CN1433999A

CN1433999A - Process for synthesizing superfine aluminium nitride powder and aluminium based heterogeneous ceramic powder by SHS method

Info

Publication number: CN1433999A
Application number: CN 02100196
Authority: CN
Inventors: 葛昌纯; 陈克新; 李江涛
Original assignee: University of Science and Technology Beijing USTB
Current assignee: University of Science and Technology Beijing USTB
Priority date: 2002-01-22
Filing date: 2002-01-22
Publication date: 2003-08-06
Anticipated expiration: 2022-01-22
Also published as: CN1216010C

Abstract

The present invention provides a method for synthesizing ultrafine AlN ceramic powder and AlN base heterogeneous ceramic powder by SHS process. For preparation of AlN powder body the original reactant composition includes 50-90 wt% of Al powder and 10-50 wt% of AlN powder, the density of biscuit is 35-60% and the pressure of nitrogen gas is 1-30 MPa. For AlN/ZrN/Al3Zr composite phase ceramic powder the original reactant powder composition includes 0-40 wt% of AlN powder, 0-30 wt% of ZrN powder, 10-85 wt% of Al powder and 30-70 wt% of Zr powder, density of biscuit is 35-50%, the nitrogen gas pressure for SHS reaction is 1-30 MPa. For AlN/ZrN composite phase ceramic powder the original reactant powder composition includes 70-80 wt% of Zr powder and 20-30 wt% of AiN powder, density of biscuit is 35-50%.

Description

With the method that spreads synthesizing superfine aluminium nitride and aluminum-nitride-based complex phase ceramic powder certainly

Technical field:

The present invention relates to a class by self propagating high temperature synthetic (self-propagating high-temperaturesynthesis, SHS) the ultra-fine AlN ceramic powder and the AlN base complex phase ceramic powder of method preparation.

Background technology

Since The former Russian scholar A.G.Merzhanov in 1967 and I.P.Borovinskaya found the SHS phenomenon, SHS was one of most active research direction in Materials Science and Engineering field always.Its basic characteristics are: the outside necessary energy that provides is provided, bring out the local chemical reaction (this process be called light) that takes place of high heat-producing chemical reaction system, form chemical reaction forward position (being combustion wave), after this chemical reaction is under self exothermic support, continue to move ahead, show as combustion wave and spread whole reaction system, last synthetic materials.The most outstanding advantage of SHS synthesis technique is that save energy, technology are simple, synthetics purity is high.So adopt the product of SHS explained hereafter to develop into more than 500 kinds so far.But these products are mainly by solid-solid reaction, and the burning of gas-solid system is synthetic, is reflected at and is undertaken by gas phase and solid state reaction under the condition of high voltage, and intrapore gas is not enough can to carry out fully in the influence reaction, and the thawing of solid phase can hinder the infiltration of gas.Its reaction mechanism is more complicated, and technology is restive.

Aluminium nitride has that density is low, thermal conductivity is high, specific inductivity is low, resistivity is high, performance such as thermal expansivity, the heat-shock resistance that is complementary with silicon is good, not only be used as the substrate and the packaged material of super large-scale integration first-selection, and, good prospects for application is also arranged as structural ceramics along with improving constantly of its performance.But traditional method for preparing AlN need be carried out under the heat condition, long, power consumption height of cycle, powder cost height, has seriously limited applying of AlN.The synthetic aluminium nitride of SHS is up-and-coming low price technology of preparing because its power consumption less, is swift in response, product purity height, with low cost.But because some basic theory and technology problems also do not obtain fine solution, the technology of the synthetic AlN of current combustion is used as yet on a large scale.States such as existing China, Russia, U.S., Japan and Korea S. research and solve the SHS composition problem of AlN just down energetically.

