阅读说明：本技术 一种高密度ito靶的制备工艺 (Preparation process of high-density ITO target ) 是由 唐安泰 于 2020-12-15 设计创作，主要内容包括：本发明公开了一种高密度ITO靶的制备工艺,所述ITO靶材制备原材料为ITO粉末,将ITO粉末进行定量配制,并进行ITO靶材的制备工艺；所述制备工艺流程如下：还原阶段、制坯阶段、高温加压阶段、冷却排压阶段和高温煅烧阶段,高温烧结完成后的ITO靶材在经过高温加压、冷却排压阶段,实现内部热胀冷缩目的,使得晶体之间缝隙缩小,提高成型后的ITO靶材密度。本发明采用高温加压提高初坯中分子活性,比配合加压,将初坯粉末之间进行挤压,并后续进行冷却,通过热胀冷缩原理,再度将粉末之间的间隙再度缩小,配合加热进行成型,随后进行高温烧结,能够制成密度更高的ITO靶材。(The invention discloses a preparation process of a high-density ITO target, wherein the ITO target is prepared from ITO powder serving as a raw material, the ITO powder is quantitatively prepared, and the preparation process of the ITO target is carried out; the preparation process flow is as follows: the method comprises a reduction stage, a blank making stage, a high-temperature pressurizing stage, a cooling pressure discharging stage and a high-temperature calcining stage, wherein the ITO target after high-temperature sintering achieves the purpose of internal expansion and contraction after the high-temperature pressurizing, cooling pressure discharging stage, so that gaps among crystals are reduced, and the density of the formed ITO target is improved. According to the invention, high-temperature pressurization is adopted to improve the molecular activity in the primary blank, and the primary blank powder is extruded and then cooled, the gap between the powder is reduced again by the principle of thermal expansion and cold contraction, and the ITO target material with higher density can be prepared by heating and molding, and then sintering at high temperature.)

1. A preparation process of a high-density ITO target is characterized by comprising the following steps: the ITO target material preparation raw material is ITO powder, the ITO powder is quantitatively prepared, and the preparation process of the ITO target material is carried out;

the preparation process flow is as follows: the method comprises the steps of reduction, blank making, high-temperature pressurization, cooling and pressure discharge and high-temperature calcination;

the reduction stage is to carry out reduction reaction on single-phase ITO solid solution powder;

in the blank making stage, a mould pressing process is adopted, ITO powder after reduction reaction is quantitatively placed in a mould, and a hydraulic press is used for pressing the ITO powder into a specific shape;

in the high-temperature pressurizing stage, the stainless steel sleeve with the primary blank is arranged in a heating furnace, and one end of the heating furnace is provided with a pressurizing connector;

after the high-temperature pressurizing stage is finished, discharging gas in the stainless steel sleeve, maintaining the pressure of 50MPa in the stainless steel sleeve, taking the stainless steel sleeve out of the heating furnace, placing the stainless steel sleeve in a cooling bin, connecting a pressurizing interface at one end of the stainless steel sleeve with a pressure pump, arranging a pressure valve at the pressurizing interface, and communicating the pressure valve with the inside of the stainless steel sleeve;

the heating furnace heats the stainless steel sleeve, and the force pump pressurizes to stainless steel sleeve inside simultaneously, the heating and pressurization stage all adopts the classification formula, the classification formula flow of heating and pressurizing is as follows:

the first stage is as follows: the temperature in the heating furnace is raised to 800 ℃, a pressure pump applies pressure to the inside of the stainless steel sleeve to 50MPa, and the temperature and the pressure are maintained for 30min, and then the temperature and the pressure are raised in the next stage;

and a second stage: the temperature in the heating furnace is increased to 900 ℃, a pressure pump applies pressure to the inside of the stainless steel sleeve to 100MPa, and the temperature and the pressure are maintained for 30min, and then the temperature and the pressure are increased at the next stage;

and a third stage: the temperature in the heating furnace is increased to 1000 ℃, a pressure pump applies pressure to the inside of the stainless steel sleeve at 180MPa, and the constant temperature and pressure operation of the final stage is carried out after the temperature and the pressure are maintained for 1 h;

a fourth stage: the temperature in the heating furnace is increased to 1050 ℃, a pressure pump applies pressure to the inside of the stainless steel sleeve to be 200MPa, and the high-temperature pressurization stage operation is finished after the temperature and the pressure are maintained for 2-4 h;

and in the high-temperature calcination stage, the blank is taken out after cooling and pressure discharge are finished, and the blank is placed in a calcination furnace for high-temperature calcination, so that the finished ITO target is formed.

