JPH0585499B2 - - Google Patents
Info
- Publication number
- JPH0585499B2 JPH0585499B2 JP2418874A JP41887490A JPH0585499B2 JP H0585499 B2 JPH0585499 B2 JP H0585499B2 JP 2418874 A JP2418874 A JP 2418874A JP 41887490 A JP41887490 A JP 41887490A JP H0585499 B2 JPH0585499 B2 JP H0585499B2
- Authority
- JP
- Japan
- Prior art keywords
- weight
- mullite
- sio
- less
- zro
- 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.)
- Expired - Fee Related
Links
- KZHJGOXRZJKJNY-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Si]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O KZHJGOXRZJKJNY-UHFFFAOYSA-N 0.000 claims description 35
- 229910052863 mullite Inorganic materials 0.000 claims description 35
- 229910018072 Al 2 O 3 Inorganic materials 0.000 claims description 31
- 229910004298 SiO 2 Inorganic materials 0.000 claims description 29
- 239000013078 crystal Substances 0.000 claims description 13
- 239000000843 powder Substances 0.000 description 18
- 239000002994 raw material Substances 0.000 description 18
- 238000000034 method Methods 0.000 description 17
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 14
- 239000002245 particle Substances 0.000 description 13
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 12
- 238000010304 firing Methods 0.000 description 12
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 11
- 239000000919 ceramic Substances 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 9
- 230000007423 decrease Effects 0.000 description 9
- 238000000465 moulding Methods 0.000 description 9
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 7
- 238000005260 corrosion Methods 0.000 description 7
- 230000007797 corrosion Effects 0.000 description 7
- 239000000203 mixture Substances 0.000 description 7
- 150000001875 compounds Chemical class 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 238000000227 grinding Methods 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 6
- 238000005245 sintering Methods 0.000 description 6
- 239000000463 material Substances 0.000 description 5
- 238000002156 mixing Methods 0.000 description 5
- 239000000377 silicon dioxide Substances 0.000 description 5
- 229910052573 porcelain Inorganic materials 0.000 description 4
- 230000001737 promoting effect Effects 0.000 description 4
- 235000012239 silicon dioxide Nutrition 0.000 description 4
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 3
- 229910052681 coesite Inorganic materials 0.000 description 3
- 229910052906 cristobalite Inorganic materials 0.000 description 3
- 239000010433 feldspar Substances 0.000 description 3
- 229940088417 precipitated calcium carbonate Drugs 0.000 description 3
- 230000035939 shock Effects 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 229910052682 stishovite Inorganic materials 0.000 description 3
- 229910052905 tridymite Inorganic materials 0.000 description 3
- 241000270666 Testudines Species 0.000 description 2
- 239000004480 active ingredient Substances 0.000 description 2
- 238000011109 contamination Methods 0.000 description 2
- 229910052593 corundum Inorganic materials 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000001125 extrusion Methods 0.000 description 2
- 230000017525 heat dissipation Effects 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 239000011505 plaster Substances 0.000 description 2
- 238000010298 pulverizing process Methods 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- 239000007858 starting material Substances 0.000 description 2
- 238000005979 thermal decomposition reaction Methods 0.000 description 2
- 229910001845 yogo sapphire Inorganic materials 0.000 description 2
- IVORCBKUUYGUOL-UHFFFAOYSA-N 1-ethynyl-2,4-dimethoxybenzene Chemical compound COC1=CC=C(C#C)C(OC)=C1 IVORCBKUUYGUOL-UHFFFAOYSA-N 0.000 description 1
- 239000005995 Aluminium silicate Substances 0.000 description 1
- 238000004438 BET method Methods 0.000 description 1
- 229920001353 Dextrin Polymers 0.000 description 1
- 239000004375 Dextrin Substances 0.000 description 1
- KKCBUQHMOMHUOY-UHFFFAOYSA-N Na2O Inorganic materials [O-2].[Na+].[Na+] KKCBUQHMOMHUOY-UHFFFAOYSA-N 0.000 description 1
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 1
- 239000004372 Polyvinyl alcohol Substances 0.000 description 1
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 1
- 229910010413 TiO 2 Inorganic materials 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 235000012211 aluminium silicate Nutrition 0.000 description 1
- 238000000498 ball milling Methods 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 239000004927 clay Substances 0.000 description 1
- 238000000975 co-precipitation Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 235000019425 dextrin Nutrition 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000002706 hydrostatic effect Effects 0.000 description 1
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 239000003562 lightweight material Substances 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229920000609 methyl cellulose Polymers 0.000 description 1
- 239000001923 methylcellulose Substances 0.000 description 1
- 235000011837 pasties Nutrition 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- NOTVAPJNGZMVSD-UHFFFAOYSA-N potassium monoxide Inorganic materials [K]O[K] NOTVAPJNGZMVSD-UHFFFAOYSA-N 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000001272 pressureless sintering Methods 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 230000003763 resistance to breakage Effects 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 229910052596 spinel Inorganic materials 0.000 description 1
- 239000011029 spinel Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 238000001694 spray drying Methods 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 239000002562 thickening agent Substances 0.000 description 1
Landscapes
- Tunnel Furnaces (AREA)
- Compositions Of Oxide Ceramics (AREA)
Description
ã0001ã[0001]
ãç£æ¥äžã®å©çšåéã æ¬çºæã¯ãé«æž©åºŠã§äœ¿çš
ã§ããèä¹
æ§ã«åªããã ã©ã€ãçŒçµäœã«é¢ãããTECHNICAL FIELD The present invention relates to a mullite sintered body that can be used at high temperatures and has excellent durability.
ã0002ã[0002]
ãåŸæ¥ã®æè¡åã³ãã®åé¡ç¹ã ã ã©ã€ãç£åš
ã¯ãå€ãããçååŠçšé¶ç£åšãç±åŠçãè¡ãããŒ
ã©ãŒããŒã¹ãã«ã³çšã®ããŒã©ãŒãªã©ãšããŠäœ¿çšã
ããŠããã[Prior art and its problems] Mullite porcelain has been used for a long time as ceramics for physics and chemistry, rollers for roller hearth kilns that perform heat treatment, and the like.
ã0003ã äŸãã°ãããŒã©ãŒããŒã¹ãã«ã³ã¯ã被
çŒæäœã移åãããããã«å¿
èŠãªéšæã®ç±å®¹éã
極端ã«å°ãããããç±å¹çã倧巟ã«åäžãããšå
±
ã«ãç±åŠçæéãççž®ããããšããå©ç¹ãããã
è¿å¹Žæ®åãã€ã€ããã[0003] For example, roller hearth kilns have the advantage of greatly improving thermal efficiency and shortening heat treatment time because the heat capacity of the members required to move the object to be fired is extremely small.
