CN110590378A - Preparation method of homogenized and distributed silicon nitride ceramic material - Google Patents
Preparation method of homogenized and distributed silicon nitride ceramic material Download PDFInfo
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Abstract
A preparation method of a homogenized and distributed silicon nitride ceramic material belongs to the technical field of silicon nitride ceramic material preparation. Is characterized in that:<1>taking alpha-Si3N490 to 95 percent of submicron powder, and Y2O3Powder, TiC powder and Al2O3Preparing 5-7 groups of mixed powder materials according to the proportion of 1-5 percent of the powder materials respectively;<2>ball milling the components by using a planetary ball mill;<3>drying the powder subjected to ball milling in an oven;<4>dripping 2 percent of PVA solution which is prepared by uniform mixing, fully grinding, mixing and granulating;<5>sieving with 100 mesh sieve;<6>sealing and aging for 24 h;<7>respectively loading the powder into a steel mould in the radial direction and the axial direction by adopting a distributed method for pressing and forming;<8>and (3) putting the blank into a pressureless sintering furnace, and sintering at 1750 ℃ in a nitrogen atmosphere. The advantages are that: overcomes the defect of too much difference of internal performance of the silicon nitride ceramic material caused by the traditional unidirectional compactThe material performance can be effectively improved, and the production cost can be reduced.
Description
Technical Field
The invention belongs to the technical field of preparation of silicon nitride ceramic materials, and particularly relates to a preparation method of a homogenized and distributed silicon nitride ceramic material.
Technical Field
The silicon nitride ceramic material is called as the universal champion of the ceramics world due to the excellent characteristics of high temperature resistance, abrasion resistance, high strength, high toughness, corrosion resistance, high hardness, light specific gravity and the like, and has wide application and development prospects in aerospace, chemical metallurgy, machining and nuclear industries. Pressureless sintering is an economical sintering method in the industrial production of silicon nitride at present. Pressing silicon nitride powder into a green body is an important step in the pressureless sintering process of silicon nitride, which is the process of converting silicon nitride powder into a green body having a certain shape, volume and strength. During the pressing process of the silicon nitride blank, part of pressure loss is caused due to the violent displacement friction force between particles and a mold wall. A certain pressure gradient exists in the blank body, so that the density of different parts of the blank body is different, and finally, the performance of different parts of the silicon nitride ceramic product is different.
Chinese patent publication No. CN1944340A discloses a method for preparing silicon nitride ceramic by homogenization. The invention is that silicon nitride powder is firstly put into a steel mould to be pressed and formed mechanically, then the mechanically pressed silicon nitride biscuit is put into a rubber cylinder or a polyurethane, silicon rubber or polyurethane sponge mould, and is sealed and then is pressed in a cold isostatic press to achieve the aim of homogenizing the sintered silicon nitride ceramics. The method can only prepare the silicon nitride blank with simple shape, and the cold isostatic pressing die has higher preparation cost and complex process and is not suitable for wide application in the industrial production of silicon nitride.
Disclosure of Invention
The invention aims to provide a preparation method for preparing a homogenized and distributed silicon nitride ceramic material, which can effectively improve the material performance and reduce the production cost.
The invention is realized as follows, which is characterized in that the specific implementation steps are as follows:
<1>the raw materials comprise: alpha-Si3N490 to 95 percent of submicron powder, and Y2O3Submicron powder, TiC submicron powder and Al2O3The fine grain powder is prepared into 5-7 groups of mixed powder according to the proportion of 1-5 percent respectively.