2. The process for preparing a high-density ITO target according to claim 1, wherein: the reduction reaction environment is a mixed gas of nitrogen and hydrogen, the mixed gas of nitrogen and hydrogen is used as the reduction reaction environment, the temperature is raised to 300-500 ℃, and the reduction reaction is promoted to be carried out; the ITO powder is subjected to reduction reaction, and the reduction degree is controlled to be 0.02-0.2%.

3. The process for preparing a high-density ITO target according to claim 1, wherein: the die is made of stainless steel materials, and the shape of the die can be made into different shapes according to actual production requirements so as to meet the requirements of actual production;

and the molding die pressing pressure is controlled to be 100-300MPa, the reduced ITO powder supports the primary blank, the primary blank is placed in a sealed stainless steel sleeve, and an isolation pad is sewn between the primary blanks so as to facilitate subsequent process machining operation.

4. The process for preparing a high-density ITO target according to claim 1, wherein: the cooling bin carries out the cooling and pressurization process in three stages to the stainless steel sleeve, carries out expend with heat and contract with cold with the inside ITO powder crystallization of primary blank, and the cooperation is pressurized, improves the density of primary blank.

5. The process for preparing a high-density ITO target according to claim 6, wherein: the cooling stage flow is as follows:

the first stage is as follows: placing a stainless steel sleeve in a cooling bin, reducing the pressure in the stainless steel sleeve from 200MPa to 50MPa, naturally cooling the stainless steel sleeve, reducing the temperature to be below 800 ℃, and carrying out cooling and pressurizing at the next stage;

and a second stage: after the temperature of the stainless steel sleeve is reduced to 800 ℃, the cooling bin cools the stainless steel sleeve in a mode of combining air cooling and spray water cooling, the pressure pump pumps air into the stainless steel sleeve, the pressure in the stainless steel sleeve is raised to 100MPa, and the stainless steel sleeve is kept stand for 1h for the next stage;

and a third stage: after the internal temperature of the stainless steel sleeve is reduced to be below 100 ℃, pumping air into the stainless steel sleeve by a pressure pump, increasing the pressure in the stainless steel sleeve to 150MPa, and maintaining the constant pressure for 1 h;

after cooling, slowly discharging air pressure in the stainless steel sleeve, recovering the air pressure in the stainless steel sleeve to standard atmospheric pressure, heating, pressurizing, cooling and pressurizing, heating, pressurizing and tightening the crystal inside the primary blank, cooling, contracting and pressurizing, reducing the gap between the crystals and having higher density.

6. The process for preparing a high-density ITO target according to claim 1, wherein: the calcination process is as follows: the target material is placed in a calcining furnace, 0.1-0.9MPa of oxygen is introduced into the calcining furnace, and the calcining furnace carries out high-temperature calcination on the blank material at the temperature of 1500-.

7. The process for preparing a high-density ITO target according to claim 8, wherein: in the high-temperature calcination process, the calcination temperature is divided into two stages:

the first stage is as follows: the temperature of the calcining furnace is controlled between 300 and 500 ℃, and the calcining time is 5 h;

and a second stage: the temperature of the calcining furnace is increased to 1500-1600 ℃, and high-temperature calcination is carried out for 5-10h again;

the ITO target material after high-temperature sintering is subjected to high-temperature pressurization, cooling and pressure discharge stages, so that the purposes of internal expansion and contraction are achieved, gaps among crystals are reduced, and the density of the formed ITO target material is improved.

Technical Field

The invention relates to the technical field of ITO target materials, in particular to a preparation process of a high-density ITO target.

Background

With the rapid development of information technology, a variety of electronic products appear in people's daily life, and an important display platform of information technology is a display screen, and the main material for manufacturing a flat liquid crystal display screen is ITO film transparent conductive glass, and ITO target material is an important raw material for manufacturing ITO film transparent conductive glass, so that the display screen has wide and important applications in the aspects of electronic industry and information industry. The existing preparation technology of the ITO target material mainly comprises a hot isostatic pressing method, a vacuum hot pressing method, a normal-temperature sintering method, a cold isostatic pressing method and the like, and the density of the ITO target material preparation has a certain limit, so that the target material with higher density can not be prepared, and further development of the electronic industry is limited.

