CN100436375C - Process for preparing coated ZrB2 composite powder - Google Patents

Abstract

The present invention relates to a preparation process of clad inorganic powder with an anti-oxidation property, particularly to a preparation process of clad ZrB2 composite powder, which is characterized in that the preparation process comprises the following steps: 1) ZrB2 powder and water are uniformly mixed and stirred in the proportion of 1 gram: 50 to 1000 milliliters to obtain the slurry of the ZrB2 powder and the water; 2) 1 to 100 saline solutions are added into the slurry in the proportion of the ZrB2 powder to the saline solutions equaling to 1 gram: 50 to 1000 milliliters; meanwhile, a sedimentation agent with the pH value of 8 to 12 are added into the slurry, and the addition of the sedimentation agent keeps the pH value of the slurry from 7 to 11.5; 3) the composite powder with a cladding layer of which the front body is coated with the ZrB2 powder is obtained, and the sedimentation agents are substances generated in a water solution containing hydroxyl ions; 3) the composite powder is washed, dried at the temperature of 80 to 150 DEG C and calcined at the temperature of 300 to 700 DEG C to obtain the clad ZrB2 composite powder. The preparation process has the advantages of simple and convenient operation, easy control and low energy consumption; the prepared clad ZrB2 composite powder has the characteristic of favorable anti-oxidation property at high temperature.

Description

Covered ZrB 2The preparation method of composite granule

Technical field

The present invention relates to a kind of preparation method, relate in particular to a kind of covered ZrB with covered inorganic powder of antioxidant property ₂The preparation method of composite granule.

Background technology

The development of modern high-temperature technology requires material to possess the excellent high-temperature over-all properties to adapt to harsh operating environment.Oxide compound-non-oxidized substance matrix material is the rising high-temperature structural material of a class, and it utilizes the complementation of material property, makes material reach complex optimum, ZrB ₂Diphase ceramic material is exactly wherein a kind of.

ZrB ₂Pottery have high-melting-point (3040 ℃), high rigidity (88～91HRA), high strength (ultimate compression strength, tensile strength are respectively 1555.3MPa, 460MPa), (specific conductivity is 16.6 * 10 to good conductivity ^-5Ω cm, temperature coefficient of resistance are 1.76 * 10 ³℃ ^-1), good characteristics such as (20 ℃ of thermal conductivities are 24.3W/ (mK)) of thermal conductivity and in fields such as high temperature resistant structure ceramics, matrix material, electrode materials, thin-film material, refractory materials, nuclear control material, being applied.ZrB ₂The problem that the application of pottery mainly faces is easy oxidation under the high temperature, intensity is low and the acquisition of DB is relatively more difficult, and cost is higher, thereby has limited the Application Areas of material.ZrB ₂Powder is as ZrB ₂The stupalith raw material, the performance of its powder directly influences ZrB ₂The performance of stupalith.

Along with the novel material technology of preparing to the microcosmic development that becomes more meticulous, the reunion of powder and scattering problem have become the bottleneck of preparation and development novel material and superfine powder, the process for treating surface of powder becomes more and more important.It is exactly a kind of special methods of process for modifying surface that powder coats, and is exactly as nuclear, in the method for one or more other particles formation composite particless of its surface coating with a kind of particle.The particle coating technology not only can prepare multi-functional composite particles, but also is widely used for improving particle surface.Therefore, the ultrafine particle coating technology is widely used in stupalith, electronic material, biomaterial, pharmaceutical industries, coating, paint, powder metallurgy and military field.At present, covered TiO has appearred ₂, composite granule such as SiC, graphite, covered ZrB does not also appear ₂Composite granule.

Summary of the invention

The objective of the invention is to overcome ZrB ₂The at high temperature easily oxidized weak point that causes performance to reduce of stupalith provides the covered ZrB that antioxidant property is good under a kind of high temperature ₂The preparation method of composite granule.

To achieve these goals, technical scheme of the present invention is: covered ZrB ₂The preparation method of composite granule is characterized in that it comprises the steps:

1). with ZrB ₂Powder and water restrain by 1: the mixed of 50-1000 milliliter stirs, and obtains ZrB ₂The slurry of powder and water;

2). add salts solution in slurry, constant temperature stirs in 10～100 ℃; Wherein the add-on of salts solution is pressed ZrB ₂Powder: salts solution=1 gram: the ratio of 50-1000 milliliter adds, described salts solution is can produce sedimentary material in the solution of hydroxide ion is arranged, and is specially aluminum nitrate, Tai-Ace S 150, aluminum chloride, Yttrium trinitrate, Yttrium trichloride, yttrium sulfate or hypochlorous acid zirconium; The concentration of salts solution is 0.001-30mol/L; Adding the pH value simultaneously in slurry is the precipitation agent of 8-12, and the add-on of precipitation agent is to make the pH value of slurry remain 7-11.5, with the stirring that agitator does not stop, after salts solution dropwises, continues to stir 0.5～6 hour, and the precursor that obtains coating layer coats ZrB ₂The composite granule of powder; The material of described precipitation agent in the aqueous solution, there being hydroxide ion to produce;

3). with step 2) washing of the composite granule that obtains, in 80～150 ℃ of dryings, 300～700 ℃ of calcinings, product.