It has become popular in recent years.
ã0004ã ããŒã©ãŒããŒã¹ãã«ã³çšã®ããŒã©ãŒãš
ããŠã¯ãçŸåšãã¹ãã³ã¬ã¹ãèç±åéãé¶åšãã
ã©ã€ãç£åšãã¢ã«ããçã®ããŒã©ãŒã䜿çšãããŠ
ãããããããªãããéå±è£œããŒã©ãŒã§ã¯ã1000
â以äžãé¶åšãç£åšè£œã®ããŒã©ãŒã§ã¯1250â以äž
ã®çã«äœ¿çšãéå®ãããã¢ã«ãã補ããŒã©ãŒã¯æ¥µ
å°åã®ãã¹ãçã«çšããããŠããçšåºŠã§ãããç±
åŠç枩床ã«å€§ããªéçããããæŽã«ããããã®ã
ãŒã©ãŒã¯ãäžæ¬åœãã«ãããè·éã«å¶çŽãããã
容ç©åœãã®çŒæééã«éçããããããã¿ã€ã«ã
é£åšãªã©ã®äœæž©çŒæã®è»œéææã®ç±åŠçã«å©çšã
ããŠããã«ãšã©ãŸã€ãŠããã[0004] Currently, rollers made of stainless steel, heat-resistant alloys, ceramics, mullite porcelain, alumina, etc. are used as rollers for roller hearth kilns. However, with metal rollers, 1000
â or less, ceramic or porcelain rollers can only be used in furnaces with temperatures below 1250â, and alumina rollers are only used in extremely small test furnaces, and there is a big limit to the heat treatment temperature. Furthermore, these rollers have restrictions on the load that can be applied to each roller.
Because there is a limit to the firing weight per volume, tiles,
It is currently only used for heat treatment of lightweight materials that are fired at low temperatures, such as tableware.
ã0005ã ãããã«ãä»åŸã®çª¯æ¥è£œåãç¹ã«ãã
ããã¢ããã³ã¹ãã»ã»ã©ããã¯ã¹ã®æ®åã«ã¯ãç±
åŠçå·¥çšã®çãšãã«ã®ãŒåãšé«éåã®éèŠæ§ãå¢
倧ããŠãããšèããããããã®ãããããŒã©ãŒã
ãŒã¹ãã«ã³çšã®ããŒã©ãŒãšããŠã¯ãæ©æ¢°ç匷床ã
é«ãããšãç±æºåã³è¢«ç±åŠçææããã«é£æ£èžçº
ç©ã«å¯ŸããŠèé£æ§ã«åªããŠããããšãé«æž©äžã«ã
ããŠé±æ§ãé«ããã¯ãªãŒãã«ãã€ãŠç Žæãããã«
ããããšãèç±è¡ææµæãé«ããèä¹
æ§ã«ããã
ãŠããããšãç±æŸæ£ãå°ããããšãªã©ã®èŠæ±ãæº
足ãããã®ãæãŸãŠããã[0005] However, with the future spread of ceramic products, especially so-called advanced ceramics, it is thought that the importance of energy saving and speeding up of heat treatment processes will increase. For this reason, rollers for roller hearth kilns must have high mechanical strength, excellent corrosion resistance against evaporated matter from heat sources and heat-treated materials, high toughness at high temperatures, and resistance to creep. What is desired is a material that satisfies the requirements of resistance to breakage, high thermal shock resistance, excellent durability, and low heat dissipation.
ã0006ã ããããªããããã®æ§ãªèŠæ±ã«å¯Ÿã
ãŠãåŸæ¥ã®ã ã©ã€ãç£åšã§ã¯ãååã«å¿ããããš
ãã§ããªãã€ãã[0006] However, conventional mullite porcelain has not been able to fully meet these demands.
ã0007ãã0007ã
ãåé¡ç¹ã解決ããããã®æ段ã æ¬çºæè
ã¯ã
åŸæ¥æè¡ã®æ¬ ç¹ã«éã¿ãŠãéæç 究ãéããçµ
æãæ©æ¢°ç匷床ãé«ããèé£æ§ã«åªããé«æž©åºŠã«
ãããŠææ§é ã§äžã€ã¯ãªãŒãç Žæããã«ãããè
ç±è¡ææµæãé«ããèä¹
æ§ã«åªããç¹å®ã®ã ã©ã€
ãçŒçµäœãããã®èŠæ±ãã¿ããããšãèŠãåºãã
ãã®ç¥èŠã«åºããŠæ¬çºæãå®æããã[Means for solving the problem] The present inventor
In view of the shortcomings of the conventional technology, as a result of extensive research, we have developed a specific technology that has high mechanical strength, excellent corrosion resistance, has a flexible structure and is resistant to creep rupture at high temperatures, has high thermal shock resistance, and has excellent durability. We discovered that sintered mullite satisfies this requirement.
The present invention was completed based on this knowledge.
ã0008ã å³ã¡ãæ¬çºæã¯ãïœïŒAl2O3åã³SiO2
ã®åèšé97.0ééïŒ
以äžãïŒCaO 0.2ééïŒ
以
äžãïŒNa2åã³K2ã®åèšé0.2ééïŒ
以äžã
䞊ã³ã«ïŒZrO2 0.05ã2.8ééïŒ
ã§ãããAl2
O3ïŒSiO2ïŒã¢ã«æ¯ïŒïŒ1.30ã1.85ãããå¯åºŠ2.96
ïœïŒcm3以äžã§ããã ã©ã€ãçµæ¶ãäž»äœãšããã ã©
ã€ãçŒçµäœã«ä¿ããã[0008] That is, the present invention provides i) Al 2 O 3 and SiO 2
Total amount of 97.0% by weight or more,) CaO 0.2% by weight or less,) Total amount of Na 2 O and K 2 O 0.2% by weight or less,
and) ZrO2 0.05-2.8% by weight, Al2
O 3 /SiO 2 (molar ratio) = 1.30 to 1.85, bulk density 2.96
It pertains to a mullite sintered body mainly composed of mullite crystals with a particle size of g/cm 3 or more.
