CN102221293A - Preparation method of coating for melting crucible - Google Patents
Preparation method of coating for melting crucible Download PDFInfo
- Publication number
- CN102221293A CN102221293A CN2011101521337A CN201110152133A CN102221293A CN 102221293 A CN102221293 A CN 102221293A CN 2011101521337 A CN2011101521337 A CN 2011101521337A CN 201110152133 A CN201110152133 A CN 201110152133A CN 102221293 A CN102221293 A CN 102221293A
- Authority
- CN
- China
- Prior art keywords
- coating
- melting kettle
- crucible
- preparation
- suspension
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Abstract
The invention belongs to the technical field of coating preparation. A preparation method of a coating for a melting crucible comprises the following steps of: pre-drying the melting crucible; preparing a suspension by adopting a PVP (Polyvinyl Pyrrolidone) absolute ethanol solution and silicon nitride; uniformly spraying the suspension on the inner wall of the melting crucible; and pre-burning the melting crucible with sprayed coating to form a silicon nitride coating with uniform thickness and compact structure on the inner wall of the melting crucible. The method has the advantages that: the melting crucible is pre-dried and cleaned before being sprayed to contribute to adhesion of the coating; the PVP absolute ethanol solution is added to the suspension of the coating, the absolute ethanol is evaporated after the crucible is dried, the adhesive PVP leads the coating to be adhered on the inner wall of the crucible, and the coating has higher adhesive force, so that the crucible is prevented from reacting with and adhering melt, smooth demolding of ingots is realized, impurities are prevented from entering melt, the purification effect of the melt is realized, and the using requirement for the coating in a casting process is fulfilled.
Description
Technical field
The invention belongs to the technical field of preparation coating, particularly a kind of on the melting kettle inwall method of spraying silicon nitride coating.
Background technology
Prepare in the ingot casting process in metallurgical melting removal of impurities, all need to use melting kettle, normally used melting kettle is quartz or graphite crucible in the industry, inevitably produces the reaction adhesion when molten metal bath contacts with crucible, and the impurity in the crucible also can enter into silicon melt simultaneously.Reaction adhesion between crucible and the metal, infiltration and diffusion meeting cause problem in the ingot casting knockout course, make polycrystalline silicon ingot casting that the danger of rupturing or breaking be arranged.The impurity of high concentration will produce adverse influence to the various performances of ingot casting as C, O etc.Usually on crucible, be coated with application layer melt and melting kettle wall are isolated, reduce the reaction adhesion and make the smooth demoulding of ingot casting, and stop the impurity in the crucible in casting process, to enter in the metal.
Si
3N
4Because its self-diffusion coefficient is low, high temperature resistant, chemical stability is good, is used as the coating material in the polysilicon casting process usually.The preparation method of silicon nitride coating is a lot, but common complex process, the cost height.Application number is 200810243655.6 patent of invention employing silicon nitride particle and deionized water formation Mag liquation, under low pressure spraying back sintering forms silicon nitride coating, but what use in the method is that deionized water forms the emulsion state liquation, behind the sintering, the adhesive of coating and melting kettle is less, in casting process, very easily come off, thereby can't reach the effect of coating.
Summary of the invention
The objective of the invention is to overcome above-mentioned not enough problem, the preparation method of a kind of melting kettle with coating is provided, utilize PVP ethanol solution and silicon nitride to form suspension, the silicon nitride coating adhesive of spraying back preparation is bigger, thickness is even, compact structure, has satisfied the requirement of isolating crucible and melt in the ingot casting process.
The technical scheme that the present invention is adopted for achieving the above object is: a kind of melting kettle preparation method of coating, at first melting kettle is smoked preliminary treatment, adopt PVP ethanol solution and silicon nitride configuration suspension then, suspension evenly is sprayed at the melting kettle inwall, the melting kettle that will spray coating at last carries out pre-burning to be handled, can the melting kettle inwall obtain a layer thickness evenly, the silicon nitride coating of compact structure.
