CN103641456A - High-strength nano composite ceramic material and preparation method thereof - Google Patents
High-strength nano composite ceramic material and preparation method thereof Download PDFInfo
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Abstract
The invention relates to the technical field of ceramic materials, particularly a high-strength nano composite ceramic material which is characterized by comprising the following components in percentage by weight: 2.5-5 parts of nano ZrO2, 40-45 parts of submicro Al2O3, 30-40 parts of nano TiC, 0.5-4 parts of nano BN, 1-4 parts of nano B4C and the balance of nano MgO. The nano or submicro material is compounded with the nano titanium carbide (TiC), nano boron nitride (BN) and nano boron carbide (B4C) to obtain the high-strength nano composite ceramic material; and the high-strength nano composite ceramic material is compounded with the zirconium oxide and aluminum oxide to obtain the ceramic material. The nano composite ceramic material has the advantages of high hardness, high strength, high fracture toughness, high temperature resistance and the like, is suitable for manufacturing and processing of high-performance products in ceramic technique, and is especially suitable for manufacturing and processing high-strength cutters.
Description
Technical field
The present invention relates to technical field of ceramic material, more specifically, relate to a kind of high-strength nano composite ceramic material and preparation method thereof.
Background technology
Composite ceramic material has that hardness is high, wear resistance good, thermo-chemical stability is strong, fusing point high, is specially adapted to make process tool.With the cutter of composite ceramic material manufacture, at high temperature still can carry out high speed cutting, little with the avidity of the metals such as iron and steel, frictional coefficient is low, anti stick and anti-diffusibility are strong, during cutting, be difficult for sticky cutter and produce built-up edge, the machined surface quality of workpiece, these features make composite ceramic cutting tool be particularly suitable for processing various difficult-to-machine materials.
Base titanium carbonitride (Ti(C, N)) at the beginning of the 70's of twentieth century, grow up, take Ti(C, N) as main hard phase with to take nickel, molybdenum be that Binder Phase forms, the NEW TYPES OF TOOL MATERIALS that adopts powder metallurgical technique to be prepared from.Base titanium carbonitride has higher hardness, good wear resistance, desirable anti-crescent hollow abrasion ability, good resistance of oxidation and chemical stability.
Cutter is in cutting process, and the forward and backward knife face of cutter constantly contacts with workpiece with smear metal, and violent friction occurs, and zone of action is in high temperature, high pressure conditions.The friction and wear occurring on cutter can cause tool damage and lose efficacy, and cutting cannot be carried out; The violent friction occurring on workpiece can make machined surface quality worsen.
Summary of the invention
The present invention is intended to solve the problems of the technologies described above at least to a certain extent.
Primary and foremost purpose of the present invention is to provide a kind of high-strength nano composite ceramic material, and this stupalith hardness is high, good toughness, and has good high-temperature stability.
A further object of the present invention is to provide a kind of preparation method of high-strength nano composite ceramic material.
For solving the problems of the technologies described above, the technical solution used in the present invention is:
A kind of high-strength nano composite ceramic material is provided, comprises by weight percentage following component: nanometer ZrO
22.5 ~ 5 parts, submicron Al
2o
340 ~ 45 parts, 30 ~ 40 parts of nano TiCs, 0.5 ~ 4 part of nanometer BN and nanometer B
41 ~ 4 part of C, surplus is nano-MgO.
Zirconium white (ZrO
2) material itself has the good physical and chemical performances such as high rigidity, high strength, high tenacity, high wear resistance and chemical resistance, obtains application widely in the various fields such as pottery, refractory materials, machinery, electronics, optics, opticfiber communication, clock and watch ornaments, aerospace, biology, chemistry; And aluminum oxide (Al
2o
3) itself also possess that physical strength is high, hardness is large, high-frequency dielectric loss is little, high-temperature insulation resistance is high, chemical resistance and the good comprehensive technical performance such as thermal conductivity is good.Zirconium white and aluminum oxide all can be used on ceramic field, but its simple compound composition can not obtain well behaved stupalith.