ã0009ã æ¬çºæã§ããã ã©ã€ãçµæ¶ãäž»äœãšã
ãçŒçµäœã¯ãã ã©ã€ãåºæº¶äœã®ã¿ãããªãçŒçµäœ
ã«éå®ããããçµæ¶ç²çã«ååšããéæ¶è³ªãããª
ãã¯ã¹ãå°ãªããäžã€ã¢ã«ããçµæ¶ïŒÎ±âAl2
O3ïŒãã ã©ã€ãçµæ¶ã®10容éïŒ
以äžããå«ãŸã
ãªãçŒçµäœã§ããã°ãããå
·äœçã«ã¯ä»¥äžã®æ¡ä»¶
ãæºè¶³ãããã®ã§ããã[0009] The sintered body mainly composed of mullite crystals in the present invention is not limited to a sintered body consisting only of mullite solid solution, but has a small amount of amorphous matrix present in the grain boundaries and alumina crystals (α- Al 2
It is sufficient that the sintered body contains 10% by volume or less of O 3 ) of the mullite crystals, and specifically satisfies the following conditions.
ã0010ã ïœïŒAl2O3ïŒSiO2ïŒã¢ã«æ¯ïŒã1.30ã
1.85ã®ç¯å²å
ã§ãããAl2O3ïŒSiO2ã1.30ãäžå
ãå Žåã«ã¯ãã ã©ã€ãçµæ¶çžéãæžå°ããSiO2
ãŸãã¯éæ¶è³ªçžãå¢å ãããããé«æž©ã¯ãªãŒãã®
äœäžãèé£æ§ã®äœäžãããããèä¹
æ§ãå£ããã
ã«ãªããäžæ¹ãAl2O3ïŒSiO2ã1.85ãäžåãå Žå
ã«ã¯ãã ã©ã€ãçµæ¶çžã®ä»ã«Al2O3çµæ¶çžéãå¢
å ããé«æž©åŒ·åºŠãé±æ§ã®äœäžåã³èä¹
æ§ã®äœäžã
çããã®ã§äžé©åœã§ããã[0010] a) Al 2 O 3 /SiO 2 (molar ratio) is 1.30 ~
It is within the range of 1.85. When Al 2 O 3 /SiO 2 is less than 1.30, the amount of mullite crystal phase decreases and SiO 2
Or, since the amorphous phase increases, high-temperature creep and corrosion resistance decrease, resulting in poor durability. On the other hand, when Al 2 O 3 /SiO 2 exceeds 1.85, the amount of Al 2 O 3 crystal phase increases in addition to the mullite crystal phase, resulting in a decrease in high-temperature strength, toughness, and durability, making it unsuitable. It is.
ã0011ã ïœïŒAl2O3åã³SiO2ã®åèšéã97.0é
éïŒ
以äžã§ãããAl2O3åã³SiO2ã®åèšéã¯ãå€
ãããšãæãŸãããå¿
ãããçµæžçã§ãªãããŸ
ããTiO2ãCr2O3ãY2O3çã®æåã¯ãçŒçµäœã®
é«æž©ç¹æ§ã«ã€ããŠã¯ãè¥å¹²ã®å質äœäžèŠå ãšãªã
ããçŒçµä¿é²ãé±æ§åäžãªã©ã®å¹æããããåŸã€
ãŠãããã®æåãå«ãAl2O3åã³SiO2以å€ã®æå
ã¯ãïŒïŒ
æªæºã§ããã°èš±å®¹ã§ããããããAl2O3
åã³SiO2ã®åèšéã97ééïŒ
ãäžåããšãç±æº
ã被åŠçç©ããã®é£æ£èžçºç©ã«å¯Ÿããèé£æ§ã®äœ
äžãé«æž©ã¯ãªãŒãã®äœäžãªã©ãçããã®ã§å¥œãŸã
ããªããb) The total amount of Al 2 O 3 and SiO 2 is 97.0% by weight or more. Although it is desirable that the total amount of Al 2 O 3 and SiO 2 be large, it is not necessarily economical. In addition, components such as TiO 2 , Cr 2 O 3 and Y 2 O 3 cause a slight deterioration in the high-temperature properties of the sintered body, but they have effects such as promoting sintering and improving toughness. Therefore, components other than Al 2 O 3 and SiO 2 containing these components are permissible as long as they are less than 3%. But Al 2 O 3
If the total amount of SiO 2 and SiO 2 is less than 97% by weight, it is not preferable because corrosion resistance to flying evaporates from the heat source or the object to be treated decreases, and high-temperature creep decreases.
ã0012ã ïœïŒCaOã®å«æéã¯ã0.2ééïŒ
以äž
ãšããã
CaOã®å«æéãå¢å ãããšCaOâAl2O3âSiO2ç³»
ã®ååç©ã圢æããããšèããããé«æž©ã§ã¯ãªãŒ
ãç Žæãå¢å ããã®ã§å¥œãŸãããªãããã®ãã
CaOã®å«æéã¯0.2ééïŒ
以äžãšããããšãå¿
èŠ
ã§ããã奜ãŸããã¯0.1ééïŒ
以äžãããã«å¥œãŸ
ããã¯0.05ééïŒ
以äžãšããã[0012] c) The content of CaO is 0.2% by weight or less. If the content of CaO increases, it is thought that a CaO- Al2O3 - SiO2 - based compound will be formed, which is not preferable because creep rupture increases at high temperatures. For this reason
The content of CaO needs to be 0.2% by weight or less, preferably 0.1% by weight or less, and more preferably 0.05% by weight or less.
ã0013ã ïœïŒNa2ãšK2ã®åèšå«æéã¯ã
0.2ééïŒ
以äžãšããã
Na2åã³K2ã®å«æéãå¢å ãããšNa2ãŸã
ã¯ïŒããã³K2âAl2O3âSiO2ç³»ååç©ã圢æã
ããå質ã寿åœãªã©ãäœäžããã®ã§ãããã®å«æ
éã¯ã0.2ééïŒ
以äžãšãã奜ãŸããã¯0.1ééïŒ
以äžãšããã[0013] d) The total content of Na 2 O and K 2 O is
The content shall be 0.2% by weight or less. If the content of Na 2 O and K 2 O increases, Na 2 O or/and K 2 O-Al 2 O 3 -SiO 2- based compounds will be formed, resulting in a decrease in quality and life. 0.2% by weight or less, preferably 0.1% by weight
The following shall apply.
