CN101591174A - A kind of preparation method of silicon nitride ceramics and the silicon nitride ceramics for preparing by this method - Google Patents
A kind of preparation method of silicon nitride ceramics and the silicon nitride ceramics for preparing by this method Download PDFInfo
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- CN101591174A CN101591174A CNA2008100675482A CN200810067548A CN101591174A CN 101591174 A CN101591174 A CN 101591174A CN A2008100675482 A CNA2008100675482 A CN A2008100675482A CN 200810067548 A CN200810067548 A CN 200810067548A CN 101591174 A CN101591174 A CN 101591174A
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Abstract
A kind of preparation method of silicon nitride ceramics comprises silicon nitride particle, sinter additives, caking agent mixed obtaining mixture, and described mixture injection molding is formed blank, to described blank carry out degreasing, sintering makes described silicon nitride ceramics.The surfaceness of the silicon nitride ceramics by method for preparing has obtained remarkable reduction, and density, room temperature flexural strength and high temperature bend strength all be improved, and satisfies various requirements to the demanding complex parts of surfaceness.
Description
[technical field]
The present invention relates to a kind of preparation method of silicon nitride ceramics and the silicon nitride ceramics for preparing by this method.
[background technology]
Silicon nitride ceramics is a kind of with α-Si
3N
4Or β-Si
3N
4Be the special ceramic material of principal crystalline phase, it has a series of good character, as high strength, high tenacity, high heat conduction, high temperature creep-resisting excellent property, self-lubricating ability that wear resistance is good, good.Original advantage is arranged being used to make on high temperature blade, high-temperature valve, high temperature nozzle, bearing, the cutting tool.
Traditional method for preparing silicon nitride ceramic material comprises: carry out dry-pressing, injection moulding or isostatic pressing earlier, degreasing again, carry out pressureless sintering or pressure sintering at 1600 ℃-1900 ℃ at last, sintering atmosphere is generally nitrogen atmosphere, and silicon nitride decomposes gasification in this sintering range to avoid.
Because the hardness of silicon nitride ceramic material is big, the machining difficulty is difficult to use in the preparation complex parts, and the component that adopt above-mentioned traditional method to prepare are more because of burr, and the polishing difficulty causes the surfaceness height, is difficult to be extended on the precise part and uses.
For satisfying the requirement of complex parts surfaceness, usually ceramic surface to be handled, treatment process comprises mechanical polishing, but above-mentioned processing complicated operation, and should processing can cause the increase of production cost, the defect ware rate also can raise.
[summary of the invention]
The present invention provides a kind of easy to operate in order to overcome the problems referred to above that prior art exists when preparing baroque silicon nitride ceramic material, can reduce the method for silicon nitride ceramic material surfaceness.
The inventor finds to use ceramic injection forming to make silicon nitride ceramic material can directly obtain lower surfaceness (Ra≤1 μ m, surfaceness disclosed herein all obtains according to GB/T 13841-1992 test), need not to carry out in addition surface treatment, reduce production cost, also improved good article rate simultaneously.
The invention provides a kind of preparation method of silicon nitride ceramic material, this method comprises silicon nitride particle, sinter additives, caking agent mixed and obtains mixture, described mixture injection molding is formed blank, to described blank carry out degreasing, sintering makes described silicon nitride ceramic material.
With described silicon nitride particle and sinter additives gross weight is benchmark, and described silicon nitride particle content is 80-95wt%.
Described silicon nitride particle aspect ratio index is 1-2.5, and the silicon nitride particle median size is not more than 1 μ m.
Described binding agent contains paraffin, high molecular polymer and organic acid.Described degreasing is solvent degreasing and/or hot degreasing.
Surface roughness Ra≤the 1um of the silicon nitride ceramics that makes by method provided by the invention reaches the requirement (Ra≤1um) of general complicated precision parts corase grind rear surface roughness.