Described melting kettle is as follows with preparation method's concrete steps of coating:
First step melting kettle is smoked preliminary treatment: melting kettle is put in the directional solidification furnace, is that 3-10Pa, temperature are 600-1000 ℃ of insulation 1-2h down in vacuum, and crucible is taken out in the cold back of stove, cleans the organic solvent of removing on the inwall with acetone;
The second step configuration coating: in the PVP mass percent is the ethanol solution of 6%-15%, add Si
3N
4Powder, stir about 1-2h is uniformly dispersed powder as far as possible, obtains the suspension of silicon nitride coating, set aside for use;
The 3rd step spray coating: the spray gun that cleans up is linked to each other with the air compressor machine gas outlet, sprays with the absolute ethyl alcohol examination earlier, treat that whole passage is smooth and easy after, with the Si that leaves standstill
3N
4The supernatant liquor of suspension is poured in the spray gun, and vaporific powder to be sprayed evenly back sprays to the melting kettle inwall, continuous rotation melting kettle angle in the spraying process, until do not have in appearance obvious dew point and thickness evenly till;
The 4th step pre-burning is handled: the melting kettle that will spray coating places directional solidification furnace, is evacuated down to 3-10Pa, and the 1-2h heat temperature raising is to 800-1000 ℃, and stove is chilled to room temperature behind insulation 1-2h under this temperature, forms the silicon nitride coating of compact structure.
Described melting kettle can be silica crucible, graphite crucible, Al
2O
3Crucible, SiC crucible or MgO crucible when wherein melting kettle is silica crucible, can saves first step melting kettle and smoke pretreated operation.
The PVP mass percent is ethanol solution and the Si of 6%-10% in the described suspension
3N
4The powder mass ratio is 0.3-1.0.
Described Si
3N
4The granularity of powder is the 10-300 micron.
The pressure of described air compressor gas outlet is 100-5000Pa.
The thickness of described silicon nitride coating is 0.5-2mm.
Remarkable result of the present invention is before spraying melting kettle to be smoked preliminary treatment and cleaning treatment, make crucible fine and close clean, help the adhesion of coating, when configuration coating suspension, add the PVP ethanol solution, smoke back absolute ethyl alcohol evaporation, binding agent PVP adheres to coating on the crucible inwall, the adhesive of coating is bigger, in the metal bath casting process, be unlikely to come off, thereby melt and crucible inwall are isolated, prevent the reaction adhesion of crucible and melt, realize the smooth demoulding of ingot casting, prevent that simultaneously impurity from entering liquation, realize the refining effect of melt, satisfied the instructions for use of casting process floating coat.
To sum up, this process is simple, can prepare that a kind of thickness densification, adhesive are big, the silicon nitride coating of compact structure, has realized not coming off of coating, thereby with the effective purpose of isolation of melt and melting kettle.
Description of drawings
Accompanying drawing 1 is the flow chart of melting kettle of the present invention with the preparation method of coating.
The specific embodiment
Describe the present invention in detail below in conjunction with specific embodiments and the drawings, but the present invention is not limited to specific embodiment.
Embodiment 1
The first step is smoked preliminary treatment: select for use " three height " graphite crucible as the melt carrier, because the influence in long-time placement and the process, need smoke processing to crucible, smoking processing procedure carries out in directional solidification furnace, be 5Pa, be incubated 1h down in vacuum at 800 ℃, crucible is taken out in the cold back of stove, cleans the organic solvent of removing on the inwall with acetone;
The suspension of second step configuration silicon nitride coating: adding 30g granularity is 100 microns Si in the ethanol solution of 20g 8wt% PVP
3N
4Powder, stir about 2h is uniformly dispersed powder as far as possible, set aside for use;
The 3rd step spray coating: the spray gun that cleans up is linked to each other with the air compressor machine gas outlet, is 500Pa with air pressure adjustment, sprays with the absolute ethyl alcohol examination earlier, treat that whole passage is smooth and easy after, with the Si that leaves standstill
3N
4The supernatant liquor of suspension is poured in the spray gun, for preventing that excessive powder from entering spray gun and blocking passage, can inject a little suspensions less at every turn.Vaporific powder to be sprayed evenly back sprays to the crucible inwall, to evenly carry out in the spraying process, constantly rotate the crucible angle, until not having obvious dew point and thickness in appearance than till even, coating layer thickness was difficult for thin also being difficult for blocked uply, crossed the thin isolation effect that then can't fully play coating, blocked uply then came off in the preliminary treatment in later stage and fusion process easily, the effect of coating be can weaken equally, and the silicon ingot and the difficulty more that becomes separating of crucible after the melting made;
The 4th step pre-burning is handled: the crucible that will spray coating carries out pre-burning to be handled, remove wherein residual liquid phase and organic principle, prevent after these compositions of fusion process enter into melt, the pre-burning processing procedure is carried out in directional solidification furnace, the graphite crucible that has sprayed coating is placed directional solidification furnace, be evacuated down to 4Pa, 1h heat temperature raising to 800 ℃, stove is chilled to room temperature behind insulation 1h under this temperature, forms the silicon nitride coating that a layer thickness is the compact structure of 0.8mm.Crucible after pre-burning handled is placed in the clean environment, avoids polluting and the entering of impurity.