ã0014ã ïœ
ïŒZrO2ã®å«æéã¯ã0.05ã2.8éé
ïŒ
ãšããã
ZrO2ã¯ãã ã©ã€ãçŒçµäœã®çŒçµä¿é²ã®å¹æãã
ããã ã©ã€ããæå®éå«æãããããšã«ãã€ãŠã
çŒçµæ§ãåäžããŠãããå¯åºŠãäœãå Žåã«çãã
èé£æ§ãæ©æ¢°ç匷床ã®äœäžãé²æ¢ããããšãã§ã
ãããã®çŒçµä¿é²å¹æã¯ãZrO2ãçŒçµéçšã«ã
ããŠãã ã©ã€ãçµæ¶ã®ç²çã«ååšããããšãšãªã€
ãŠãç²çã«ãããã ã©ã€ãã®çžäºæ¡æ£ãä¿é²ãã
ããšã«ãããã®ãšæšæž¬ãããããŸãåæã«ã
ZrO2ã®ååšããã ã©ã€ãçµæ¶ç²çã«çããéæ¶
質ãããªãã¯ã¹ã®åæãæå¶ããå¹æãšããŠå
ããé«æž©ã«ãããã ã©ã€ãçŒçµäœã®é±æ§åäžãã¯
ãªãŒãç¹æ§ã®æ¹åã«å¯äžãããããããäžæ¹ã
ZrO2ã¯ãç±æºã被ç±åŠçææããã®é«æž©ã«ãã
ãé£æ£èžçºç©ã«ããæ±æã«äŒŽãèä¹
æ§ã®äœäžãã
ãããªã©ã®æ¬ ç¹ããããZrO2ã®å«æéãå€ãã
ãããšã¯å¥œãŸãããªãã[0014] e) The content of ZrO 2 is 0.05 to 2.8% by weight. ZrO 2 has the effect of promoting sintering of mullite sintered bodies, and by containing a certain amount of mullite,
Sinterability is improved, and it is possible to prevent a decrease in corrosion resistance and mechanical strength that occurs when the bulk density is low. This sintering promoting effect is presumed to be due to ZrO 2 being present at the grain boundaries of mullite crystals during the sintering process and promoting mutual diffusion of mullite at the grain boundaries. At the same time,
The presence of ZrO 2 has the effect of suppressing the segregation of the amorphous matrix that occurs at the mullite grain boundaries, and contributes to improving the toughness and creep properties of the mullite sintered body at high temperatures. However, on the other hand,
ZrO 2 also has drawbacks such as reduced durability due to contamination by flying vapors from the heat source or the material to be heat treated at high temperatures, so it is not preferable to have too much ZrO 2 .
ã0015ã ZrO2ã®å«æéã0.05ééïŒ
æªæºã§ãã
ãšäžèšããå¹æãå°ãªããªãã2.8ééïŒ
ãè¶ã
ããšèé£æ§ãèä¹
æ§ãªã©ã®äœäžã倧ãããªã奜ãŸ
ãããªãããã奜ãŸããã¯ãZrO2ã®å«æéã0.1
ã2.5ééïŒ
ãšããã[0015] If the content of ZrO 2 is less than 0.05% by weight, the above-mentioned effects will be reduced, and if it exceeds 2.8% by weight, corrosion resistance, durability, etc. will be greatly reduced, which is not preferable. More preferably, the content of ZrO2 is 0.1
~2.5% by weight.
ã0016ã ïœïŒããå¯åºŠã¯ã2.96ïœïŒcm3以äžãšã
ãã
ããå¯åºŠã2.96ïœïŒcm3ãäžåããšãèé£æ§ã®äœäž
ããæ©æ¢°ç匷床ã®äœäžãªã©ãçãããããããã
å¯åºŠã¯2.96ïœïŒcm3以äžãšããããšãå¿
èŠã§ããã
奜ãŸããã¯3.00ïœïŒcm3以äžããã奜ãŸããã¯3.05
ïœïŒcm3以äžãšããã[0016] f) The bulk density is 2.96 g/cm 3 or more. If the bulk density is less than 2.96 g/cm 3 , the corrosion resistance and mechanical strength will decrease, so it is necessary to set the bulk density to 2.96 g/cm 3 or more.
Preferably 3.00g/ cm3 or more, more preferably 3.05
g/ cm3 or more.
ã0017ã æ¬çºæã®ã ã©ã€ãçŒçµäœã¯ãäŸãã°ä»¥
äžã®ããã«ããŠè£œé ãããã[0017] The mullite sintered body of the present invention is produced, for example, as follows.
ã0018ã åºçºåæãšããŠã¯ãAl2O3ïŒSiO2ïŒ
1.30ã1.85ã§ãããNa2ãK2ãCaOåã³ZrO2
ãèŠå®éããå«æããªãããæãã¯çŒæã«ãã€ãŠ
èŠå®éããæ®çããªãåæã䜿çšããæå¹æåã
åäžã«ååžããŠããç²æ«ãæãŸããããŸãã
ZrO2ã¯ãç²ç æã«ZrO2補ã¡ãã€ã¢ãçšããŠãã
ã®ç£šèç²ãšããŠæ··å
¥ãããã®ã§ããããããã
ã¯ããããããã ã©ã€ãçµæ¶ã圢æãããŠããã
ã®ã«éå®ããããçŒæå·¥çšã§ã ã©ã€ãçµæ¶ã圢æ
ãããã¢ã«ããåã³ã·ãªã«ã®æ··åç©ãŸãã¯ã¢ã«ã
ãåã¯ïŒããã³ã·ãªã±ãŒãã®ååç©ã§ãã€ãŠãã
ããæ¬çºæã§äœ¿çšã§ããäž»èŠãªåºçºåæãšããŠ
ã¯ãäŸãã°ãæ¯è¡šé¢ç©ïŒã20m2ïŒïœã®æçŒçµæ§ã®
äœãœãŒãã¢ã«ãããšé«çŽåºŠããç³ãŸãã¯ç³è±ãšã®
æ··åç©ããã®æ··åç©1300ã1450âã§çŒæããŠã ã©
ã€ããåæããåæãAlåã³Siååç©æº¶æ¶²ãã
å
±æ²æ³ãççŒæ³ãªã©ã«ãã€ãŠèª¿æŽããåæãªã©ã
æããããšãã§ããã[0018] As a starting material, Al 2 O 3 /SiO 2 =
1.30-1.85, Na2O , K2O , CaO and ZrO2
It is desirable to use a raw material that contains only a specified amount of the active ingredient or that only a specified amount remains after firing, and to use a powder in which the active ingredients are uniformly distributed. Also,
ZrO 2 may be mixed as abrasion powder using ZrO 2 media during pulverization. These are not limited to those in which mullite crystals are formed in advance, and may be a mixture of alumina and silica or a compound of alumina and/or silicate in which mullite crystals are formed in the firing process. The main starting materials that can be used in the present invention include, for example, a mixture of easily sinterable low soda alumina with a specific surface area of 2 to 20 m 2 /g and high-purity silica or quartz, and this mixture is sintered at 1300 to 1450°C. Examples include raw materials prepared by synthesizing mullite, and raw materials prepared from Al and Si compound solutions by coprecipitation methods, roasting methods, etc.