In addition, the unexpected discovery of contriver has also increased by the density of the silicon nitride ceramic material of method preparation provided by the invention.Density is 2.97-3.14g/cm when adopting 20 ℃ of silicon nitride ceramic materials that traditional method makes
3, silicon nitride (Si
3N
4) theoretical density is 3.44g/cm 20 ℃ times
3, (in the process of preparation silicon nitride ceramic material, need in the silicon nitride particle raw material, add sinter additives, but the density influence of the stupalith that the sinter additives that adds makes sintering is very little, this influence can be ignored in the art.The density of silicon nitride ceramic material all obtains according to GB/T 2413-1981 test among the present invention).
Silicon nitride ceramic material by method preparation disclosed by the invention is compared with the silicon nitride ceramic material of traditional method preparation, density significantly increases, surfaceness reduces, surfaceness as the silicon nitride ceramics A1-A5 of embodiment 1-5 preparation is more much lower than CA1-CA2, density is big than CA1, CA2 also, and room temperature flexural strength and the high temperature bend strength of silicon nitride ceramics A1-A5 all are improved.
[embodiment]
The invention provides a kind of preparation method of silicon nitride ceramics, this method comprises silicon nitride particle, sinter additives, caking agent mixed and obtains mixture, described mixture injection molding is formed blank, to described blank carry out degreasing, sintering makes described silicon nitride ceramics.
Silicon nitride ceramics is a kind of by α-Si
3N
4And β-Si
3N
4The special material of two phase composites.Wherein, α-Si
3N
4Particle is similar to spherical, and β-Si
3N
4Particle is a needle-like.In silicon nitride ceramic material, with α-Si
3N
4Be principal phase, β-Si
3N
4Be scattered in the principal phase, can play reinforcement and increase hard effect.But β-Si in the material
3N
4Too high levels can cause the strength of materials and hardness all to descend.
According to the present invention, described silicon nitride particle is by α-Si
3N
4And β-Si
3N
4Two phase composites, wherein α-Si
3N
4With β-Si
3N
4Content can change within the specific limits, be benchmark with the silicon nitride particle total amount under the preferable case, α-Si
3N
4Content is 60-98wt%, more preferably 80-97wt%.Described silicon nitride particle can be commercially available, as the Si of novel material Science and Technology Ltd. of the section production that rubs
3N
4Powder, α-Si
3N
4Content is 96wt%.The inventor found through experiments, as α-Si
3N
4Content is in above-mentioned scope the time, and the density of the silicon nitride ceramic material that sintering obtains is bigger.
Described silicon nitride particle aspect ratio index is 1-2.5, is preferably 1; Described silicon nitride particle median size is not more than 1 μ m.This silicon nitride particle can be commercially available, as the submicron order silicon nitride of novel material Science and Technology Ltd. of the section production that rubs.Described aspect ratio implication is that those skilled in the art is known, and promptly the maximum dimension of particulate is divided by minimum dimension, and the aspect ratio of spheroidal particle is 1.Surfaceness is meant the comprehensive evaluation of the microcosmic geometries characteristic of the small peak valley roughness on less spacing that material surface has.Surfaceness is represented with Ra usually.
The present inventor finds through a large amount of tests, when silicon nitride particle aspect ratio index is 1-2.5, the density of the silicon nitride ceramic material that sintering obtains is bigger than density of the prior art, and simultaneously, the surfaceness of the silicon nitride ceramic material that makes has obtained further raising.Silicon nitride particle aspect ratio index is preferably 1, and when silicon nitride particle aspect ratio index was 1, when being spherical silicon nitride particle, the density of the silicon nitride ceramic material that spherical silicon nitride particle sintering obtains was more near 3.44g/cm
3Theoretical value, and its surfaceness is minimum.When silicon nitride particle aspect ratio index greater than 2.5 the time because the influence of particle form, the surfaceness of the silicon nitride ceramic material that makes increases.
Described silicon nitride particle is preferably median size and is not more than 1 μ m.The particle median size is big more, is unfavorable for the dense sintering of particulate material more, the density of the silicon nitride ceramic material that influence obtains.
