CN102757225A

CN102757225A - Method for preparing oxide and silicon nitride product

Info

Publication number: CN102757225A
Application number: CN2012100000591A
Authority: CN
Inventors: 张拯; 雷复兴; 孙学义; 刘广彬
Original assignee: LUOYANG BEIYUAN SPECIAL CERAMICS CO Ltd
Current assignee: LUOYANG BEIYUAN NEW MATERIAL TECHNOLOGY Co.,Ltd.
Priority date: 2012-01-01
Filing date: 2012-01-01
Publication date: 2012-10-31
Anticipated expiration: 2032-01-01
Also published as: CN102757225B

Abstract

The invention discloses a method for preparing an oxide and silicon nitride product. By virtue of a production technology of the oxide and silicon nitride product, an oxide which is easy to cause liquid phase is added in the silicon nitride, and the silicon nitride is sintered under the high temperature through the generation of the liquid phase. The method specifically comprises the following steps of: a) preparing the following materials in percentage by weight: 70-80 wt% of Si3N4, 20-30 wt% of the oxide and a binding agent accounting 3-5 % of the weight of the Si3N4 and the oxide; b) mixing the materials; c) forming; d) drying; and e) sintering. The method for preparing the oxide and silicon nitride product, disclosed by the invention, has the characteristics of simple production technology, simple production equipment and high production efficiency.

Description

A kind of preparation method of oxide-bonded silicon nitride goods

Technical field

The present invention relates to the silicon nitride ceramics technical field, specifically relate to a kind of preparation method of oxide-bonded silicon nitride goods.

Background technology

Silicon nitride (Si ₃N ₄) in Si and N between with strong covalent bonds, so fusing point is high, hardness is high, intensity is high, Stability Analysis of Structures.Silicon nitride belongs to the high temperature infusible compound, and have the hot strength height, advantages such as the high temperature erosion resistance is strong, thermal expansivity is low, good heat conductivity, be a kind of very good high temperature ceramic material.

Silicon nitride can distillation decomposing more than 1900 ℃, can not produce liquid phase usually, is difficult to sinter into goods, so people add sintering aid usually silicon nitride is carried out sintering in silicon nitride.However, also need apply special means and just can sinter silicon nitride ceramics into, like reaction sintering, hot pressed sintering, pressure sintering, atmosphere protection or the like.In short, be exactly that silicon nitride only just can reach good sintering under high temperature (more than 1800 ℃) and condition of high voltage.

Summary of the invention

Technical problem to be solved by this invention provides the preparation method that a kind of production process is simple, produce the oxide-bonded silicon nitride goods that equipment is simple, production efficiency is high,

The preparation method of oxide-bonded silicon nitride goods of the present invention is referred from the production technology of oxide combined silicon carbide goods, in silicon nitride, adds the oxide compound that is easy to generate liquid phase, at high temperature makes silicon nitride reach sintering through producing liquid phase.Specifically may further comprise the steps:

A), batching

Raw material and proportioning thereof (weight percent) be as follows:

Si ₃N ₄ 70~80%

Oxide compound 20 ~ 30%

Add and account for Si ₃N ₄Wedding agent with oxide weight 3 ~ 5%;

Wherein, oxide compound is any one of fine silica powder, clay powder or mullite powder;

B), batch mixing

The raw material of said ratio is even in stirrer for mixing;

C), moulding

With the compound that makes compression moulding on hydropress, forming pressure is 100 ~ 120MPa;

D), drying

With pressed green body 80 ~ 100 ℃ * 6 ~ 10 hours dryings of warp in loft drier;

E), burn till

The exsiccant base substrate is packed in the high temperature kiln,, be incubated 6 ~ 10 hours through 1350 ~ 1450 ℃ of sintering.

Further, said Si ₃N ₄For silicon nitride content is 95 ~ 98%, granularity is less than 325 purpose silicon nitride powders.

Further, said fine silica powder granularity is less than 3000 orders.

Further, said clay powder granularity is less than 325 orders.

Further, said mullite powder degree is less than 325 orders.

Further, said wedding agent is any one of water glass, silicon sol, spent pulping liquor.

The preparation technology of oxide-bonded silicon nitride ceramics of the present invention has following characteristics:

1) oxide compound that, is added is not strict with performances such as chemical purity, particle finenesses;

2), moulding can be by the forming method of ordinary pottery products;

3) firing temperature is below 1450 ℃;

4) normal pressure-sintered, do not need special-purpose burning apparatus;

5) do not need atmosphere protection.

What need explanation is; Although physicochemical property, mechanical behavior under high temperature and the high temperature thermal property special means agglomerating of no use silicon nitride goods that kind of the oxide-bonded silicon nitride ceramics of the present invention's preparation are good; But production process is simple, the production equipment is simple, highly efficient in productivity, makes production cost very low.Therefore have the wide field of applying and market outlook.

Embodiment

A), batching; Raw material and proportioning are seen table 1.

Table 1

B), mix: it is even in stirrer for mixing with raw material to press table 1 proportioning.

C), moulding: compound packed into is molded into base substrate in wooden model or the metal die on the vibrations pressing machine, forming pressure is seen table 2.

D), drying: molding blank is put into loft drier or dry road drying, and drying temperature is seen table 2.

E), burn till: with the exsiccant base substrate sintering in the high temperature kiln of packing into, sintering temperature is seen table 2.

Table 2

The performance index of prepared mullite light-weight insulating brick are seen table 3.

Table 3

Claims

1. the preparation method of oxide-bonded silicon nitride goods is characterized in that: specifically may further comprise the steps: a), batching

Raw material and proportioning thereof (weight percent) be as follows:

Si ₃N ₄ 70~80%

Oxide compound 20 ~ 30%

Add and account for Si ₃N ₄Wedding agent with oxide weight 3 ~ 5%;

B), batch mixing

The raw material of said ratio is even in stirrer for mixing;

C), moulding

D), drying

E), burn till

2. the preparation method of oxide-bonded silicon nitride goods according to claim 1 is characterized in that: said Si ₃N ₄For silicon nitride content is 95 ~ 98%, granularity is less than 325 purpose silicon nitride powders.

3. the preparation method of oxide-bonded silicon nitride goods according to claim 1 is characterized in that: said fine silica powder granularity is less than 3000 orders.

4. the preparation method of oxide-bonded silicon nitride goods according to claim 1 is characterized in that: said clay powder granularity is less than 325 orders.

5. the preparation method of oxide-bonded silicon nitride goods according to claim 1 is characterized in that: said mullite powder degree is less than 325 orders.

6. the preparation method of oxide-bonded silicon nitride goods according to claim 1 is characterized in that: said wedding agent is any one of water glass, silicon sol, spent pulping liquor.