ã0019ã æ¬çºæã§ã¯ããŸãåæããå¹³åç²åŸ
ïŒã¹ããŒã¯ã¹ã®æ³åã«åºã¥ãæ²éæ³ãŸãã¯å
éé
æ³ã«ãã枬å®ïŒãéåžž2ÎŒïœä»¥äžã奜ãŸããã¯1.5ÎŒ
ïœä»¥äžãããã«å¥œãŸããã¯0.5ã1.0ÎŒïœã«ãªãã
ãã«ç²ç ãåæ£ãããBETæ³ã«ããæ¯è¡šé¢ç©ïŒ
ã15m2ïŒïœãšããããšã奜ãŸããããã®ç²ç åã³
åæ£å·¥çšã¯ã湿åŒã§è¡ãªãããšãå¹ççã§ããã
ãŽã ãæš¹èãã¢ã«ããçã§å
匵ãããããã«ãçš
ããŠãã¡ããŒãã¢ã«ããããžã«ã³ãã¢è£œãªã©ã®ç²
ç ã¡ãã€ã¢ã«ãŠããŒã«ããŒãªã³ã°ããã°ãããç²
ç æ©ãšããŠã¯ãããŒã«ãã«ãæ¯åãã«ãã¢ããªã
ã·ãšã³ãã«ãé å¿ãã«ãªã©ã䜿çšã§ããç²ç ãšå
æ£ãåæã«è¡ãªãããšãã§ããã2ÎŒïœçšåºŠä»¥äž
ã®åŸ®ç²åæãçšããå Žåã«ã¯ãç²ç å·¥çšãçç¥ã
ãããšãã§ããããåæã®åæ£ãå
åã«è¡ãªãã
æåãã§ããã ãåäžã«ååžããåæãšããããš
ãå¿
èŠã§ããã[0019] In the present invention, first, the raw material has an average particle size (measured by sedimentation method or light transmission method based on Stokes' law) of usually 2 ÎŒm or less, preferably 1.5 ÎŒm.
The particles are ground and dispersed to a particle size of 0.5 to 1.0 ÎŒm or less, preferably 0.5 to 1.0 ÎŒm. Specific surface area 2 by BET method
It is preferable to set it as 15 m <2> /g. It is efficient to carry out this grinding and dispersion process in a wet manner.
Ball milling may be performed using a grinding media made of agate, alumina, zirconia, etc. using a mill lined with rubber, resin, alumina, etc. As a crusher, a ball mill, a vibration mill, an attrition mill, a centrifugal mill, etc. can be used, and crushing and dispersion can be performed simultaneously. When using fine powder raw materials of about 2 ÎŒm or less, the pulverization step can be omitted, but the raw materials must be sufficiently dispersed.
It is necessary to use a raw material whose components are distributed as uniformly as possible.
ã0020ã ç²ç ãŸãã¯ïŒåã³åæ£ãè¡ãªã€ãåæ
ã¯ã次ã«æ圢工çšã§ææã®åœ¢ç¶ã«æ圢ããããæ
圢æ³ãšããŠã¯ãéåžžã®çª¯æ¥è£œåã«çšããããŠãã
æ¹æ³ãé©çšã§ããäŸãã°æ¬¡ã®ãããªæ¹æ³ã§æ圢ã
ãããCIPïŒéæ°Žå§æ圢æ³ïŒã§ã¯ãäžèšåæã«
PVAãªã©ã®æ圢å©å€ãæ°ïŒ
æ·»å ããé ç²ç²äœ
ïŒäž»ãšããŠåŽé§ä¹Ÿç¥æ³ã«ããïŒã調æŽããŠæ圢ã
ããæ圢å§åãšããŠã¯ã0.5ãïŒãã³ïŒcm2çšåºŠã®
å§åã奜ãŸãããæŒåºãæ圢æ³ã®å Žåã¯ãã¡ãã«
ã»ã«ããŒãºãããã¹ããªã³ãPVAãªã©ã®ç²çµæ§
ã«å¯ãã ããŒã¹ãç¶ã®æ圢å©å€ãåŠçåæã«æ··ç·Ž
ããæŒåºãæ©ã«ãŠæ圢ãããé³èŸŒã¿æ圢æ³ã®å Žå
ã¯ãåŠçåæãã¹ã©ãªãŒç¶ãšããŠãç²åºŠã30ã
3000cpãšãªãããã«èª¿æŽããç³èåãªã©ã®æ圢
åãçšããŠæ圢ããæ圢åŸä¹Ÿç¥ããŠæ圢äœãšã
ãããããã®æ圢äœã¯ãçŒæå·¥çšã§ã®çŒæåçž®ã«
ããšã¥ããŠææã®å¯žæ³ããã倧ããå²å¢å¯žæ³ã®åœ¢
ç¶ã«é ãããã[0020] The raw material that has been pulverized and/or dispersed is then molded into a desired shape in a molding step. As the molding method, methods used for ordinary ceramic products can be applied, and for example, the following method is used for molding. In CIP (hydrostatic pressing), the above raw materials
A granulated powder (mainly by spray drying method) to which a few percent of a molding aid such as PVA is added is prepared and molded. The molding pressure is preferably about 0.5 to 2 tons/cm 2 . In the case of extrusion molding, a pasty molding aid with high caking properties such as methylcellulose, dextrin, and PVA is kneaded with the raw material to be processed, and then molded using an extruder. In the case of the cast molding method, the raw material to be treated is in the form of a slurry, and the viscosity is 30~30.
It is adjusted to 3000 cp, molded using a mold such as a plaster mold, and dried after molding to form a molded body. These molded bodies are made into shapes with additional dimensions larger than desired dimensions based on firing shrinkage in the firing process.
ã0021ã 次ãã§æ圢äœã¯ãéæŸé°å²æ°äž1500ã
1750âã®æž©åºŠã§çŒæããããçŒæ枩床ã¯ãåæã®
çš®é¡ãæ圢äœã®æåãæ圢äœã®çŒæ掻æ§ãªã©ã«ã
ãå·Šå³ãããããåžžå§çŒçµã®å Žåã«ã¯ã奜ãŸãã
ã¯ã1550ã1750âãããã«å¥œãŸããã¯1550ã1700
âãšãããçŒçµæž©åºŠã1500âãããäœããšãææ
ã®å¯åºŠãåŸãããã1750âãããé«æž©ã§ã¯ãçµæž
çã§ãªããšå
±ã«ãçµæ¶ç²åŸãç²å€§åãããã匷床
ã®äœäžãå¯åºŠã®äœäžãæããããã«çŒæå·¥çšã§å€
圢ãçãããããªã奜ãŸãããªãã[0021] Next, the molded body is heated to 1500 ~
It is fired at a temperature of 1750â. The firing temperature depends on the type of raw material, the components of the molded body, the firing activity of the molded body, etc., but in the case of pressureless sintering, it is preferably 1550 to 1750°C, more preferably 1550 to 1700°C.