The sinter additives that adopts among the present invention is a sinter additives well known in the art, and one or more in optional autoxidation magnesium, aluminum oxide, the rare earth oxide, described rare earth oxide are any one in yttrium oxide, gadolinium sesquioxide, the ytterbium oxide.Under the preferable case, sinter additives is the mixture of aluminum oxide and rare earth oxide, more preferably the mixture of aluminum oxide and yttrium oxide; Mixture total weight amount with aluminum oxide and rare earth oxide is a benchmark, and alumina content is 20-90wt%.
According to the present invention, be benchmark with described silicon nitride particle and sinter additives gross weight, described silicon nitride particle content is 80-95wt%, is preferably 88-92wt%.
Disclosed binding agent contains paraffin, high molecular polymer and organic acid among the present invention.
Described paraffin can be commercially available, as the 56# paraffin of Jiahe, Shanghai City trade Co., Ltd production; Described high molecular polymer can be selected for use: one or more in ethylene-vinyl acetate copolymer, high density polyethylene(HDPE), polypropylene, the polystyrene; Be preferably the mixture of ethylene-vinyl acetate copolymer and high density polyethylene(HDPE), the weight-average molecular weight of described ethylene-vinyl acetate copolymer is 2000-20000, vinyl acetate between to for plastic accounts for the 10-25wt% of ethylene-vinyl acetate copolymer, and the density of described high density polyethylene(HDPE) is 0.94-0.98g/cm
3Wherein, be benchmark with the mixture total weight amount of ethylene-vinyl acetate copolymer and high density polyethylene(HDPE), ethylene-vinyl acetate copolymer content is 20-50wt%.Described high molecular polymer can be commercially available, as the high density polyethylene(HDPE) 2100J of Sinopec Yangzi Petrochemical Co., Ltd production; Described organic acid can be selected at least a in oleic acid, stearic acid or the stearate for use, is preferably oleic acid and/or stearic acid; Described organic acid also can be commercially available, as the oleic acid of Xinghua City great achievement Vegetable oil lipoprotein factory production.
Among the present invention, the gross weight of described binding agent is a benchmark, and the content of paraffin is 30-60wt%, and the content of high molecular polymer is 30-60wt%, and organic acid content is 5-15wt%.Be preferably, the content of paraffin is 40-60wt%, and the content of ethylene-vinyl acetate copolymer is 10-30wt%, and the content of high density polyethylene(HDPE) is 10-30wt%, and organic acid content is 8-12wt%.It doesn't matter between the content of ethylene-vinyl acetate copolymer and high density polyethylene(HDPE), as long as the amount of the mixture of ethylene-vinyl acetate copolymer and high density polyethylene(HDPE) is in above-mentioned high molecular polymer content range.
The contriver found through experiments, and adopts binding agent easier getting rid of in skimming processes of above-mentioned composition, and the surfaceness of the silicon nitride ceramic material that obtains behind the sintering reduces, and density is improved.
Among the present invention, the content of described binding agent can change within a large range, under the preferable case, is benchmark with the gross weight of silicon nitride particle and sinter additives, and the content of described binding agent is 15-75wt%, more preferably 20-30wt%.
According to the present invention, the described method that silicon nitride particle, sinter additives and binding agent are mixed has no particular limits, as long as silicon nitride particle, sinter additives and binding agent are mixed, described blended condition comprises that mixing temperature is 130-180 ℃, mixing time is 1-5h, under the preferable case, described mixing temperature is 140-165 ℃, and mixing time is 2-4h.Can use high-speed mixer to carry out just mixing, use twin screw extruder to carry out banburying afterwards.Just mix used high-speed mixer and have no particular limits, can use the various mixing equipment of this area routine, as the high-speed mixer SHR-200A of Zhangjagang City's Colaesce machine works production; The used twin screw extruder of banburying has no particular limits, and can use the various banburying equipment of this area routine, as the twin screw extruder SJSZ45 of Zhangjagang City's Colaesce machine works production.
Among the present invention; mixed silicon nitride particle, sinter additives and binder mixtures are carried out broken method to be had no particular limits; can use the various granulating equipment of this area routine, as the tablets press HRSJL-150 of Sichuan China auspicious machinofacture company limited production.Broken back particulate size has no particular limits, as long as can meet the requirement of injection forming equipment.
