the sputtering stability of crystal grains in the target are further improved, the microstructure is uniform and has no pores, and the wear resistance of the decorative coating film is obviously improved.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention, and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.