<2>Ball milling: the above components were ball milled using a planetary ball mill. The grinding ball is made of silicon nitrideGrinding ball andthe proportion of the grinding balls is 1: 6, the rotating speed of the ball mill is 280r/min, positive and negative rotation is performed alternately every 20 minutes, the mass ratio of balls to materials to absolute ethyl alcohol is 3:2:1, and the ball milling time is 30 hours;
<3> drying: drying the ball-milled powder in an oven at the constant temperature of 120 ℃ for 5 hours;
<4> granulation: taking out the dried mixture from the oven, dripping 2% of PVA solution which is prepared by uniform mixing, pouring the PVA solution into an agate mortar for fully grinding and mixing, and granulating;
<5> sieving: then sieving the mixture by a 100-mesh sieve;
<6> staling: putting into a self-sealing bag, sealing and aging for 24 h;
<7> blank making: respectively loading 5-7 groups of aged powder into a steel die in the radial direction and the axial direction by adopting a distributed method for press forming, and finally measuring and weighing the size of the prepared biscuit;
<8> high temperature sintering: the green body is placed in a crucible coated with boron nitride and the crucible is placed in a pressureless sintering furnace. Vacuumizing, filling nitrogen, heating to 1450 deg.C at 20 deg.C/min, maintaining for 3 hr, heating to 1750 deg.C, maintaining for 3 hr, cooling, exhausting, and discharging.
Drawings
Figure 1 is a schematic view of radial loading in a steel die.
Figure 2 is a schematic view of the axial loading in a steel mould.
Detailed Description
Example 1
Proportioning raw materials: alpha-Si3N4Submicron powder in 95%, Y2O3Submicron powder, TiC submicron powder and Al2O3Preparing six groups of mixed powder materials according to the proportion of 2 percent, 1 percent and 2 percent of fine grain powder materials, and respectively marking as I-VI groups;
ball milling: the above components were ball milled using a planetary ball mill. The grinding ball is made of silicon nitrideGrinding ball andthe proportion of the grinding balls is 1: 6, the rotating speed of the ball mill is 280r/min, positive and negative rotation is performed alternately every 20 minutes, the mass ratio of balls to materials to absolute ethyl alcohol is 3:2:1, and the ball milling time is 30 hours;
thirdly, drying: drying the ball-milled powder in an oven at the constant temperature of 120 ℃ for 5 hours;
granulating: taking out the dried mixture from the oven, dripping 2% of PVA solution which is prepared by uniformly mixing, pouring into an agate mortar for fully grinding and mixing, and granulating;
sieving: then sieving the mixture by a 100-mesh sieve;
sixthly, ageing: putting into a self-sealing bag, sealing and aging for 24 h;
seventhly, blank manufacturing: and (3) filling the six groups of aged powder into a steel die in a radial direction by adopting a distributed method for compression molding, namely arranging the I-VI groups of powder in turn from the edge to the axis of the blank in the radial direction, as shown in figure 1.
And high-temperature sintering: and placing the blank into a crucible coated with boron nitride, and placing the crucible into a pressureless sintering furnace. Vacuumizing, filling nitrogen, heating to 1450 deg.C at 20 deg.C/min, maintaining for 3 hr, heating to 1750 deg.C, maintaining for 3 hr, cooling, exhausting, and discharging.
Example 2
alpha-Si as raw material3N4Submicron powders in a gradient of 94%, Y2O3Submicron powder, TiC submicron powder and Al2O3Fine grain powder 2%, 2%Preparing six groups of mixed powder materials according to the proportion of the components I to VI;
ball milling: the above components were ball milled using a planetary ball mill. The grinding ball is made of silicon nitrideGrinding ball andthe proportion of the grinding balls is 1: 6, the rotating speed of the ball mill is 280r/min, positive and negative rotation is performed alternately every 20 minutes, the mass ratio of balls to materials to absolute ethyl alcohol is 3:2:1, and the ball milling time is 30 hours;
thirdly, drying: drying the ball-milled powder in an oven at the constant temperature of 120 ℃ for 5 hours;
granulating: taking out the dried mixture from the oven, dripping 2% of PVA solution which is prepared by uniformly mixing, pouring into an agate mortar for fully grinding and mixing, and granulating;
sieving: then sieving the mixture by a 100-mesh sieve;
sixthly, ageing: putting into a self-sealing bag, sealing and aging for 24 h;
seventhly, blank manufacturing: and (3) filling the six groups of aged powder into a steel die in an axial direction by adopting a distributed method for compression molding, namely, arranging the I-VI groups of powder downwards in sequence from one end of the blank body, which is axially applied with a load, as shown in figure 2.