According to the present invention, described injection molding method is conventionally known to one of skill in the art, for example, the particle after the fragmentation is packed in the injection moulding machine, is expelled in the mould with blank structure, and injection molding under the injection molding condition obtains blank afterwards.Described injection molding condition comprises that injection molding temperature is 140-180 ℃, injection molding pressure is 5-25MPa, the injection molding time can in very large range change, generally speaking, the injection molding time of single-piece sample is 2-10s, described injection molding equipment has no particular limits, and can use the injection molding equipment of various routines, moulds the ceramic injection forming machine that Science and Technology Ltd. produces as the special magnetic of Zhangjiagang times grace.
Among the present invention, described degreasing is solvent degreasing and/or hot degreasing.The condition of described solvent degreasing comprises that skimming temp is 40-65 ℃, and the insulation degreasing time is 5-20h, and under the preferable case, skimming temp is 45-55 ℃, and degreasing time is 8-20h.The solvent of described solvent degreasing is conventionally known to one of skill in the art, can be in gasoline, normal heptane, normal hexane, trieline, methylene dichloride, trichloromethane and the trichloroethane one or more, under the preferable case, described solvent is the less relatively gasoline of toxicity; Described solvent can be commercially available, as the methylene dichloride of the Shenzhen prosperous chemical industry of benefit group company limited production.
The condition of described hot degreasing can be the hot degreasing condition of routine, for example, hot skimming temp is 200-900 ℃, the time of hot degreasing is 3-20h, under the preferable case, described hot degreasing comprises three phases, and hot degreasing of fs is meant and is warming up to 200-350 ℃ in 10-40min, and keeps this temperature 1-5h; The hot degreasing of subordinate phase is meant and is warming up to 400-550 ℃ in 30-250min, and keeps this temperature 1-5h; Hot degreasing of phase III is meant and is warming up to 700-900 ℃ in 10-60min, and keeps this temperature 0.5-2h.
In order to prevent the silicon nitride oxidation when the hot degreasing in the blank, described hot degreasing is carried out under the neutral gas atmosphere of 50kPa-150kPa or vacuum environment, and wherein, described neutral gas can be one or more in neutral element gas and the nitrogen; The pressure of described vacuum environment is below the 0.2Pa.
According to the present invention, it is conventionally known to one of skill in the art under nitrogen environment the blank after the degreasing being carried out the agglomerating method, for example, is warmed up to sintering temperature 1500-1900 ℃, sintering time 0.5-6h, described nitrogen gas purity greater than 99.9%, the sintering ambient pressure is 60kPa-200kPa.
The present invention is further illustrated below by embodiment.
Embodiment 1
Present embodiment is used to illustrate the preparation method of silicon nitride ceramic material provided by the invention.
(1) 100 weight parts are contained 90wt% silicon nitride particle (silicon nitride particle that the novel material Science and Technology Ltd. of section that rubs produces, particle aspect ratio index is 2, median size is 1.5 μ m, α-Si
3N
4Content is 75wt%), sinter additives and 25 parts by weight of adhesive of 10wt% put into high-speed mixer (the high-speed mixer SHR-200A that Colaesce machine works in Zhangjagang City's produces) and mix, described blended temperature is 160 ℃, the blended time is 1h, subsequently the mixture that obtains is changed in the twin screw extruder (the twin screw extruder SJSZ45 that Colaesce machine works in Zhangjagang City's produces) and mix, the blended temperature is 160 ℃, and the blended time is 1h.
Described sinter additives is aluminum oxide and gadolinium sesquioxide, is benchmark with described sinter additives total amount, and alumina content is 50wt%.
With described binding agent total amount is benchmark, and described binding agent contains the paraffin of 75wt%, (density is 0.97g/cm to the high density polyethylene(HDPE) of 25wt%
3).
(2) will be in twin screw extruder mixed product broken in pulverizer, the particulate average particle diameter after the fragmentation is 2mm.Particle after the fragmentation is packed in the injection moulding machine (times grace special magnetic in Zhangjiagang is moulded the ceramic injection forming machine that Science and Technology Ltd. produces), be expelled in the mould with blank structure, injection molding afterwards, described injection molding condition comprises that injection molding temperature is 165 ℃, injection molding pressure is 10MPa, the injection molding time is 3s, obtains the blank that wall thickness is 5mm.