â. If the sintering temperature is lower than 1500°C, the desired density cannot be obtained, and if the sintering temperature is higher than 1750°C, it is not economical and the crystal grain size becomes too coarse, leading to a decrease in strength and density. This is undesirable because deformation tends to occur during the firing process.
ã0022ã æ¬çºæã®ã ã©ã€ãçŒçµäœã«ãã€ãŠããŒ
ã©ãŒããŒã¹ãã«ã³çšããŒã©ãŒãåŸãå Žåã«ã¯ãã
ã®å¯žæ³ã¯ããã«ã³ã®å·Ÿã被ç±åŠçææã®åœ¢ç¶ãé¢
ç©ãããã«ãããééã䜿çšæž©åºŠãªã©ã«ãã€ãŠæ±º
ãŸãããå€åŸ15ã50mmãå€åŸïŒå
åŸïŒ1.2ã
1.5ãé·ãïŒå€åŸïŒ25ã80çšåºŠã§ããããšã奜ãŸ
ãããå
é¢ã¯ãå¿
ãããåã§ããããšã«éå®ãã
ãªãããå€é¢ã¯ã±0.5mm以å
ã®ç²ŸåºŠããã€ãçå
ã§ããããšãæãŸããã[0022] When obtaining a roller for a roller hearth kiln using the mullite sintered body of the present invention, its dimensions depend on the width of the kiln, the shape of the material to be heat treated, the weight per area, the operating temperature, etc. It depends, but the outer diameter is 15~50mm, outer diameter/inner diameter = 1.2~
1.5, length/outer diameter = about 25 to 80 is preferable. Although the inner surface is not necessarily limited to being circular, it is desirable that the outer surface be a perfect circle with an accuracy within ±0.5 mm.
ã0023ã[0023]
ãçºæã®å¹æã æ¬çºæã®ã ã©ã€ãçŒçµäœã¯ã次
ã®ãããªåªããç¹æ§ãæããã
ïŒäžè¬ã«é«æž©ãé«åŒ·åºŠã»ã©ããã¯ã¹ãšãããŠãã
Si3N4ãSiCãªã©ã«æ¯ããé«æž©éæŸé°å²æ°ã§å®å®
ã§ããã
ïŒç±äŒå°çãäœãããç±æŸæ£ãå°ãªããçµæžçã§
ãããç±å¹çãé«ãã
ïŒç±æºã被ç±åŠçææããã®é«æž©ã«ãããé£æ£èž
çºç©ã«ããæ±æã«é«ãèä¹
æ§ã瀺ããé·æéã®äœ¿
çšãå¯èœã§ããã
ïŒ æ¥æ¿ãªæž©åºŠå€åã«èãããèç±è¡ææ§ãæã
ãã
5Si3N4ãSiCãAl2O3ãªã©ã®ã»ã©ããã¯ã¹ã«æ¯ã
匟æ§çãäœããç¹ã«é«æž©ã«ãããŠé©åœã«å€åœ¢ãã
å¿åéäžãããã«ããææ§é äœã§ããã
ïŒã ã©ã€ãçµæ¶ãã¢ã¹ãã¯ãæ¯ã®é«ãéç¶ã§ã網
ç®æ§é äœã圢æããé±æ§ãé«ããã¯ãªãŒãç Žæã
ãã«ããã[Effects of the Invention] The mullite sintered body of the present invention has the following excellent properties. 1 Generally considered to be high-temperature, high-strength ceramics.
Compared to Si 3 N 4 , SiC, etc., it is stable in a high temperature open atmosphere. 2 Low thermal conductivity, less heat dissipation, economical, and high thermal efficiency. 3.It exhibits high durability against contamination by flying vapors from heat sources and heat-treated materials at high temperatures, and can be used for long periods of time. 4. Has thermal shock resistance that can withstand rapid temperature changes. It has a lower elastic modulus than ceramics such as 5Si 3 N 4 , SiC, and Al 2 O 3 and deforms appropriately, especially at high temperatures.
It is a flexible structure that is less susceptible to stress concentration. 6 Mullite crystals are acicular with a high aspect ratio, forming a network structure, having high toughness and being resistant to creep rupture.
ã0024ã æ¬çºæã®ã ã©ã€ãçŒçµäœã¯ãäžèšãã
æ§ãªåªããç¹æ§ãæããé«æž©ã«ãããŠãèä¹
æ§ã«
åªããé«è·éã«èããã®ã§ãèç±æ§éšæãç¹ã«ã
ããŒã©ãŒããŒã¹ãã«ã³çšããŒã©ãŒçãšããŠæçšã§
ããã[0024] The mullite sintered body of the present invention has the above-mentioned excellent properties, has excellent durability, and can withstand high loads at high temperatures, so it can be used as a heat-resistant member, especially,
It is useful as a roller for roller hearth kilns, etc.
ã0025ãã0025ã
ãå®æœäŸã 以äžå®æœäŸã«åºã¥ãæ¬çºæãæŽã«è©³
现ã«èª¬æããã[Examples] The present invention will be explained in more detail based on Examples below.
ã0026ãã0026ã
ãå®æœäŸïŒã å¹³åç²åŸ0.7ÎŒïœã§æ¯è¡šé¢ç©ïŒm2ïŒ
ïœã®99.95ïŒ
Al2O3ãšå¹³åç²åŸ1.5ÎŒïœã®99.9ïŒ
SiO2
ãšãAl2O3ïŒSiO2ïŒ1.34ã«ãªãããïŒKgé
åã
1400âã§çŒæããŠã ã©ã€ãã«åæããåæã«ã
CMCãïŒïŒ
å ãã91ïŒ
Al2O3補ã®ããŒã«ãã«ãš
匷åãžã«ã³ãã¢è£œç²ç çšã¡ãã€ã¢ãçšããŠ48æé
湿åŒã§ç²ç ãåæ£ãããå¹³åç²åŸ0.7ÎŒïœãšãã
åŸãåŽé§ä¹Ÿç¥ã«ããæ圢çšç²äœ2.5KgãåŸãã[Example 1] Average particle size 0.7 ÎŒm and specific surface area 8 m 2 /
g 99.95% Al2O3 and 99.9% SiO2 with average particle size 1.5ÎŒm
and 3 kg of Al 2 O 3 /SiO 2 = 1.34.