After mass search, the Chinese invention patent with the publication number of CN105712703A, which is found in the prior art, discloses a preparation method of a high-purity high-density ITO target material, which comprises the following steps: adding pure water into self-made ITO powder to prepare slurry, then adding a dispersing agent, sanding in a sand mill, then adding a binder and a defoaming agent to carry out ball milling, and then carrying out spray granulation to obtain ITO granulation powder; putting the obtained ITO granulation powder into a die for prepressing and forming to obtain an ITO primary blank; forming the obtained ITO primary blank on a cold isostatic press to obtain an ITO biscuit; degreasing the obtained ITO biscuit in a degreasing furnace, and sintering in a sintering furnace in an oxygen atmosphere to obtain the high-purity high-density ITO target. The high-purity high-density ITO target material has more uniform components, is not easy to crack, and has high purity and high relative density.

In summary, the density of the ITO target prepared by the prior art is different, and the prior art cannot prepare the ITO target with the density exceeding 96%, thereby limiting the development of the prior electronic industry and the development of the manufacturing process of the liquid crystal display screen.

Disclosure of Invention

The invention aims to provide a preparation process of a high-density ITO target, which aims to solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme: a preparation process of a high-density ITO target comprises the steps of preparing an ITO target material by using ITO powder as a raw material, quantitatively preparing the ITO powder, and preparing the ITO target material;

the preparation process flow is as follows: the method comprises the steps of reduction, blank making, high-temperature pressurization, cooling and pressure discharge and high-temperature calcination;

the reduction stage is to carry out reduction reaction on single-phase ITO solid solution powder;

in the blank making stage, a mould pressing process is adopted, ITO powder after reduction reaction is quantitatively placed in a mould, and a hydraulic press is used for pressing the ITO powder into a specific shape;

in the high-temperature pressurizing stage, the stainless steel sleeve with the primary blank is arranged in a heating furnace, and one end of the heating furnace is provided with a pressurizing connector;

after the high-temperature pressurizing stage is finished, discharging gas in the stainless steel sleeve, maintaining the pressure of 50MPa in the stainless steel sleeve, taking the stainless steel sleeve out of the heating furnace, placing the stainless steel sleeve in a cooling bin, connecting a pressurizing interface at one end of the stainless steel sleeve with a pressure pump, arranging a pressure valve at the pressurizing interface, and communicating the pressure valve with the inside of the stainless steel sleeve;

the heating furnace heats the stainless steel sleeve, and the force pump pressurizes to stainless steel sleeve inside simultaneously, the heating and pressurization stage all adopts the classification formula, the classification formula flow of heating and pressurizing is as follows:

the first stage is as follows: the temperature in the heating furnace is raised to 800 ℃, a pressure pump applies pressure to the inside of the stainless steel sleeve to 50MPa, and the temperature and the pressure are maintained for 30min, and then the temperature and the pressure are raised in the next stage;

and a second stage: the temperature in the heating furnace is increased to 900 ℃, a pressure pump applies pressure to the inside of the stainless steel sleeve to 100MPa, and the temperature and the pressure are maintained for 30min, and then the temperature and the pressure are increased at the next stage;

and a third stage: the temperature in the heating furnace is increased to 1000 ℃, a pressure pump applies pressure to the inside of the stainless steel sleeve at 180MPa, and the constant temperature and pressure operation of the final stage is carried out after the temperature and the pressure are maintained for 1 h;

a fourth stage: the temperature in the heating furnace is increased to 1050 ℃, a pressure pump applies pressure to the inside of the stainless steel sleeve to be 200MPa, and the high-temperature pressurization stage operation is finished after the temperature and the pressure are maintained for 2-4 h;

and in the high-temperature calcination stage, the blank is taken out after cooling and pressure discharge are finished, and the blank is placed in a calcination furnace for high-temperature calcination, so that the finished ITO target is formed.

Preferably, the reduction reaction environment is a mixed gas of nitrogen and hydrogen, the mixed gas of nitrogen and hydrogen is used as the reduction reaction environment, and the temperature is raised to 300-500 ℃ to promote the reduction reaction; the ITO powder is subjected to reduction reaction, and the reduction degree is controlled to be 0.02-0.2%.

Preferably, the die is made of stainless steel materials, and the shape of the die can be made into different shapes according to actual production requirements so as to meet the requirements of actual production;

and the molding die pressing pressure is controlled to be 100-300MPa, the reduced ITO powder supports the primary blank, the primary blank is placed in a sealed stainless steel sleeve, and an isolation pad is sewn between the primary blanks so as to facilitate subsequent process machining operation.