Embodiment 2
The first step is smoked preliminary treatment: select Al for use
2O
3Crucible is as the melt carrier, because the influence in long-time placement and the process, need smoke processing to crucible, smoking processing procedure carries out in directional solidification furnace, be 8Pa, be incubated 1h down in vacuum at 600 ℃, crucible is taken out in the cold back of stove, cleans the organic solvent of removing on the inwall with acetone;
The suspension of second step configuration silicon nitride coating: adding 20g granularity is 130 microns Si in the ethanol solution of 10g 6wt% PVP
3N
4Powder, stir about 2h is uniformly dispersed powder as far as possible, set aside for use;
The 3rd step spray coating: the spray gun that cleans up is linked to each other with the air compressor machine gas outlet, is 300Pa with air pressure adjustment, sprays with the absolute ethyl alcohol examination earlier, treat that whole passage is smooth and easy after, with the Si that leaves standstill
3N
4The supernatant liquor of suspension is poured in the spray gun, for preventing that excessive powder from entering spray gun and blocking passage, can inject a little suspensions less at every turn.Vaporific powder to be sprayed evenly back sprays to the crucible inwall, to evenly carry out in the spraying process, constantly rotate the crucible angle, until not having obvious dew point and thickness in appearance than till even, coating layer thickness was difficult for thin also being difficult for blocked uply, crossed the thin isolation effect that then can't fully play coating, blocked uply then came off in the preliminary treatment in later stage and fusion process easily, the effect of coating be can weaken equally, and the silicon ingot and the difficulty more that becomes separating of crucible after the melting made;
The 4th step pre-burning is handled: the crucible that will spray coating carries out pre-burning to be handled, remove wherein residual liquid phase and organic principle, prevent after these compositions of fusion process enter into melt, the pre-burning processing procedure is carried out in directional solidification furnace, the graphite crucible that has sprayed coating is placed directional solidification furnace, be evacuated down to 6Pa, 2h heat temperature raising to 900 ℃, stove is chilled to room temperature behind insulation 3h under this temperature, forms the silicon nitride coating that a layer thickness is the compact structure of 0.6mm.Crucible after pre-burning handled is placed in the clean environment, avoids polluting and the entering of impurity.
It is consistent through case test that the present invention prepares silicon nitride coating, and technology is simple, and coating performance is good, and energy consumption is little, and cost is low, and the cycle is short, and production efficiency is higher.
Claims (7)
1. a melting kettle is with the preparation method of coating, it is characterized in that, at first melting kettle is smoked preliminary treatment, adopt PVP ethanol solution and silicon nitride configuration suspension then, suspension evenly is sprayed at the melting kettle inwall, the melting kettle that will spray coating at last carries out pre-burning to be handled, can the melting kettle inwall obtain a layer thickness evenly, the silicon nitride coating of compact structure.