(3) blank that obtains is put into carried out solvent degreasing in the normal hexane, the condition of described solvent degreasing comprises that skimming temp is 50 ℃, degreasing time is 8h, afterwards the blank after the solvent degreasing is put in the debinding furnace, in 125kPa purity is to carry out hot degreasing under 99.9% the nitrogen atmosphere.
Described hot degreasing comprises three phases, and hot degreasing of fs is meant and is warming up to 300 ℃ in 20min, and keeps this temperature 4h; The hot degreasing of subordinate phase is meant and is warming up to 450 ℃ in 150min, and keeps this temperature 5h; Hot degreasing of phase III is meant and is warming up to 850 ℃ in 40min, and keeps this temperature 1h.
(4) blank after the degreasing is put into sintering in the sintering oven (powder metallurgy sintering furnace that Xiangtan City Gao Noboru power metallurgy equipment company limited produces), atmosphere in the stove is the high pure nitrogen of purity 99.99%, pressure remains 100kPa, in 700min, be warming up to 1650 ℃, sintering 5h obtains silicon nitride ceramic material goods A1.
Embodiment 2
Present embodiment is used to illustrate the preparation method of silicon nitride ceramic material provided by the invention.
The preparation method of silicon nitride ceramic material is with embodiment 1, and different is that the silicon nitride particle aspect ratio index that adopts is 1.51, and median size is 1 μ m.
Make silicon nitride ceramic material goods A2.
Embodiment 3
Present embodiment is used to illustrate the preparation method of silicon nitride ceramic material provided by the invention.
(1) 100 weight parts are contained 85wt% silicon nitride particle (silicon nitride particle that the novel material Science and Technology Ltd. of section that rubs produces, particle aspect ratio index is 1.5, median size is 1 μ m, α-Si
3N
4Content is 85wt%), the sinter additives of 15wt% puts into high-speed mixer with 35 parts by weight of adhesive and mixes, described blended temperature is 150 ℃, the blended time is 1h, subsequently the mixture that obtains is changed in the twin screw extruder and mix, the blended temperature is 150 ℃, and the blended time is 1h.
Described sinter additives is aluminum oxide and yttrium oxide, is benchmark with described sinter additives total amount, and alumina content is 30wt%;
With described binding agent total amount is benchmark, described binding agent contains the high density polyethylene(HDPE) of the paraffin of 55wt%, the ethylene-vinyl acetate copolymer of 18wt% (weight-average molecular weight is 10000, and vinyl acetate between to for plastic accounts for the 18wt% of ethylene-vinyl acetate copolymer), 14wt%, and (density is 0.97g/cm
3) and the oleic acid of 13wt%.
(2) will be in twin screw extruder mixed product broken in pulverizer, the particulate average particle diameter after the fragmentation is 2mm.Particle after the fragmentation is packed in the injection moulding machine, be expelled in the mould with blank structure injection molding afterwards, described injection molding condition comprises that injection molding temperature is 180 ℃, injection molding pressure is 14MPa, and the injection molding time is 3s, obtains the blank that wall thickness is 5mm.
(3) blank that obtains is put into carried out solvent degreasing in the normal hexane, the condition of described solvent degreasing comprises that skimming temp is 50 ℃, degreasing time is 10h, afterwards the blank after the solvent degreasing is put in the debinding furnace, in 125kPa purity is to carry out hot degreasing under 99.9% the nitrogen atmosphere.
Described hot degreasing comprises three phases, and hot degreasing of fs is meant and is warming up to 300 ℃ in 20min, and keeps this temperature 4h; The hot degreasing of subordinate phase is meant and is warming up to 450 ℃ in 150min, and keeps this temperature 5h; Hot degreasing of phase III is meant and is warming up to 850 ℃ in 40min, and keeps this temperature 2h.
(4) blank after the degreasing is put into sintering in the sintering oven, the atmosphere in the stove is the high pure nitrogen of purity 99.99%, and pressure remains 100kPa, is warming up to 1750 ℃ in 800min, and sintering 3h obtains silicon nitride ceramic material goods A3.