The international monopoly that relates to burning synthesizing superfine AlN ceramic powder and AlN base complex phase ceramic powder has the Japanese Patent of YamadaOsamu application " to be equipped with BN, AlN and Si by burning synthesis for preparing ₃N ₄" (JP2000264608).But the synthetic sample weight of this patent is very little, lights with laser, and cost is very high.The United States Patent (USP) " preparation method of aluminium nitride " of application such as Taiwan Yu Wen-Liang (US5846508).This patent adopts ammonium halide as nitrogenous source, and synthetic sample weight is very little, can not realize large size and even large-scale production.

Summary of the invention:

The present invention is by control reaction temperature and pressure, and adds suitable thinner, with the synthetic large size AlN base (φ 120mm) completely of SHS technology, prepared ultra-fine AlN ceramic powder and AlN base complex phase ceramic powder.

Composition proportion for the preparation primitive reaction thing of AlN (aluminium nitride) powder is: the Al powder of 50-90wt% and the AlN powder of 10-50wt%, and wt% is weight percentage; The density of biscuit is 35-60%, nitrogen pressure 1-30MPa.

For AlN/ZrN/Al ₃Zr complex phase ceramic powder, the composition proportion of primitive reaction thing powder is the AlN powder of 0-40wt%, the ZrN powder of 0-30wt%, the Al powder of 10-85wt% and the Zr powder of 30-70wt%, the density of biscuit is 35-50%, the nitrogen pressure of SHS reaction is 1--30MPa.

For AlN/ZrN complex phase ceramic powder, the composition proportion of primitive reaction thing powder is the Zr powder of 70-80wt% and the AlN powder of 20-30wt%, and the density of biscuit is 35-50%, and the nitrogen pressure of SHS reaction is 1--30MPa.

Original proportioning for the reactant of AlN-SiC sosoloid is that Si and C are 0-85atm%, and Al is 15-100atm%, and atm% is an atomic percent, and nitrogen gas pressure is 1--30MPa.

Principle and advantage that this law is bright are summarized as follows:

Recent studies show that, AlN can be used as the important composition composition of sintering metal and complex phase ceramic owing to its superior mechanical property, is expected to be widely used at structural ceramic material.Its technical process is as follows: (1) powder is by specifying the proportioning preparation, (2) ball milling 6 hours, and the oven dry of (3) powder is crossed 100 mesh sieves and (4) the powder combustion chamber of packing into is lighted.

Because the fusing point of metallic aluminium is lower, fusion can take place in combustion processes reunite, hinder the infiltration of nitrogen, so the raising nitrogen pressure adds the AlN thinner in the Al powder, reduce biscuit density, to improve the perviousness of nitrogen, be the key that improves Al powder nitridation.Specimen size has material impact to the combustion processes of SHS AlN simultaneously, tangible secondary nitrogenize peak appears in large dimension specimen in combustion processes, and the burning behavior of the different sites of large dimension specimen own shows different features under different biscuit density and nitrogen pressure condition.As structural ceramics, aluminium nitride has the not high shortcoming of physical strength.Therefore utilize the advantage of AlN pottery, avoid its shortcoming, on the basis of aluminium nitride, design heterogeneous composite material, to obtain the multiple stack advantage of performance.In the Al-Zr-N system, the AlN/ZrN complex phase ceramic combines the superior mechanical property of AlN and ZrN; Simultaneously than under the low condition Al is arranged at nitrogen pressure ₃Zr occurs mutually, and Al ₃The role of bonding phase has been played the part of at the mutually crystal boundary places that are distributed in AlN and ZrN of Zr more, has realized being difficult in gas-solid system the synchronous densification of realization in the SHS building-up process.

As a kind of important structural ceramic material, silicon carbide has the covalent bonds characteristic of height, is basic stupalith becomes fields such as hot machine, hot environment and chemical with its high rigidity, wear resistance and chemical stability research application at present with silicon carbide.α-SiC (2H) has similar structure with AlN, and on valency and unit cell parameters very big similarity is arranged.The matrix material that structure that both are similar and high-temperature behavior mean both is very helpful to the improvement of material property.SHS technology has been opened up the application prospect for preparing high-purity AlN-SiC sosoloid at a low price.