2. a kind of melting kettle according to claim 1 preparation method of coating is characterized in that concrete steps are as follows:
First step melting kettle is smoked preliminary treatment: melting kettle is put in the directional solidification furnace, is that 3-10Pa, temperature are 600-1000 ℃ of insulation 1-2h down in vacuum, and crucible is taken out in the cold back of stove, cleans the organic solvent of removing on the inwall with acetone;
The second step configuration coating: in the PVP mass percent is the ethanol solution of 6%-15%, add Si
3N
4Powder, stir about 1-2h is uniformly dispersed powder as far as possible, obtains the suspension of silicon nitride coating, set aside for use;
The 3rd step spray coating: the spray gun that cleans up is linked to each other with the air compressor machine gas outlet, sprays with the absolute ethyl alcohol examination earlier, treat that whole passage is smooth and easy after, with the Si that leaves standstill
3N
4The supernatant liquor of suspension is poured in the spray gun, and vaporific powder to be sprayed evenly back sprays to the melting kettle inwall, continuous rotation melting kettle angle in the spraying process, until do not have in appearance obvious dew point and thickness evenly till;
The 4th step pre-burning is handled: the melting kettle that will spray coating places directional solidification furnace, is evacuated down to 3-10Pa, and the 1-2h heat temperature raising is to 800-1000 ℃, and stove is chilled to room temperature behind insulation 1-2h under this temperature, forms the silicon nitride coating of compact structure.
3. a kind of melting kettle according to claim 1 and 2 is characterized in that with the preparation method of coating described melting kettle can be silica crucible, graphite crucible, Al
2O
3Crucible, SiC crucible or MgO crucible when wherein melting kettle is silica crucible, can saves first step melting kettle and smoke pretreated operation.
4. a kind of melting kettle according to claim 1 and 2 is characterized in that with the preparation method of coating the PVP mass percent is ethanol solution and the Si of 6%-10% in the described suspension
3N
4The powder mass ratio is 0.3-1.0.
5. a kind of melting kettle according to claim 1 and 2 is characterized in that described Si with the preparation method of coating
3N
4The granularity of powder is the 10-300 micron.
6. a kind of melting kettle according to claim 1 and 2 is characterized in that with the preparation method of coating the pressure of described air compressor gas outlet is 100-5000Pa.
7. a kind of melting kettle according to claim 1 and 2 is characterized in that with the preparation method of coating the thickness of described silicon nitride coating is 0.5-2mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201110152133 CN102221293B (en) | 2011-06-08 | 2011-06-08 | Preparation method of coating for melting crucible |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201110152133 CN102221293B (en) | 2011-06-08 | 2011-06-08 | Preparation method of coating for melting crucible |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102221293A true CN102221293A (en) | 2011-10-19 |
| CN102221293B CN102221293B (en) | 2013-05-08 |
Family
ID=44777918
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201110152133 Expired - Fee Related CN102221293B (en) | 2011-06-08 | 2011-06-08 | Preparation method of coating for melting crucible |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102221293B (en) |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102850086A (en) * | 2012-09-20 | 2013-01-02 | 光为绿色新能源股份有限公司 | Preparation method for ceramic crucible sintering-free coating for polysilicon ingot |
| CN103130528A (en) * | 2011-12-05 | 2013-06-05 | 江苏协鑫硅材料科技发展有限公司 | Sintering-free crucible coating structure for ingot casting of polycrystalline silicon and manufacture method thereof |
| CN103132141A (en) * | 2011-12-05 | 2013-06-05 | 江苏协鑫硅材料科技发展有限公司 | Coating composition of graphite equipment used for polycrystalline silicon ingot furnace |