Embodiment 4
Present embodiment is used to illustrate the preparation method of silicon nitride ceramic material provided by the invention.
(1) 100 weight parts are contained 93wt% silicon nitride particle (silicon nitride particle that the novel material Science and Technology Ltd. of section that rubs produces, particle aspect ratio index is 1, median size is 0.8 μ m, α-Si
3N
4Content is 95wt%), the sinter additives of 7wt% puts into high-speed mixer with 28 parts by weight of adhesive and mixes, described blended temperature is 180 ℃, the blended time is 2h, the mixture that will obtain after will mixing subsequently changes in the twin screw extruder and mixes, the blended temperature is 180 ℃, and the blended time is 2h.
Described sinter additives is magnesium oxide and yttrium oxide, is benchmark with described sinter additives total amount, and content of magnesia is 40wt%;
With described binding agent total amount is benchmark, described binding agent contains the high density polyethylene(HDPE) of the paraffin of 42wt%, the ethylene-vinyl acetate copolymer of 22wt% (weight-average molecular weight is 18000, and vinyl acetate between to for plastic accounts for the 22wt% of ethylene-vinyl acetate copolymer), 26wt%, and (density is 0.97g/cm
3) and the oleic acid of 10wt%.
(2) will be in twin screw extruder mixed product broken in pulverizer, the particulate average particle diameter after the fragmentation is 2mm.Particle after the fragmentation is packed in the injection moulding machine, be expelled in the mould with blank structure injection molding afterwards, described injection molding condition comprises that injection molding temperature is 165 ℃, injection molding pressure is 10MPa, and the injection molding time is 3s, obtains the blank that wall thickness is 5mm.
(3) blank that obtains is put into carried out solvent degreasing in the normal hexane, the condition of described solvent degreasing comprises that skimming temp is 50 ℃, degreasing time is 8h, afterwards the blank after the solvent degreasing is put in the debinding furnace, in 125kPa purity is to carry out hot degreasing under 99.9% the nitrogen atmosphere.
Described hot degreasing comprises three phases, and hot degreasing of fs is meant and is warming up to 300 ℃ in 20min, and keeps this temperature 4h; The hot degreasing of subordinate phase is meant and is warming up to 450 ℃ in 150min, and keeps this temperature 5h; Hot degreasing of phase III is meant and is warming up to 850 ℃ in 40min, and keeps this temperature 1h.
(4) blank after the degreasing is put into sintering in the sintering oven, the atmosphere in the stove is the high pure nitrogen of purity 99.99%, and pressure remains 100kPa, is warming up to 1700 ℃ in 1000min, and sintering 4h obtains silicon nitride ceramic material goods A4.
Embodiment 5
Present embodiment is used to illustrate the preparation method of silicon nitride ceramic material provided by the invention.
The preparation method of silicon nitride ceramic material is with embodiment 3, and different is that the silicon nitride particle aspect ratio index that adopts is 1, and median size is 1 μ m.
Make silicon nitride ceramic material goods A5.
Comparative Examples 1
This Comparative Examples is used for illustrating the preparation method of prior art silicon nitride ceramic material
With 100 weight parts contain 90wt% silicon nitride particle (silicon nitride particle that the novel material Science and Technology Ltd. of section that rubs produces, particle aspect ratio index is 1.5, median size is 1 μ m, α-Si
3N
4Content is 85wt%), after the sinter additives of 10wt% mixes by ball milling, add a small amount of concentration and be 5% polyvinyl alcohol water solution as binder, carry out dry-pressing formedly, forming pressure 100MPa obtains idiosome.
Described sinter additives is aluminum oxide and yttrium oxide, is benchmark with described sinter additives total amount, and alumina content is 50wt%.