Raw materials synthesized into mullite by firing at 1400â,
Add 1% CMC, wet-mill and disperse for 48 hours using a 91% Al 2 O 3 ball mill and reinforced zirconia grinding media to obtain an average particle size of 0.7 ÎŒm, and then spray dry to form a molding powder. Obtained 2.5Kg.
ã0027ã ãã®ç²äœããCIPã«ãã1.5ãã³ïŒcm2ã®
å§åã§ãã€ãç¶ã«æ圢ãã1680âã§ïŒæéçŒæã
ãã[0027] This powder was formed into a pipe shape by CIP at a pressure of 1.5 tons/cm 2 and fired at 1680°C for 3 hours.
ã0028ãã0028ã
ãå®æœäŸïŒã å®æœäŸïŒãšåäžåæãçšãAl2
O3ïŒSiO2ïŒ1.47ãšãªãããïŒKgé
åããæŽã«æ²é
çé
žã«ã«ã·ãŠã ãCaOæç®ã§0.14ïŒ
å ããåŸãå®
æœäŸïŒãšåäžæ¹æ³ã«ãã1650âã§ïŒæéçŒæã
ãã[Example 2] Using the same raw materials as in Example 1, Al 2
After blending 3 kg so that O 3 /SiO 2 =1.47 and further adding 0.14% of precipitated calcium carbonate in terms of CaO, the mixture was calcined at 1650° C. for 3 hours in the same manner as in Example 1.
ã0029ã[0029]
ãå®æœäŸïŒã å®æœäŸïŒãšåäžåæãçšããŠAl2
O3ïŒSiO2ïŒ1.62ãšãªãããïŒKgé
åããããã«æ¯
è¡šé¢ç©10m2ïŒïœãå¹³åç²åŸ0.4ÎŒïœã®99.9ïŒ
ZrO2埮
ç²ã2.5ééïŒ
å ããåŸã匷åãžã«ã³ãã¢è£œã®ã
ãŒã«ãã«ãšç²ç çšã¡ãã€ã¢ãçšããŠ48æé湿åŒã§
ç²ç ãåæ£ããå¹³åç²åŸ0.55ÎŒïœãšããããã®åŸ
ã®å·¥çšã¯ãå®æœäŸïŒãšåæ§ã§ã1630âã§ïŒæéçŒ
æããã[Example 3] Using the same raw materials as in Example 1, Al 2
After blending 3 kg so that O 3 /SiO 2 = 1.62 and adding 2.5% by weight of 99.9% ZrO 2 fine powder with a specific surface area of 10 m 2 /g and an average particle size of 0.4 Όm, a ball mill made of reinforced zirconia and a grinding medium were used. The powder was wet-pulverized and dispersed for 48 hours to give an average particle size of 0.55 Όm. The subsequent steps were the same as in Example 1, and firing was performed at 1630°C for 5 hours.
ã0030ãã0030ã
ãå®æœäŸïŒã Al2O3ïŒSiO2ïŒ1.80ãAl2O3ãš
SiO2ã®åèšé99.2ééïŒ
ã®é»èã ã©ã€ãã®åŸ®ç²30
ééïŒ
åã³å®æœäŸïŒã®Al2O3ãšSiO2ãAl2O3ïŒ
SiO2ïŒ1.55ãšãªãããé
åãããã®70ééïŒ
ãã
ãªãåæã«ãæŽã«å¹³åç²åŸ0.7ÎŒïœã®99.0ïŒ
ZrO2埮
ç²ã1.5ééïŒ
å ããåŸã湿åŒã«ãŠæš¹è補ãã«ã§
99.5ïŒ
Al2O3補ã¡ãã€ã¢ãçšããŠãæ¯åã«ããã
12æéã§å¹³åç²åŸ1.1ÎŒïœãšãªãããç²ç ããåæ£
ãããã[Example 4] Al 2 O 3 /SiO 2 = 1.80, Al 2 O 3
Electrofused mullite fine powder 30 with a total amount of SiO2 99.2% by weight
Weight% and Al 2 O 3 and SiO 2 of Example 1
After adding 1.5% by weight of 99.0% ZrO 2 fine powder with an average particle size of 0.7 ÎŒm to the raw material consisting of 70% by weight of SiO 2 = 1.55, it was wet-processed in a resin mill.
Using 99.5% Al 2 O 3 media, by vibration,
The mixture was ground and dispersed to an average particle size of 1.1 ÎŒm in 12 hours.
ã0031ã ãã®ã¹ã©ãªãŒã«çé¢æŽ»æ§å€ã埮éæ·»å
ããç²åºŠã250cpã«èª¿æŽããŠãïŒKgïŒcm2ã®å§åã
ãããŠãç³èåã«é³èŸŒã¿æ圢ãã也ç¥åŸ1650âã§
ïŒæéçŒæããã[0031] A small amount of surfactant was added to this slurry, the viscosity was adjusted to 250 cp, and a pressure of 2 Kg/cm 2 was applied to cast it into a plaster mold, and after drying, it was baked at 1650° C. for 3 hours.
ã0032ã[0032]
ãå®æœäŸïŒã Alåã³Siååç©ã®æº¶æ¶²ããç±å
解æ³ã§åæãä»®çŒããAl2O3ïŒSiO2ïŒ1.80ã®Alâ
Siã¹ããã«åæç²æ«ã«Y2O3ã0.3ïŒ
ãšé·ç³ãäž»æ
åïŒNaãïŒ2ã»Al2O3ã»6SiO2ããNa2ïŒK2
ã0.1ééïŒ
ãšãªãããæ·»å é
åããå¹³åç²åŸ
0.6ÎŒïœã®99.9ïŒ
ZrO2埮ç²ã0.5ééïŒ
æ·»å ããåŸã
å®æœäŸïŒãšåäžæ¹æ³ã§å¹³åç²åŸ0.6ÎŒïœã«ç²ç ãã
åæ§ã«åŠçãæ圢ããŠã1590âã§ïŒæéçŒæã
ãã[Example 5] Alâ with Al 2 O 3 /SiO 2 =1.80 synthesized and calcined from a solution of Al and Si compounds by thermal decomposition method
Si spinel raw material powder with 0.3% Y 2 O 3 and feldspar [main components (Na, K) 2 Oã»Al 2 O 3ã»6SiO 2 ] was added to Na 2 O + K 2
Addition and blending so that O is 0.1% by weight, and the average particle size
After adding 0.5 wt% of 0.6 ÎŒm 99.9% ZrO2 fine powder,
Grinded to an average particle size of 0.6 ÎŒm in the same manner as in Example 3,
It was treated and molded in the same manner and fired at 1590°C for 6 hours.