It is described that can to produce the described material that has hydroxide ion to produce in the aqueous solution of sedimentary material in the solution of hydroxide ion is arranged be ammoniacal liquor, urea or sodium hydroxide etc.

The present invention is with ZrB ₂Raw material carries out surface treatment, is introduced in the throw out (being the presoma of coating layer) that can produce sedimentary material in the solution of hydroxide ion and coats ZrB ₂Powder, the covered ZrB that antioxidant property is good and high-temperature behavior is excellent under the preparation high temperature ₂Composite granule.Its mechanism is: 1) coating layer has good oxidation-resistance; 2) coating particles is at ZrB ₂The surface forms compact isolating layer and makes ZrB ₂Not oxidized.That the present invention has is simple, convenient, be easy to control, less energy consumption, the covered ZrB of preparation ₂The composite granule raw material has good physics, chemical property, and the coating character of the accurate controlling packet coating of pH value of concentration that can be by regulating salts solution and precipitation agent, as: thickness, density, homogeneity etc.ZrB ₂Transmission electron microscope photo-TEM before and after powder granule coats, as Fig. 2, shown in Figure 3, Fig. 2 and Fig. 3 have relatively illustrated by the present invention's operation to prepare the good covered ZrB of covering property ₂Composite granule.

Description of drawings

Fig. 1 is a process flow sheet of the present invention

Fig. 2 is ZrB ₂Transmission electron microscope photo before powder granule coats-TEM figure

Fig. 3 is ZrB ₂Transmission electron microscope photo after powder granule coats-TEM figure

Embodiment

In order to understand the present invention better, further illustrate content of the present invention below in conjunction with Fig. 1, embodiment, but content of the present invention not only is confined to the following examples.

Embodiment 1:

With 3 gram ZrB ₂Powder adds in 200 ml waters, and ultra-sonic dispersion 5 minutes stirs, and obtains ZrB ₂The slurry of powder and water; With at the uniform velocity splashing into mixing solutions 300ml (the 0.12mol/L aluminum nitrate of 150ml and the 0.2mol/L Yttrium trinitrate of 150ml) in 180 fens clockwise slurries, the precipitation agent ammoniacal liquor that splashes into pH=11 is simultaneously regulated ZrB ₂The pH value of slurry is 9 always, with the stirring that agitator does not stop, after mixing solutions dropwises, continues to stir 1 hour, and makes the pH value remain 9, and the precursor that obtains coating layer coats ZrB ₂The composite granule of powder; Be taken up in order of priority with deionized water and this composite granule of absolute ethanol washing three times and once, with its 80 ℃ of oven dry, 500 ℃ of calcinings have just obtained Al again ₂O ₃And Y ₂O ₃The common ZrB that coats ₂The covered ZrB of powder granule ₂Composite granule.Covered ZrB ₂The coating thickness of composite granule is approximately 30nm, densification and even.

Embodiment 2:

With 3 gram ZrB ₂Powder adds in 200 ml waters, and ultra-sonic dispersion 5 minutes stirs, and obtains ZrB ₂The slurry of powder and water; At the uniform velocity splash into 0.05mol/L hypochlorous acid zirconium solution 200ml in the clockwise slurry with 120 minutes, the precipitation agent ammoniacal liquor that splashes into pH=11 is simultaneously regulated ZrB ₂The pH value of slurry is 9 always, with the stirring that agitator does not stop, after the hypochlorous acid zirconium solution dropwises, continues to stir 1 hour, and makes the pH value remain 9, and the precursor that obtains coating layer coats ZrB ₂The composite granule of powder; Be taken up in order of priority with deionized water and this composite granule of absolute ethanol washing three times and once, with its 100 ℃ of oven dry, 600 ℃ of calcinings have just obtained ZrO again ₂Coat ZrB ₂The covered ZrB of powder granule ₂Composite granule.Covered ZrB ₂The composite granule coating thickness is approximately 25nm, densification and even.