On the basis of zirconium white of the present invention and aluminum oxide performance, adopt its nanometer or submicron order material, compound interpolation nano titanium carbide (TiC), nm-class boron nitride (BN) and nano boron carbide (B
4c) obtain high-strength nano composite ceramic material, titanium carbide has high rigidity, high-melting-point and anti abrasive performance, boron nitride is high temperature resistant, norbide fragility is low and wear-resisting, through evidence, the stupalith that above-mentioned materials and zirconium white and alumina composite are obtained, be that this nanocomposite ceramic material of the present invention has high rigidity, high strength, high fracture toughness and the premium properties such as high temperature resistant, be applicable to requiring in ceramic process the manufacture processing of high performance product, be specially adapted to make the high-intensity cutter of processing.
Preferably, comprise by weight percentage following component: nanometer ZrO
24.5 parts, submicron Al
2o
345 parts, 38 parts of nano TiCs, 4 parts of nanometer BN and nanometer B
44 parts of C, surplus is nano-MgO.
As improvement, also comprise by weight percentage 1.5 ~ 4.5 parts of solid lubricants.Solid lubricant refers to separate the solid material of the low shearing resistance of one deck on friction pair antithesis surface.For this class material, except requiring to have low shearing resistance, and also should possess stronger binding power between substrate surface, that is to say, load is born by substrate, and relative movement occurs in solid lubricant.In cutting process, the machined surface quality bringing for fear of violent friction worsens, and the situation of performance degradation can occur cutting fluid under the effect of high temperature, therefore add solid lubricant, addresses the above problem.
Alternatively, described solid lubricant is layered solid material, mineral compound, soft metal or high molecular polymer.
Alternatively, layered solid material is graphite or molybdenumdisulphide; Described mineral compound is lithium fluoride, Calcium Fluoride (Fluorspan), plumbous oxide or lead sulfide; Described soft metal is lead, indium, tin, gold and silver or cadmium; Described high molecular polymer is nylon, tetrafluoroethylene or polyimide, can be also matrix material.
Preferably, described solid lubricant is submicron molybdenumdisulphide.Molybdenumdisulphide (MoS
2) pulvis is to be made through chemical purification by natural brightness concentrated molybdenum ore, its dispersiveness is high, purity is high, adsorptivity is strong, look blackly is slightly with silver gray, have metalluster, touch have a soapy feeling, water insoluble, because its bonding strength is low, be easy to along cleave plane slippage, so shearing resistance is little, rubbing factor is little.
The present invention also provides a kind of preparation method of the composite ceramic material of high-strength nano as mentioned above, comprises the following steps:
S1. prepare burden: prepare burden by weight percentage: nanometer ZrO
22.5 ~ 5 parts, submicron Al
2o
340 ~ 45 parts, 30 ~ 40 parts of nano TiCs, 0.5 ~ 4 part of nanometer BN and nanometer B
41 ~ 4 part of C, surplus is nano-MgO;
S2. dispersing nanoparticles: the batching after weighing is mixed with to suspension, and then ultrasonic agitation is to evenly;
S3. each particle of step S2 is compound, on ball mill, ball milling mixes, and through vacuum-drying, obtains raw material powder;
S4. the raw material powder mixing is packed in graphite jig, adopt hot-pressing sintering technique to be prepared, obtain nanocomposite ceramic material.
Preferably, in step S4, sintering temperature is 1500 ~ 1700 ℃, soaking time 40min.
Compared with prior art, the invention has the beneficial effects as follows:
High-strength nano composite ceramic material of the present invention, on the basis of zirconium white and the performance of aluminum oxide own, adopts its nanometer or submicron order material, compound interpolation nano titanium carbide (TiC), nm-class boron nitride (BN) and nano boron carbide (B
4c) obtain high-strength nano composite ceramic material, the stupalith that above-mentioned materials and zirconium white and alumina composite are obtained, be that this nanocomposite ceramic material of the present invention has high rigidity, high strength, high fracture toughness and the premium properties such as high temperature resistant, be applicable to requiring in ceramic process the manufacture processing of high performance product, be specially adapted to make the high-intensity cutter of processing.