Preferably, the cooling stage flow is as follows:

the first stage is as follows: placing a stainless steel sleeve in a cooling bin, reducing the pressure in the stainless steel sleeve from 200MPa to 50MPa, naturally cooling the stainless steel sleeve, reducing the temperature to be below 800 ℃, and carrying out cooling and pressurizing at the next stage;

and a second stage: after the temperature of the stainless steel sleeve is reduced to 800 ℃, the cooling bin cools the stainless steel sleeve in a mode of combining air cooling and spray water cooling, the pressure pump pumps air into the stainless steel sleeve, the pressure in the stainless steel sleeve is raised to 100MPa, and the stainless steel sleeve is kept stand for 1h for the next stage;

and a third stage: after the internal temperature of the stainless steel sleeve is reduced to be below 100 ℃, pumping air into the stainless steel sleeve by a pressure pump, increasing the pressure in the stainless steel sleeve to 150MPa, and maintaining the constant pressure for 1 h;

after cooling, slowly discharging air pressure in the stainless steel sleeve, recovering the air pressure in the stainless steel sleeve to standard atmospheric pressure, heating, pressurizing, cooling and pressurizing, heating, pressurizing and tightening the crystal inside the primary blank, cooling, contracting and pressurizing, reducing the gap between the crystals and having higher density.

Preferably, the calcination process is as follows: the target material is placed in a calcining furnace, 0.1-0.9MPa of oxygen is introduced into the calcining furnace, and the calcining furnace carries out high-temperature calcination on the blank material at the temperature of 1500-.

Preferably, in the high-temperature calcination process, the calcination temperature is divided into two stages:

the first stage is as follows: the temperature of the calcining furnace is controlled between 300 and 500 ℃, and the calcining time is 5 h;

and a second stage: the temperature of the calcining furnace is increased to 1500-1600 ℃, and high-temperature calcination is carried out for 5-10h again;

the ITO target material after high-temperature sintering is subjected to high-temperature pressurization, cooling and pressure discharge stages, so that the purposes of internal expansion and contraction are achieved, gaps among crystals are reduced, and the density of the formed ITO target material is improved.

Compared with the prior art, the invention has the beneficial effects that: according to the invention, a mode of combining high-temperature pressurization and cooling pressure discharge is adopted, the ITO primary blanks are subjected to high-temperature heating and pressurized extrusion at the same time, gaps among the primary blanks are extruded, the internal density of the primary blanks is preliminarily improved, cooling shrinkage is carried out after pressurization molding, the gaps among the primary blanks are further shrunk again, the pressurized extrusion is matched for molding, and after high-temperature calcination molding, ITO target materials with the density exceeding 96% can be prepared, so that the ITO target materials required by the development of the existing electronic industry can be met.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front", "rear", "both ends", "one end", "the other end", and the like indicate orientations or positional relationships only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "disposed," "connected," and the like are to be construed broadly, such as "connected," which may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The invention provides three embodiments: a preparation process of a high-density ITO target comprises the steps of preparing an ITO target material into ITO powder, quantitatively preparing the ITO powder, and preparing the ITO target material;

the preparation process flow is as follows: the method comprises a reduction stage, a blank making stage, a high-temperature pressurizing stage, a cooling and pressure discharging stage and a high-temperature calcining stage.

The reduction stage is to carry out reduction reaction on single-phase ITO solid solution powder;

the reduction reaction environment is a mixed gas of nitrogen and hydrogen, the mixed gas of nitrogen and hydrogen is used as the reduction reaction environment, the temperature is raised to 300-500 ℃, and the reduction reaction is promoted to be carried out;

the ITO powder is subjected to reduction reaction, and the reduction degree is controlled to be 0.02-0.2%.

In the blank making stage, a mould pressing process is adopted, ITO powder after reduction reaction is quantitatively placed in a mould, and a hydraulic press is used for pressing the ITO powder into a specific shape;

the die is made of stainless steel materials, and the shape of the die can be made into different shapes according to the actual production requirement so as to meet the actual production requirement;

and controlling the molding and die pressing pressure to be 100-300MPa, supporting the reduced ITO powder to the primary blank, placing the primary blank in a sealed stainless steel sleeve, and sewing an isolation pad between the primary blanks so as to facilitate subsequent process machining operation.