| CN103288357A (en) * | 2013-06-20 | 2013-09-11 | 天津英利新能源有限公司 | Silicon nitride solution and preparation method, and polysilicon ingot casting crucible and making method thereof |
| CN104668503A (en) * | 2013-11-30 | 2015-06-03 | 中国科学院金属研究所 | Amorphous alloy member cast forming device and process |
| CN104668504A (en) * | 2013-11-30 | 2015-06-03 | 中国科学院金属研究所 | Casting forming equipment and process for amorphous alloy component |
| CN104962991A (en) * | 2015-05-26 | 2015-10-07 | 江苏润弛太阳能材料科技有限公司 | Quartz crucible and production method thereof |
| CN105063757A (en) * | 2015-09-17 | 2015-11-18 | 晶科能源有限公司 | Low-oxygen spraying method |
| CN105779912A (en) * | 2014-12-26 | 2016-07-20 | 比亚迪股份有限公司 | Method for prolonging service life of amorphous alloy smelting crucible and smelting method for amorphous alloy |
| CN107602139A (en) * | 2017-10-24 | 2018-01-19 | 陕西海恩得工贸有限公司 | A kind of material of melting titanium or titanium alloy crucible and the preparation method of crucible |
| CN110418858A (en) * | 2017-03-14 | 2019-11-05 | 申克碳化技术股份有限公司 | Coated product and production method |
| US11534794B2 (en) | 2019-06-24 | 2022-12-27 | Sino-American Silicon Products Inc. | Crucible structure and method for forming isolating layer of crucible |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040198676A1 (en) * | 2003-04-04 | 2004-10-07 | Soll Mark D. | Topical anthelmintic veterinary formulations |
| WO2007076852A1 (en) * | 2006-01-06 | 2007-07-12 | LABTEC Gesellschaft für technologische Forschung und Entwicklung mbH | Self-adhesive semi-occlusive plaster dressing for atopical dermatitis |
| CN101428273A (en) * | 2008-12-05 | 2009-05-13 | 江阴海润太阳能电力有限公司 | Silicon nitride spray finishing method for quartz crucible for polysilicon solar battery casting ingot |
| CN101433890A (en) * | 2008-12-05 | 2009-05-20 | 江阴海润太阳能电力有限公司 | Method and device for spraying silicon nitride coating on inner wall of quartz crucible under low pressure |
-
2011
- 2011-06-08 CN CN 201110152133 patent/CN102221293B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040198676A1 (en) * | 2003-04-04 | 2004-10-07 | Soll Mark D. | Topical anthelmintic veterinary formulations |
| WO2007076852A1 (en) * | 2006-01-06 | 2007-07-12 | LABTEC Gesellschaft für technologische Forschung und Entwicklung mbH | Self-adhesive semi-occlusive plaster dressing for atopical dermatitis |
| CN101428273A (en) * | 2008-12-05 | 2009-05-13 | 江阴海润太阳能电力有限公司 | Silicon nitride spray finishing method for quartz crucible for polysilicon solar battery casting ingot |
| CN101433890A (en) * | 2008-12-05 | 2009-05-20 | 江阴海润太阳能电力有限公司 | Method and device for spraying silicon nitride coating on inner wall of quartz crucible under low pressure |
Non-Patent Citations (1)
| Title |
|---|
| 刘美: "冶金法提纯多晶硅过程中氮化硅涂层的研究", 《工程科技Ⅰ辑》 * |
Cited By (19)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103130528A (en) * | 2011-12-05 | 2013-06-05 | 江苏协鑫硅材料科技发展有限公司 | Sintering-free crucible coating structure for ingot casting of polycrystalline silicon and manufacture method thereof |
| CN103132141A (en) * | 2011-12-05 | 2013-06-05 | 江苏协鑫硅材料科技发展有限公司 | Coating composition of graphite equipment used for polycrystalline silicon ingot furnace |
| CN103130528B (en) * | 2011-12-05 | 2014-06-11 | 江苏协鑫硅材料科技发展有限公司 | Sintering-free crucible coating structure for ingot casting of polycrystalline silicon and manufacture method thereof |
| CN102850086A (en) * | 2012-09-20 | 2013-01-02 | 光为绿色新能源股份有限公司 | Preparation method for ceramic crucible sintering-free coating for polysilicon ingot |
| CN103288357B (en) * | 2013-06-20 | 2016-03-30 | 天津英利新能源有限公司 | Silicon nitride solution and preparation method thereof, crucible used for polycrystalline silicon ingot casting and preparation method thereof |
| CN103288357A (en) * | 2013-06-20 | 2013-09-11 | 天津英利新能源有限公司 | Silicon nitride solution and preparation method, and polysilicon ingot casting crucible and making method thereof |
| CN104668504B (en) * | 2013-11-30 | 2017-06-16 | 中国科学院金属研究所 | Non-crystaline amorphous metal component casting equipment and technique |
| CN104668504A (en) * | 2013-11-30 | 2015-06-03 | 中国科学院金属研究所 | Casting forming equipment and process for amorphous alloy component |