Embodiment
Below in conjunction with embodiment, the present invention is further illustrated.
Embodiment 1
4.5 parts of nanometer ZrO
2, 45 parts of submicron Al
2o
3, 38 parts of nano TiCs, 4 parts of nanometer BN and 4 parts of nanometer B
4c, 2.5 parts of submicron MoS
2, surplus is nano-MgO.
After tested, the mechanical property of the high-strength nano composite ceramic material that the present embodiment makes is: hardness HV17.7 ~ 18.3Gpa, and bending strength is 660 ~ 720Mpa, fracture toughness property is 6.8 ~ 8.5MPam
1/2.
Embodiment 2
2.5 parts of nanometer ZrO
2, 45 parts of submicron Al
2o
3, 35 parts of nano TiCs, 3 parts of nanometer BN and 4 parts of nanometer B
4c, 1.5 parts of submicron PbO, surplus is nano-MgO.
After tested, the mechanical property of the high-strength nano composite ceramic material that the present embodiment makes is: hardness HV13.4 ~ 16.3Gpa, and bending strength is 630 ~ 710Mpa, fracture toughness property is 5.8 ~ 7.5MPam
1/2.
Embodiment 3
5 parts of nanometer ZrO
2, 40 parts of submicron Al
2o
3, 32 parts of nano TiCs, 2 parts of nanometer BN and 1 part of nanometer B
4c, 2.5 parts of submicron Ag, surplus is nano-MgO.
After tested, the mechanical property of the high-strength nano composite ceramic material that the present embodiment makes is: hardness HV15.7 ~ 17.3Gpa, and bending strength is 620 ~ 700Mpa, fracture toughness property is 6.5 ~ 8.0MPam
1/2.
Embodiment 4
3.5 parts of nanometer ZrO
2, 40 parts of submicron Al
2o
3, 30 parts of nano TiCs, 1 part of nanometer BN and B
42 parts of nanometers of C, 3.5 parts of polyimide, surplus is nano-MgO.
After tested, the mechanical property of the high-strength nano composite ceramic material that the present embodiment makes is: hardness HV16.5 ~ 16.8Gpa, and bending strength is 640 ~ 680Mpa, fracture toughness property is 5.9 ~ 7.9MPam
1/2.
Embodiment 5
3 parts of nanometer ZrO
2, 43 parts of submicron Al
2o
3, 40 parts of nano TiCs, 0.5 part of nanometer BN and 3 parts of nanometer B
4c, 4.5 parts of graphite, surplus is nano-MgO.
After tested, the mechanical property of the high-strength nano composite ceramic material that the present embodiment makes is: hardness HV13.9 ~ 15.9Gpa, and bending strength is 640 ~ 700Mpa, fracture toughness property is 6.0 ~ 8.1MPam
1/2.
Embodiment 6
The high-strength nano composite ceramic material of above-mentioned arbitrary embodiment can be made by following preparation method, specifically comprises the following steps:
S1. prepare burden.Prepare burden by weight percentage: nanometer ZrO
22.5 ~ 5 parts, submicron Al
2o
340 ~ 45 parts, 30 ~ 40 parts of nano TiCs, 0.5 ~ 4 part of nanometer BN and nanometer B
41 ~ 4 part of C, surplus is nano-MgO.