The first embodiment is as follows:

in the high-temperature pressurizing stage, a stainless steel sleeve with an initial blank is arranged in a heating furnace, and one end of the heating furnace is provided with a pressurizing connector;

a pressurizing interface at one end of the stainless steel sleeve is connected with a pressure pump, and a pressure valve is arranged at the pressurizing interface and communicated with the inside of the stainless steel sleeve;

the heating furnace heats the stainless steel sleeve, the pressure pump pressurizes the inside of the stainless steel sleeve, and the heating stage and the pressurizing stage are classified.

The step-by-step heating and pressurizing process comprises the following steps:

the first stage is as follows: the temperature in the heating furnace is raised to 800 ℃, a pressure pump applies pressure to the inside of the stainless steel sleeve to 50MPa, and the temperature and the pressure are maintained for 30min, and then the temperature and the pressure are raised in the next stage;

and a second stage: the temperature in the heating furnace is increased to 900 ℃, a pressure pump applies pressure to the inside of the stainless steel sleeve to 100MPa, and the temperature and the pressure are maintained for 30min, and then the temperature and the pressure are increased at the next stage;

and a third stage: the temperature in the heating furnace is increased to 1000 ℃, a pressure pump applies pressure to the inside of the stainless steel sleeve at 180MPa, and the constant temperature and pressure operation of the final stage is carried out after the temperature and the pressure are maintained for 1 h;

a fourth stage: and (3) increasing the temperature in the heating furnace to 1050 ℃, applying pressure of 200MPa to the inside of the stainless steel sleeve by using a pressure pump, and finishing the operation in the high-temperature pressurizing stage after keeping the temperature and the pressure for 2-4 h.

Example two:

after the high-temperature pressurizing stage is finished, discharging gas in the stainless steel sleeve, maintaining the pressure of 50MPa in the stainless steel sleeve, taking the stainless steel sleeve out of the heating furnace, and placing the stainless steel sleeve in a cooling bin;

the cooling bin carries out the cooling and pressurization process in three stages to the stainless steel sleeve, carries out expend with heat and contract with cold with the ITO powder crystallization of the inside of primary blank, and the cooperation is pressurized, improves the density of primary blank.

The cooling stage flow is as follows:

the first stage is as follows: placing a stainless steel sleeve in a cooling bin, reducing the pressure in the stainless steel sleeve from 200MPa to 50MPa, naturally cooling the stainless steel sleeve, reducing the temperature to be below 800 ℃, and carrying out cooling and pressurizing at the next stage;

and a second stage: after the temperature of the stainless steel sleeve is reduced to 800 ℃, the cooling bin cools the stainless steel sleeve in a mode of combining air cooling and spray water cooling, the pressure pump pumps air into the stainless steel sleeve, the pressure in the stainless steel sleeve is raised to 100MPa, and the stainless steel sleeve is kept stand for 1h for the next stage;

and a third stage: after the internal temperature of the stainless steel sleeve is reduced to be below 100 ℃, pumping air into the stainless steel sleeve by a pressure pump, increasing the pressure in the stainless steel sleeve to 150MPa, and maintaining the constant pressure for 1 h;

after cooling, slowly discharging air pressure in the stainless steel sleeve, recovering the air pressure in the stainless steel sleeve to standard atmospheric pressure, heating, pressurizing, cooling and pressurizing, heating, pressurizing and tightening the crystal inside the primary blank, cooling, contracting and pressurizing, reducing the gap between the crystals and having higher density.

Example three:

in the high-temperature calcination stage, the blank is taken out after cooling and pressure discharge are finished, and the blank is placed in a calcination furnace for high-temperature calcination, so that a finished ITO target is formed;

the calcination process is as follows: the target material is placed in a calcining furnace, oxygen of 0.1-0.9MPa is introduced into the calcining furnace, and the calcining furnace carries out high-temperature calcination on the blank material at the temperature of 1500-.

In the high-temperature calcination process, the calcination temperature is divided into two stages:

the first stage is as follows: the temperature of the calcining furnace is controlled between 300 and 500 ℃, and the calcining time is 5 h;

and a second stage: the temperature of the calcining furnace is increased to 1500-1600 ℃, and high-temperature calcination is carried out for 5-10h again;

the ITO target material after high-temperature sintering is subjected to high-temperature pressurization, cooling and pressure discharge stages, so that the purposes of internal expansion and contraction are achieved, gaps among crystals are reduced, and the density of the formed ITO target material is improved.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.