Idiosome is placed graphite carbon pipe furnace (the graphite carbon pipe furnace that the new big power metallurgy equipment Manufacturing Co., Ltd in Xiangtan City produces), feed purity and be 99.9% nitrogen and carry out hot degreasing, 750 ℃ of skimming temps, degreasing time 24h, gas flow are 25l/min.Base substrate with degreasing after intact is put into sintering in the sintering oven, and the atmosphere in the stove is the high pure nitrogen of purity 99.99%, and pressure remains 100kPa, and at 1600 ℃, sintering 5h obtains silicon nitride ceramic material goods CA1.
Comparative Examples 2
This Comparative Examples is used for illustrating the preparation method of prior art silicon nitride ceramic material
Method is with Comparative Examples 1, and difference is: adopt the method for isostatic cool pressing when making idiosome, forming pressure is 180MPa.
Make silicon nitride ceramic material goods CA2.
Performance test
With the silicon nitride-based material goods A1-A5 that embodiment 1-5 obtains, silicon nitride-based material goods CA1, CA2 that Comparative Examples 1-2 obtains carry out density, room temperature flexural strength, high temperature bend strength and surfaceness test according to following condition.
1, density
Test according to GB/T 2413-1981.
2, room temperature flexural strength
Test according to GB/T 6569-2006.
3, high temperature bend strength
Test according to GB/T 14390-1993.
4, surfaceness
Test according to GB/T 13841-1992.
The results are shown in Table 1 according to above-mentioned test:
Table 1
| The embodiment numbering | The goods numbering | Density (g/cm 3) | Room temperature flexural strength (MPa) | High temperature bend strength (MPa) | Surface roughness Ra (μ m) |
| Embodiment 1 | A1 | 3.12 | 550 | 481 | 1.0 |
| Embodiment 2 | A2 | 3.15 | 620 | 594 | 0.9 |
| Embodiment 3 | A3 | 3.27 | 960 | 730 | 1.0 |
| Embodiment 4 | A4 | 3.31 | 1100 | 863 | 0.8 |
| Embodiment 5 | A5 | 3.30 | 1055 | 810 | 0.9 |
| Comparative Examples 1 | CA1 | 2.65 | 353 | 212 | 11.2 |
| Comparative Examples 2 | CA2 | 3.08 | 212 | 190 | 10.1 |
By the test result of table 1 as can be seen: adopt the surfaceness of silicon nitride ceramics A1-A5 of method preparation disclosed by the invention more much lower than the silicon nitride ceramics CA1-CA2 of traditional method preparation.And the density that adopts the goods A3-A5 that binding agent sintering disclosed by the invention obtains compares CA1 and CA2 also has raising, and the flexural strength under A3-A5 room temperature and the high temperature all significantly promotes.
Contrast A1 and A2, the test result of A3 and A4, A5, as can be seen, the aspect ratio index of silicon nitride particle more near 1, median size is more little, the density of the material that sintering obtains is big more, the flexural strength under room temperature and the high temperature is big more.
The The above results explanation, adopt the surfaceness of the silicon nitride ceramic material of method preparation disclosed by the invention significantly to reduce, its density also has raising, when especially in process of injection molding, adopting binding agent disclosed by the invention, the density of the material that makes is significantly increased, and the flexural strength of the ceramic that obtains at last is largely increased.Simultaneously, the aspect ratio index of silicon nitride particle is more near 1, and promptly silicon nitride particle is got over subglobular, and the density of the silicon nitride ceramic material of preparation is big more, and surfaceness is low more; The silicon nitride particle median size is more little, and the density of the silicon nitride ceramic material of preparation is big more, and surfaceness is low more.Method disclosed by the invention is very suitable for preparation to the demanding silicon nitride ceramic material of surfaceness.
Claims (11)
1, a kind of preparation method of silicon nitride ceramics, this method comprises: silicon nitride particle, sinter additives, caking agent are mixed obtaining mixture, described mixture injection molding is formed blank, to described blank carry out degreasing, sintering makes described silicon nitride ceramics.
2, method according to claim 1 wherein, is a benchmark with described silicon nitride particle and sinter additives gross weight, and described silicon nitride particle content is 80-95wt%.
3, method according to claim 1 wherein, is a benchmark with the gross weight of described silicon nitride particle and sinter additives, and the content of described binding agent is 15-75wt%.