S2. dispersing nanoparticles.While realizing this step, the polyoxyethylene glycol (PEG) of can take is dispersion agent, quality is about 1%, first the nano material after weighing is slowly added in dehydrated alcohol, stir while adding, be mixed with volume fraction and be 2% suspension, dispersion agent is added in the suspension of nano material, more than ultrasonic agitation 30min, make suspension even, obtain the suspension of good dispersion property;
S3. ball milling dry mixed.Each particle of step S2 is compound, and on ball mill, ball milling mixes it in approximately 48 hours, through vacuum-drying, 120 mesh sieves, sieve, and the raw material powder that obtains mixing;
S4. sintering.The raw material powder mixing is packed in graphite jig, adopt hot-pressing sintering technique to be prepared, sintering temperature is 1500 ~ 1700 ℃, and soaking time 40min, obtains nanocomposite ceramic material.
Obviously, the above embodiment of the present invention is only for example of the present invention is clearly described, and is not the restriction to embodiments of the present invention.For those of ordinary skill in the field, can also make other changes in different forms on the basis of the above description.Here exhaustive without also giving all embodiments.All any modifications of doing within the spirit and principles in the present invention, be equal to and replace and improvement etc., within all should being included in the protection domain of the claims in the present invention.
Claims (8)
1. a high-strength nano composite ceramic material, is characterized in that, comprises by weight percentage following component: nanometer ZrO
22.5 ~ 5 parts, submicron Al
2o
340 ~ 45 parts, 30 ~ 40 parts of nano TiCs, 0.5 ~ 4 part of nanometer BN and nanometer B
41 ~ 4 part of C, surplus is nano-MgO.
2. high-strength nano composite ceramic material according to claim 1, is characterized in that, comprises by weight percentage following component: nanometer ZrO
24.5 parts, submicron Al
2o
345 parts, 38 parts of nano TiCs, 4 parts of nanometer BN and nanometer B
44 parts of C, surplus is nano-MgO.
3. high-strength nano composite ceramic material according to claim 1 and 2, is characterized in that, also comprises by weight percentage 1.5 ~ 4.5 parts of solid lubricants.
4. high-strength nano composite ceramic material according to claim 3, is characterized in that, described solid lubricant is layered solid material, mineral compound, soft metal or high molecular polymer.
5. high-strength nano composite ceramic material according to claim 4, is characterized in that, layered solid material is graphite or molybdenumdisulphide; Described mineral compound is lithium fluoride, Calcium Fluoride (Fluorspan), plumbous oxide or lead sulfide; Described soft metal is lead, indium, tin, gold and silver or cadmium; Described high molecular polymer is nylon, tetrafluoroethylene or polyimide.
6. high-strength nano composite ceramic material according to claim 3, is characterized in that, described solid lubricant is submicron molybdenumdisulphide.
7. a preparation method for high-strength nano composite ceramic material as described in claim 1 to 5 any one, is characterized in that, comprises the following steps:
S1. prepare burden: prepare burden by weight percentage: nanometer ZrO
22.5 ~ 5 parts, submicron Al
2o
340 ~ 45 parts, 30 ~ 40 parts of nano TiCs, 0.5 ~ 4 part of nanometer BN and nanometer B
41 ~ 4 part of C, surplus is nano-MgO;
S2. dispersing nanoparticles: the batching after weighing is mixed with to suspension, and then ultrasonic agitation is to evenly;
S3. each particle of step S2 is compound, on ball mill, ball milling mixes, and through vacuum-drying, obtains raw material powder;
S4. the raw material powder mixing is packed in graphite jig, adopt hot-pressing sintering technique to be prepared, obtain nanocomposite ceramic material.
8. preparation method according to claim 7, is characterized in that, in step S4, sintering temperature is 1500 ~ 1700 ℃, soaking time 40min.