Description of drawings:

Accompanying drawing 1 is SHS of the present invention reaction chamber structural representation, and ignition wire 1 among the figure, reactant base substrate 2, thermometric thermopair 3, sample table 4.

Embodiment:

Example 1:SHS synthesizing superfine aluminium nitride powder

Test used aluminium powder purity greater than 99%, granularity is the 250-300 order; AlN purity is 99.4%, and granularity is less than 300 orders.Reactant content: Al is 80wt%, and AlN is 20wt%.For preventing the AlN hydrolysis, be medium with acetone, ball milling is 6 hours in the agate jar, and after the oven dry, pine is loaded in the combustion chamber in air, or is molded into certain powder base with spacing, and the diameter of powder base and loose reaction cartridge thing is 120mm.Light under the nitrogen pressure of 7MPa, prepared aluminium nitride nitrogenize is complete, and its specific surface is 2-6m ²/ g, equivalent grain size is 0.3-0.9 μ m.

The synthetic AlN/ZrN/Al of example 2:SHS ₃Zr complex phase ceramic powder

Al and AlN powder property are with example 1 in the primitive reaction thing.Zr powder purity is greater than 98%, and granularity is less than 200 orders.

The composition proportion of powder is the AlN powder of 31wt%, the Al powder of 15.8wt% and the Zr powder of 53.2wt%, and the density of biscuit is 45%, the nitrogen pressure 5MPa of SHS reaction, products therefrom is AlN/ZrN/Al ₃Zr complex phase ceramic powder, particle diameter is between 2-5 μ m.

The synthetic AlN/ZrN complex phase ceramic powder of example 3:SHS

Al and AlN powder property are with example 1 in the primitive reaction thing.ZrN powder purity is greater than 98%, and granularity is less than 300 orders.

The composition proportion of powder is the Al powder of 80wt% and the ZrN powder of 20wt%, and the density of biscuit is 45%, the nitrogen pressure 5MPa of SHS reaction, and products therefrom is an AlN/ZrN complex phase ceramic powder, particle diameter is between 2-5 μ m.

The synthetic AlN-SiC sosoloid of example 4:SHS

Al and AlN powder property are with example 1 in the primitive reaction thing.Si powder and C powder purity are greater than 98%, and granularity is less than 200 orders.

The original proportioning of the reactant of AlN-SiC sosoloid is that Si and C are 50atm%, and Al is 50atm%, and nitrogen gas pressure is 5MPa.Behind the prepared AlN-SiC sosoloid hot pressed sintering, performance is: bending strength 510MPa, HRA=93, K _1C=6.21MPam ^1/2

Claims

1, the method for synthetic AlN powder of a kind of self propagating high temperature and AlN base complex phase ceramic powder is characterized in that: AlN powder synthetic, and the composition proportion of primitive reaction thing is: the Al powder of 50-90wt% and the AlN powder of 10-50wt%; The density of biscuit is 35-60%, and wt% is weight percentage, nitrogen pressure 1--30MPa.

2, a kind of the method for claim 1 is characterized in that: for AlN/ZrN/Al ₃Zr complex phase ceramic powder, the composition proportion of primitive reaction thing powder is the AlN powder of 0-40wt%, the ZrN powder of 0-30wt%, the Al powder of 10-85wt% and the Zr powder of 30-70wt%, the density of biscuit is 35-50%, the nitrogen pressure of SHS reaction is 1--30MPa.

3, a kind of preparation method as right 1, it is characterized in that: for AlN/ZrN complex phase ceramic powder, the composition proportion of primitive reaction thing powder is the Zr powder of 70-80wt% and the AlN powder of 20-30wt%, and the density of biscuit is 35-50%, and the nitrogen pressure of SHS reaction is 1--30MPa.

4, a kind of preparation method as right 1 is characterized in that: the original proportioning for the reactant of AlN-SiC sosoloid is that Si and C are 0-85atm%, and Al is 15-100atm%, and atm% is an atomic percent, and nitrogen gas pressure is 1--30MPa.