4, method according to claim 1, wherein, described silicon nitride particle aspect ratio index is 1-2.5, the silicon nitride particle median size is not more than 1 μ m.
5, method according to claim 1, wherein said binding agent contains paraffin, ethylene-vinyl acetate copolymer, high density polyethylene(HDPE) and organic acid.
6, method according to claim 5 wherein, is a benchmark with the gross weight of described binding agent, the content of paraffin is 40-60wt%, the content of ethylene-vinyl acetate copolymer is 10-30wt%, and the content of high density polyethylene(HDPE) is 10-30wt%, and organic acid content is 8-12wt%.
7, according to claim 5 or 6 described methods, wherein, described organic acid is oleic acid and/or stearic acid, and the weight-average molecular weight of described ethylene-vinyl acetate copolymer is 2000-20000, and vinyl acetate between to for plastic accounts for the 10-25wt% of ethylene-vinyl acetate copolymer.
8, method according to claim 1, the mixing condition of wherein said mixture are 130-180 ℃, mixing 1-5h; Described injection molding condition is that 140-180 ℃, pressure are that 5-25MPa, time are 2-10s.
9, method according to claim 1, wherein said degreasing comprise solvent degreasing and/or hot degreasing.
10, method according to claim 9, wherein said solvent degreasing is heated to 40-65 ℃ of insulation 5-20h for described blank being put into organic solvent; Described hot degreasing is under the neutral gas atmosphere or vacuum environment of 50kPa-150kPa, at 200-900 ℃ of insulation 3-20h.
11, a kind of silicon nitride ceramics, wherein, this silicon nitride ceramics is to make by any described method among the claim 1-10.
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| CN (1) | CN101591174A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102172960A (en) * | 2010-12-28 | 2011-09-07 | 哈尔滨工业大学 | Powder injection molding method for silicon carbide ceramic sand-blasting nozzle |
| CN104355627A (en) * | 2014-10-29 | 2015-02-18 | 安徽省皖捷液压科技有限公司 | Nanometer silicon nitride wear-resisting ceramic nozzle and preparation method thereof |
| CN105622109A (en) * | 2016-03-17 | 2016-06-01 | 长沙理工大学 | Preparation method of silicon nitride ceramic ball and silicon nitride ceramic ball |
| CN114988882A (en) * | 2022-07-11 | 2022-09-02 | 中材高新氮化物陶瓷有限公司 | Silicon nitride high-temperature ceramic part with complex shape and preparation method thereof |
| CN116535220A (en) * | 2023-05-29 | 2023-08-04 | 共享智能装备有限公司 | Degreasing sintering method of silicon nitride ceramic powder product |
-
2008
- 2008-05-30 CN CNA2008100675482A patent/CN101591174A/en active Pending
Non-Patent Citations (2)
| Title |
|---|
| 徐友仁 等: "氮化硅的α→β相变的影响因素", 《无机材料学报》 * |
| 谢志鹏 等: "陶瓷注射成型的研究", 《硅酸盐学报》 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102172960A (en) * | 2010-12-28 | 2011-09-07 | 哈尔滨工业大学 | Powder injection molding method for silicon carbide ceramic sand-blasting nozzle |
| CN104355627A (en) * | 2014-10-29 | 2015-02-18 | 安徽省皖捷液压科技有限公司 | Nanometer silicon nitride wear-resisting ceramic nozzle and preparation method thereof |
| CN104355627B (en) * | 2014-10-29 | 2016-05-18 | 安徽省皖捷液压科技有限公司 | A kind of nano-silicon nitride wear-resistant ceramic nozzle and preparation method thereof |
| CN105622109A (en) * | 2016-03-17 | 2016-06-01 | 长沙理工大学 | Preparation method of silicon nitride ceramic ball and silicon nitride ceramic ball |
| CN114988882A (en) * | 2022-07-11 | 2022-09-02 | 中材高新氮化物陶瓷有限公司 | Silicon nitride high-temperature ceramic part with complex shape and preparation method thereof |
| CN116535220A (en) * | 2023-05-29 | 2023-08-04 | 共享智能装备有限公司 | Degreasing sintering method of silicon nitride ceramic powder product |
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