CN103011821B - Preparation method of h-BN/TiC machinable ceramics - Google Patents

Abstract

The invention relates to a preparation method of h-BN/TiC machinable ceramics, which is characterized by performing cold isostatic compaction on an h-BN coated TiC ceramic powder body, then performing hot compaction, and firing to obtain the h-BN/TiC machinable ceramics. The preparation method comprises the following steps: proportionally mixing boric acid and urea with ethanol in a closed container, thus preparing an esterification solution; then, adding a TiC ceramic powder body into the esterification solution, thus preparing ceramic slurry; preparing the ceramic slurry into a coated TiC powder body through a spray granulator; nitridizing the coated TiC powder body to obtain the h-BN coated TiC ceramic powder body; performing isostatic compaction on the h-BN coated TiC ceramic powder body to obtain a lamellar green body; and performing hot compaction under nitrogen atmosphere, and firing to obtain the h-BN/TiC machinable ceramics. The machinable ceramics prepared by the invention are uniform in h-BN phase distribution, controllable in content and fine in machinability, mechanical properties and thermal properties.

Description

A kind of preparation method of h-BN/TiC processable ceramic

Technical field

The present invention relates to a kind of h-BN/TiC processable ceramic, belong to ceramics processing field.

Background technology

Stupalith has many good performances, still, because stupalith hardness is large, while preparing precise measure ceramic component, only has by diamond abrasive wheel grinding, and manufacturing cost is very high.So people are finding a kind of method always, can meet basic mechanical performance requirement and can carry out again mechanical workout and obtain the method for precise measure ceramic component.The nineties in 20th century, the people such as Japanese scholars Niihara adopt Si ₃n ₄the coated h-BN of particle prepares the high processable ceramic parts of intensity, for a new way has been opened up in the preparation of high-performance processable ceramic parts; 2002, Li Yongli etc. were at " the Al that nanometer BN is coated ₂o ₃the preparation of composite powder and sintering character research thereof " the middle analytical reagent CO (N that adopts ₂) ₂and H ₃bO ₃mix with mol ratio 1:4, after fully grinding in mortar, with high-purity Al ₂o ₃(median size 03 μ m) puts into plastic tank take dehydrated alcohol as medium to powder together, uses aluminum oxide abrading-ball, and then wet-milling batch mixing dries (stirring) simultaneously, then ball milling, under hydrogen atmosphere, makes Al ₂o ₃-h-BN processable ceramic; The Dong Yan tinkling of pieces of jade in 2004 etc. are at " TiB ₂the preparation technology of one BN complex phase ceramic and performance study " in by TiB ₂, BN and Ni powder weigh by a certain percentage, respectively with different mixing method batch mixings, by mixed slurry dried and screened, and uniform compound packed in the graphite jig that scribbles BN, be placed in plasma discharge hot pressing furnace and carry out sintering in the protection of Ar gas and prepare TiB ₂-h-BN processable ceramic parts; 2009, Zhang Juxian adopted boric acid and urea and AlN powder to be blended under nitrogen atmosphere and fires and make AlN-h-BN processable ceramic in " low-dielectric loss AIN pottery and the research of BN-AIN base ceramic material ".In above-mentioned system except Si ₃n ₄the bending strength of-h-BN processable ceramic can reach beyond 950MPa., as TiB ₂-h-BN, the anti-intensity of the processable ceramics such as AlN-h-BN also only has 154 MPa. left and right.Therefore adopt the bending strength of processable ceramics material prepared by common mixing, chemical method h-BN coating technology lower.

Summary of the invention

The object of the present invention is to provide and a kind ofly can overcome above-mentioned defect, realize and prepare the more preparation method of high strength h-BN/TiC processable ceramic.Its technical scheme is:

A preparation method for h-BN/TiC processable ceramic, adopts the coated TiC ceramic powder hot pressing after cold isostatic compaction of h-BN to burn till h-BN/TiC processable ceramic, and concrete grammar comprises the following steps:

The first step: by boric acid: the ratio of urea take weight ratio as 2:1 evenly mixed, and additional 30 ~ 60% ethanol 50 ~ 90 ℃ of heat treated in encloses container stir after 10 ~ 24 hours again makes esterification solution for 10 ~ 30 minutes;

Second step: the TiC ceramic powder 40 ~ 70% that is 0.1 ~ 2 μ m by granularity joins ball milling in 30 ~ 60% above-mentioned esterification solution and makes ceramic size, then by sponging granulator, above-mentioned ceramic size is made to the coated TiC powder that diameter is 0.01 ~ 0.5mm, be that nitrogen atmosphere nitrogenize in 600 ~ 1000 ℃ × 30 ~ 60 minutes obtains the coated TiC ceramic powder of h-BN by above-mentioned coated TiC powder in temperature, coated h-BN TiC ceramic powder is made to 60 × 10 ~ 20mm flake shaped base substrate through isostatic cool pressing under the pressure of 100 ~ 200MPa., then under 1700 ~ 1850 ℃ × 30 ~ 180 minutes nitrogen atmospheres, hot pressing 5 ~ 100MPa. is fired into h-BN/TiC processable ceramic.