And high-temperature sintering: and placing the blank into a crucible coated with boron nitride, and placing the crucible into a pressureless sintering furnace. Vacuumizing, changing nitrogen twice, heating to 1450 deg.C at 20 deg.C/min, maintaining for 3 hr, heating to 1750 deg.C, maintaining for 3 hr, cooling, exhausting, and discharging.
The advantages of the present invention can be seen by comparing the examples of the present invention with the prior art.
Watch 1
Claims (1)
1. A preparation method of a homogenized and distributed silicon nitride ceramic material is characterized by comprising the following specific implementation steps:
<1>the raw materials comprise: alpha-Si3N490 to 95 percent of submicron powder, and Y2O3Submicron powder, TiC submicron powder and Al2O3Preparing 5-7 groups of mixed powder by the fine grain powder according to the proportion of 1-5 percent respectively;
ball milling, namely ball milling the components by using a planetary ball mill, wherein the material of the grinding balls is silicon nitride, the proportion of ø 10mm grinding balls to ø 5mm grinding balls is 1: 6, the rotating speed of the ball mill is 280r/min, positive and negative rotation is alternated every 20 minutes, the mass ratio of the balls to the materials to the absolute ethyl alcohol is 3:2:1, and the ball milling time is 30 hours;
<3> drying: drying the ball-milled powder in an oven at the constant temperature of 120 ℃ for 5 hours;
<4> granulation: taking out the dried mixture from the oven, dripping 2% of PVA solution which is prepared by uniform mixing, pouring the PVA solution into an agate mortar for fully grinding and mixing, and granulating;
<5> sieving: then sieving the mixture by a 100-mesh sieve;
<6> staling: putting into a self-sealing bag, sealing and aging for 24 h;
<7> blank making: respectively loading 5-7 groups of aged powder into a steel die in the radial direction and the axial direction by adopting a respectively distributed method for press forming, and finally measuring and weighing the size of the prepared biscuit;
<8> high temperature sintering: putting the blank into a crucible coated with boron nitride, putting the crucible into a pressureless sintering furnace, vacuumizing, filling nitrogen, heating to 1450 ℃ at the speed of 20 ℃/min, preserving heat for 3h, continuing heating to 1750 ℃, preserving heat for 3h, then cooling, exhausting and discharging.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114986661A (en) * | 2022-04-07 | 2022-09-02 | 辽宁伊菲科技股份有限公司 | Preparation method and device of silicon nitride sonar thermal imaging insulating strip |
| CN117819989A (en) * | 2024-01-04 | 2024-04-05 | 河源帝诺新材料有限公司 | Method for preparing silicon nitride fine and fine spheres by ionic crosslinking gel method |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN1799995A (en) * | 2005-12-21 | 2006-07-12 | 北京科技大学 | Method for synthesizing isotropic silicon nitride powder adopting layer type material-distribution |
| CN103992100A (en) * | 2014-06-10 | 2014-08-20 | 山东理工大学 | Process for preparing layered silicon nitride ceramic with high strength and high toughness by utilizing component gradient design |
| CN109731639A (en) * | 2018-12-25 | 2019-05-10 | 太原科技大学 | A method of piercing plug for seamless steel tubes is manufactured with silicon nitride ceramics |
-
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- 2019-09-19 CN CN201910885480.7A patent/CN110590378A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1799995A (en) * | 2005-12-21 | 2006-07-12 | 北京科技大学 | Method for synthesizing isotropic silicon nitride powder adopting layer type material-distribution |
| CN103992100A (en) * | 2014-06-10 | 2014-08-20 | 山东理工大学 | Process for preparing layered silicon nitride ceramic with high strength and high toughness by utilizing component gradient design |
| CN109731639A (en) * | 2018-12-25 | 2019-05-10 | 太原科技大学 | A method of piercing plug for seamless steel tubes is manufactured with silicon nitride ceramics |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114986661A (en) * | 2022-04-07 | 2022-09-02 | 辽宁伊菲科技股份有限公司 | Preparation method and device of silicon nitride sonar thermal imaging insulating strip |
| CN117819989A (en) * | 2024-01-04 | 2024-04-05 | 河源帝诺新材料有限公司 | Method for preparing silicon nitride fine and fine spheres by ionic crosslinking gel method |
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