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104311091A (en) * | 2014-09-30 | 2015-01-28 | 苏州博利迈新材料科技有限公司 | Rare-earth-doped nano ceramic material and preparation method thereof |
| CN104326749A (en) * | 2014-09-30 | 2015-02-04 | 苏州博利迈新材料科技有限公司 | High strength nanometer ceramic material and preparation method thereof |
| CN104403381A (en) * | 2015-01-07 | 2015-03-11 | 苏州大学 | Corrosion resistant ceramic paint and preparation method thereof |
| CN105130437A (en) * | 2015-09-01 | 2015-12-09 | 广西南宁智翠科技咨询有限公司 | High-hardness wear-resistant titanium carbide ceramic and preparation method thereof |
| CN105174962A (en) * | 2015-09-11 | 2015-12-23 | 杨洋 | High-strength high-temperature titanium ceramic and preparation method thereof |
| CN105174923A (en) * | 2015-09-02 | 2015-12-23 | 安徽万年针织有限公司 | Low temperature resistance ceramic eye containing molybdenum disulfide |
| CN105174969A (en) * | 2015-09-23 | 2015-12-23 | 杨洋 | High-hardness silicon nitride ceramic and preparing method thereof |
| CN105330293A (en) * | 2015-09-01 | 2016-02-17 | 广西南宁智翠科技咨询有限公司 | High-hardness and high-temperature resistance titanium carbide ceramic and preparation method thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1583660A (en) * | 2004-06-02 | 2005-02-23 | 山东大学 | Self-lubricating ceramic cutting bits |
| CN101857438A (en) * | 2010-05-25 | 2010-10-13 | 山东大学 | Method for preparing aluminum oxide-titanium carbide-zirconium oxide nanocomposite ceramic material |
-
2013
- 2013-12-12 CN CN201310672562.6A patent/CN103641456B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1583660A (en) * | 2004-06-02 | 2005-02-23 | 山东大学 | Self-lubricating ceramic cutting bits |
| CN101857438A (en) * | 2010-05-25 | 2010-10-13 | 山东大学 | Method for preparing aluminum oxide-titanium carbide-zirconium oxide nanocomposite ceramic material |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN104311091A (en) * | 2014-09-30 | 2015-01-28 | 苏州博利迈新材料科技有限公司 | Rare-earth-doped nano ceramic material and preparation method thereof |
| CN104326749A (en) * | 2014-09-30 | 2015-02-04 | 苏州博利迈新材料科技有限公司 | High strength nanometer ceramic material and preparation method thereof |
| CN104311091B (en) * | 2014-09-30 | 2016-05-18 | 苏州博利迈新材料科技有限公司 | A kind of rare earth mixing with nano ceramic material and preparation method thereof |
| CN104326749B (en) * | 2014-09-30 | 2016-08-17 | 深圳市四鼎华悦科技有限公司 | A kind of high strength nanophase ceramic material and preparation method thereof |
| CN104403381A (en) * | 2015-01-07 | 2015-03-11 | 苏州大学 | Corrosion resistant ceramic paint and preparation method thereof |
| CN104403381B (en) * | 2015-01-07 | 2017-06-16 | 苏州大学 | A kind of corrosion-resistant ceramic coating and preparation method thereof |
| CN105130437A (en) * | 2015-09-01 | 2015-12-09 | 广西南宁智翠科技咨询有限公司 | High-hardness wear-resistant titanium carbide ceramic and preparation method thereof |
| CN105330293A (en) * | 2015-09-01 | 2016-02-17 | 广西南宁智翠科技咨询有限公司 | High-hardness and high-temperature resistance titanium carbide ceramic and preparation method thereof |
| CN105174923A (en) * | 2015-09-02 | 2015-12-23 | 安徽万年针织有限公司 | Low temperature resistance ceramic eye containing molybdenum disulfide |
| CN105174962A (en) * | 2015-09-11 | 2015-12-23 | 杨洋 | High-strength high-temperature titanium ceramic and preparation method thereof |
| CN105174969A (en) * | 2015-09-23 | 2015-12-23 | 杨洋 | High-hardness silicon nitride ceramic and preparing method thereof |
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Effective date of registration: 20160122 Address after: 521000, 15, Chaozhou, Guangdong province Xiangqiao District Road North Yang Yang Lane No. 403 Applicant after: Chen Ming Applicant after: Lin Hao Address before: 521000, Chaozhou, Guangdong province Dongxiang Maple Creek Village Applicant before: Liu Xiuduan |
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