Compared with prior art, its advantage is in the present invention:

1, the present invention produces h-BN/TiC processable ceramic uniform microstructure, and intensity is high, and global reliability is high;

2, can form at TiC grain surface the h-BN layer of even thickness by this cladding process, and the thickness of h-BN layer is controlled, the bending strength of prepared h-BN/TiC processable ceramic improves 1 times compared with mixing, chemical method;

3, h-BN/TiC processable ceramic has good antioxidant property, mechanical property and thermal property.

Embodiment

embodiment 1

The first step: by boric acid: the ratio of urea take weight ratio as 2:1 evenly mixed additional 30% ethanol 50 ℃ of heat treated in encloses container and stirred after 24 hours again and makes esterification solution for 30 minutes;

Second step: the TiC ceramic powder 70% that is 0.1 μ m by granularity joins in 30% esterification solution and makes ceramic size; then by sponging granulator, above-mentioned ceramic size is made to the coated TiC powder that diameter is 0.5mm; be that nitrogen atmosphere nitrogenize in 600 ℃ × 30 minutes obtains the coated TiC ceramic powder of h-BN by above-mentioned coated TiC powder in temperature; coated h-BN TiC ceramic powder is pressed into 60 × 10mm flake shaped base substrate at the inferior static pressure of pressure of 100MPa., and then under 1700 ℃ × 30 minutes nitrogen atmospheres, hot pressing 5MPa. is fired into h-BN/TiC processable ceramic.

The purity of testing proportion material used is technical pure, and the bending strength of the h-BN/TiC processable ceramic obtaining is 344MPa..

embodiment 2

The first step: by boric acid: the ratio of urea take weight ratio as 2:1 evenly mixed additional 45% ethanol 70 ℃ of heat treated in encloses container and stirred after 16 hours again and makes esterification solution for 20 minutes;

Second step: the TiC ceramic powder 55% that is 1 μ m by granularity joins in 45% esterification solution and makes ceramic size; then by sponging granulator, above-mentioned ceramic size is made to the coated TiC powder that diameter is 0.2mm; be that nitrogen atmosphere nitrogenize in 800 ℃ × 45 minutes obtains the coated TiC ceramic powder of h-BN by above-mentioned coated TiC powder in temperature; coated h-BN TiC ceramic powder is pressed into 60 × 15mm flake shaped base substrate at the inferior static pressure of pressure of 150MPa., and then under 1800 ℃ × 105 minutes nitrogen atmospheres, hot pressing 50MPa. is fired into h-BN/TiC processable ceramic.

The purity of testing proportion material used is technical pure, and the bending strength of the h-BN/TiC processable ceramic obtaining is 360MPa..

embodiment 3

The first step: by boric acid: the ratio of urea take weight ratio as 2:1 evenly mixed additional 60% ethanol 90 ℃ of heat treated in encloses container and stirred after 10 hours again and makes esterification solution for 10 minutes;

Second step: the TiC ceramic powder 40% that is 2 μ m by granularity joins in 60% esterification solution and makes ceramic size; then by sponging granulator, above-mentioned ceramic size is made to the coated TiC powder that diameter is 0.01mm; be that nitrogen atmosphere nitrogenize in 1000 ℃ × 60 minutes obtains the coated TiC ceramic powder of h-BN by above-mentioned coated TiC powder in temperature; coated h-BN TiC ceramic powder is pressed into 60 × 20mm flake shaped base substrate at the inferior static pressure of pressure of 200MPa., and then under 1850 ℃ × 180 minutes nitrogen atmospheres, hot pressing 100MPa. is fired into h-BN/TiC processable ceramic.

The purity of testing proportion material used is technical pure, and the bending strength of the h-BN/TiC processable ceramic obtaining is 289MPa..

Claims (1)

1. a preparation method for h-BN/TiC processable ceramic, is characterized in that: adopt the coated TiC ceramic powder hot pressing after cold isostatic compaction of h-BN to burn till h-BN/TiC processable ceramic, concrete grammar comprises the following steps:

The first step: by boric acid: the ratio of urea take weight ratio as 2:1 evenly mixed, and additional 30 ~ 60% ethanol 50 ~ 90 ℃ of heat treated in encloses container stir after 10 ~ 24 hours again makes esterification solution for 10 ~ 30 minutes;

Second step: the TiC ceramic powder 40 ~ 70% that is 0.1 ~ 2 μ m by granularity joins ball milling in 30 ~ 60% above-mentioned esterification solution and makes ceramic size, then by sponging granulator, above-mentioned ceramic size is made to the coated TiC powder that diameter is 0.01 ~ 0.5mm, be that nitrogen atmosphere nitrogenize in 600 ~ 1000 ℃ × 30 ~ 60 minutes obtains the coated TiC ceramic powder of h-BN by above-mentioned coated TiC powder in temperature, coated h-BN TiC ceramic powder is made to 60 × 10 ~ 20mm flake shaped base substrate through isostatic cool pressing under the pressure of 100 ~ 200MPa., then under 1700 ~ 1850 ℃ × 30 ~ 180 minutes nitrogen atmospheres, hot pressing 5 ~ 100MPa. is fired into h-BN/TiC processable ceramic.