Embodiment 3:

With 3 gram ZrB ₂Powder adds in 150 ml waters, and ultra-sonic dispersion 5 minutes stirs, and obtains ZrB ₂The slurry of powder and water; With the 0.15mol/L yttrium sulfate solution that at the uniform velocity splashes into 150ml in 180 fens clockwise slurries, the sodium hydroxide solution precipitation agent that splashes into pH=10 is simultaneously regulated ZrB ₂The pH value of slurry is 9 always, with the stirring that agitator does not stop, after mixing solutions dropwises, continues to stir 1 hour, and makes the pH value remain 9, and the precursor that obtains coating layer coats ZrB ₂The composite granule of powder; Be taken up in order of priority with deionized water and this composite granule of absolute ethanol washing three times and once, with its 80 ℃ of oven dry, 500 ℃ of calcinings have just obtained Y again ₂O ₃Coat ZrB ₂The covered ZrB of powder granule ₂Composite granule.Covered ZrB ₂The coating thickness of composite granule is approximately 20nm, densification and even.

Embodiment 4:

With 3 gram ZrB ₂Powder adds in 200 ml waters, and ultra-sonic dispersion 5 minutes stirs, and obtains ZrB ₂The slurry of powder and water; At the uniform velocity splash into 1.0mol/L liquor alumini chloridi 200ml in the clockwise slurry with 120 minutes, the urea precipitation agent that splashes into pH=11 is simultaneously regulated ZrB ₂The pH value of slurry is 8.5 always, with the stirring that agitator does not stop, after liquor alumini chloridi dropwises, continues to stir 1 hour, and makes the pH value remain 8.5, and the precursor that obtains coating layer coats ZrB ₂The composite granule of powder; Be taken up in order of priority with deionized water and this composite granule of absolute ethanol washing three times and once, with its 80 ℃ of oven dry, 500 ℃ of calcinings have just obtained Al again ₂O ₃Coat ZrB ₂The covered ZrB of powder granule ₂Composite granule.Covered ZrB ₂The coating thickness of composite granule is approximately 25nm, densification and even.

Embodiment 5:

With 3 gram ZrB ₂Powder adds in 200 ml waters, and ultra-sonic dispersion 5 minutes stirs, and obtains ZrB ₂The slurry of powder and water; With at the uniform velocity splashing into mixing solutions 375ml (the 1.0mol/L Yttrium trichloride of the 1.2mol/L aluminum nitrate of 150ml, the 1.0mol/L Yttrium trinitrate of 75ml, 75ml and the 1.0mol/L Tai-Ace S 150 of 75ml) in 180 fens clockwise slurries, the precipitation agent ammoniacal liquor that splashes into pH=11.5 is simultaneously regulated ZrB ₂The pH value of slurry is 9.5 always, with the stirring that agitator does not stop, after mixing solutions dropwises, continues to stir 1 hour, and makes the pH value remain 9.5, and the precursor that obtains coating layer coats ZrB ₂The composite granule of powder; Be taken up in order of priority with deionized water and this composite granule of absolute ethanol washing three times and once, with its 80 ℃ of oven dry, 500 ℃ of calcinings have just obtained Al again ₂O ₃And Y ₂O ₃The common ZrB that coats ₂The covered ZrB of powder granule ₂Composite granule.Covered ZrB ₂The coating thickness of composite granule is approximately 40nm, densification and even.

Claims (2)

1. covered ZrB ₂The preparation method of composite granule is characterized in that it comprises the steps:

1). with ZrB ₂Powder and water restrain by 1: the mixed of 50-1000 milliliter stirs, and obtains ZrB ₂The slurry of powder and water;

2). add salts solution in slurry, constant temperature stirs in 10～100 ℃; Wherein the add-on of salts solution is pressed ZrB ₂Powder: salts solution=1 gram: the ratio of 50-1000 milliliter adds, described salts solution is can produce sedimentary material in the solution of hydroxide ion is arranged, and is specially aluminum nitrate, Tai-Ace S 150, aluminum chloride, Yttrium trinitrate, Yttrium trichloride, yttrium sulfate or hypochlorous acid zirconium; The concentration of salts solution is 0.001-30mol/L; Adding the pH value simultaneously in slurry is the precipitation agent of 8-12, and the add-on of precipitation agent is to make the pH value of slurry remain 7-11.5, with the stirring that agitator does not stop, after salts solution dropwises, continues to stir 0.5～6 hour, and the precursor that obtains coating layer coats ZrB ₂The composite granule of powder; The material of described precipitation agent in the aqueous solution, there being hydroxide ion to produce;

3). with step 2) washing of the composite granule that obtains, in 80～150 ℃ of dryings, 300～700 ℃ of calcinings, product.

2. covered ZrB according to claim 1 ₂The preparation method of composite granule is characterized in that: the described material that has hydroxide ion to produce in the aqueous solution is ammoniacal liquor, urea or sodium hydroxide.

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