| CN104668503B (en) * | 2013-11-30 | 2017-05-31 | 中国科学院金属研究所 | A kind of non-crystaline amorphous metal component casting equipment and technique |
| CN104668503A (en) * | 2013-11-30 | 2015-06-03 | 中国科学院金属研究所 | Amorphous alloy member cast forming device and process |
| CN105779912A (en) * | 2014-12-26 | 2016-07-20 | 比亚迪股份有限公司 | Method for prolonging service life of amorphous alloy smelting crucible and smelting method for amorphous alloy |
| CN104962991A (en) * | 2015-05-26 | 2015-10-07 | 江苏润弛太阳能材料科技有限公司 | Quartz crucible and production method thereof |
| CN104962991B (en) * | 2015-05-26 | 2018-04-17 | 江苏润弛太阳能材料科技有限公司 | A kind of silica crucible and preparation method thereof |
| CN105063757A (en) * | 2015-09-17 | 2015-11-18 | 晶科能源有限公司 | Low-oxygen spraying method |
| CN105063757B (en) * | 2015-09-17 | 2017-12-29 | 晶科能源有限公司 | A kind of hypoxemia spraying method |
| CN110418858A (en) * | 2017-03-14 | 2019-11-05 | 申克碳化技术股份有限公司 | Coated product and production method |
| US11932937B2 (en) | 2017-03-14 | 2024-03-19 | Schunk Kohlenstofftechnik Gmbh | Coated product and production method |
| CN107602139A (en) * | 2017-10-24 | 2018-01-19 | 陕西海恩得工贸有限公司 | A kind of material of melting titanium or titanium alloy crucible and the preparation method of crucible |
| US11534794B2 (en) | 2019-06-24 | 2022-12-27 | Sino-American Silicon Products Inc. | Crucible structure and method for forming isolating layer of crucible |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102221293B (en) | 2013-05-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102221293B (en) | Preparation method of coating for melting crucible | |
| CN103521715B (en) | A kind of preparation method of the titanium or titanium alloy precision casting containing elongated lumens | |
| CN112144115B (en) | Quartz crucible with long service life and low deformation rate and preparation method thereof | |
| CN106927802A (en) | A kind of manufacture method for noting solidification forming fused silica crucible | |
| CN106498350A (en) | The preparation method of sial sputtering target material | |
| CN107056255A (en) | A kind of calcium oxide filter and preparation method thereof | |
| CN104439049B (en) | Alcohol radical ceramic casting coating | |
| CN110560629B (en) | Coating for smelting and casting high-purity aluminum and preparation method and application thereof | |
| CN105779912A (en) | Method for prolonging service life of amorphous alloy smelting crucible and smelting method for amorphous alloy | |
| CN102181856B (en) | Method for preparing complex gradient material by using cold spraying technology | |
| CN102898034B (en) | Preparation method of crucible silicon nitride coating for crystalline silicon cast ingot | |
| CN202267357U (en) | Water cooling device of graphite and coating substrate for electron beam melting | |
| CN103663985B (en) | A kind of manufacture method of conducting plate glass | |
| CN100415945C (en) | Method of improving life of straight pulling silicon single crystal furnace thermal field component and single crystal furnace | |
| CN103240403A (en) | Surface casting infiltration process suitable for pure copper blast-furnace tuyere sleeve | |
| CN105603374B (en) | One kind prepares Si on polysilicon ingot crucible3N4The method of film | |
| CN112662983A (en) | Preparation method of porous layer on surface of titanium and titanium alloy | |
| JP2013095652A (en) | Silica sintered body crucible | |
| CN108330307A (en) | A kind of electric arc spraying zinc-copper-titanium alloy silk material and its preparation process | |
| CN102978551A (en) | Heat treatment method for preventing Li removal and oxidization of Mg-Li based magnesium alloy surface | |
| CN103060576A (en) | Composite centrifugal purification method of zinc and zinc alloy melt | |
| CN104528733A (en) | Device and method for separating high-metal-impurity region from cast ingot | |
| CN103273054A (en) | Copper powder and heat radiating piece using same | |
| CN100584977C (en) | Zinc pot and its machining process | |
| JP2002307150A (en) | Method for producing cast iron tube |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20130508 Termination date: 20160608 |