ã0033ãã0033ã
ãå®æœäŸïŒã å®æœäŸïŒã®ã ã©ã€ã40ééïŒ
åã³
ã¢ã«ãã99.9ïŒ
SiO2ãšãAl2O3ïŒSiO2ïŒ1.80ã«ãª
ãããæ··åããç²æ«60ééïŒ
ãããªãåæã«æ²é
çé
žã«ã«ã·ãŠã ãCaOæç®ã§0.05ééïŒ
åã³æ°Žé
ž
åãžã«ã³ããŠã ãZrO2æç®ã§2.0ééïŒ
å ããå®
æœäŸïŒãšåæ§ã®æ¹æ³ã«ããçŒæ枩床1720âã§ïŒæ
éçŒæããã[Example 6] Precipitated calcium carbonate was added to a raw material consisting of 60% by weight of powder obtained by mixing 40% by weight of mullite and 99.9% alumina SiO 2 in Example 4 so that Al 2 O 3 /SiO 2 = 1.80 was mixed with precipitated calcium carbonate in terms of CaO. 0.05% by weight and 2.0% by weight in terms of ZrO 2 of zirconium hydroxide were added, and the mixture was fired in the same manner as in Example 4 at a firing temperature of 1720°C for 2 hours.
ã0034ãã0034ã
ãå®æœäŸïŒã Alåã³Siååç©ã®æº¶æ¶²ããç±å
解æ³ã§åæãä»®çŒããAl2O3ïŒSiO2ïŒ1.47ã®ã ã©
ã€ãç²æ«ãçšããããã«å¹³åç²åŸ0.6ÎŒïœã®99.9ïŒ
ZrO2埮ç²ã1.0ééïŒ
æ·»å ããŠãå®æœäŸïŒãšåäž
æ¹æ³ã«ããçŒæäœã補é ããã[Example 7] A mullite powder of Al 2 O 3 /SiO 2 = 1.47 synthesized and calcined from a solution of Al and Si compounds by a thermal decomposition method was used.
A fired body was produced in the same manner as in Example 5 by adding 1.0% by weight of ZrO 2 fine powder.
ã0035ãã0035ã
ãæ¯èŒäŸïŒã Al2O3ïŒSiO2ïŒ1.18ãç²ç æéã
15æéãšãã以å€ã¯ãå®æœäŸïŒãšåæ§ã«ããŠçŒæ
äœã補é ããã[Comparative example 1] Al 2 O 3 /SiO 2 = 1.18, grinding time
A fired body was produced in the same manner as in Example 1, except that the heating time was 15 hours.
ã0036ãã0036ã
ãæ¯èŒäŸïŒã å®æœäŸïŒã®ã ã©ã€ãã99.6ïŒ
ã¢ã«
ããç²æ«ãã«ãªãªã³ïŒäž»æåAl2O3ã»SiO2ã»2H2
ïŒåã³é·ç³ãçšããŠAl2O3ïŒSiO2ïŒ1.27ãšãªã
ããã«é
åãã91ïŒ
Al2O3補ã®ããŒã«ãã«ãšç²ç
çšã¡ãã€ã¢ãçšããŠã48æé湿åŒã§ç²ç åŸãè±
æ°Žã也ç¥ãè¡ãªããããã«å¢ç²å€ãå ããŠæ··ç·Ž
ããååãšããæŒãåºãæ圢ãè¡ãªã€ãåŸã1700
âã§ïŒæéçŒæããã[Comparative Example 2] Mullite of Example 4, 99.6% alumina powder, kaolin (main component Al 2 O 3ã»SiO 2ã»2H 2
O) and feldspar to give Al 2 O 3 /SiO 2 = 1.27, and wet-pulverized for 48 hours using a 91% Al 2 O 3 ball mill and crushing media, then dehydrated and dried. After adding a thickener and kneading to form a clay and extrusion molding,
It was baked at â for 3 hours.
ã0037ãã0037ã
ãæ¯èŒäŸïŒã ZrO21.5ééïŒ
ãMgO1.3ééïŒ
åã³Fe2O30.3ééïŒ
ãå ãã以å€ã¯ãå®æœäŸïŒãš
åäžæ¹æ³ã§ç²ç ããåŸãæ¯èŒäŸïŒãšåäžæ¹æ³ã§æ
圢ãçŒæããã[Comparative Example 3] ZrO 2 1.5% by weight, MgO 1.3% by weight
The powder was pulverized in the same manner as in Example 1, except that 0.3% by weight of Fe 2 O 3 was added, and then molded and fired in the same manner as in Comparative Example 2.
ã0038ãã0038ã
ãæ¯èŒäŸïŒã Al2O3ïŒSiO2ïŒ1.47ãšããé·ç³ã
Na2ãšK2ã®åèšéã0.24ééïŒ
ãšãªãããã«
é
åãã以å€ã¯ãå®æœäŸïŒãšåæ§ã«ããŠçŒæäœã
補é ããã[Comparative Example 4] Al 2 O 3 /SiO 2 = 1.47, feldspar
A fired body was produced in the same manner as in Example 1, except that the total amount of Na 2 O and K 2 O was 0.24% by weight.
ã0039ãã0039ã
ãæ¯èŒäŸïŒã é
åæ¯ãå€ããŠAl2O3ïŒSiO2ïŒ
1.78ãšããZrO2æ·»å éã3.5ééïŒ
ãšãã以å€ã¯
æ¯èŒäŸïŒãšåäžæ¹æ³ã«ããçŒæäœã補é ããã[Comparative Example 5] Al 2 O 3 /SiO 2 = by changing the blending ratio
1.78, and a fired body was produced in the same manner as in Comparative Example 2 except that the amount of ZrO 2 added was 3.5% by weight.
ã0040ãã0040ã
ãæ¯èŒäŸïŒã å®æœäŸïŒã§çšããã ã©ã€ãã97ïŒ
Al2O3補ã®ãã«ãšç²ç ã¡ãã€ã¢ãçšããŠ120æé
ç²ç ãããã®åŸã¯å®æœäŸïŒãšåæ§ã«ããŠçŒæäœã
補é ããã[Comparative Example 6] 97% mullite used in Example 4
The powder was ground for 120 hours using an Al 2 O 3 mill and grinding media, and thereafter a fired body was produced in the same manner as in Example 1.
ã0041ã[0041]
ãè©ŠéšäŸã äžèšã®å®æœäŸåã³æ¯èŒäŸã«ãã補é
ãããã€ãç¶ã®çŒæäœã«ã€ããŠãå é寿åœè©Šéšå
ã³èä¹
è©Šéšãè¡ãªã€ããçŒæäœã®çµæåã³ããå¯
床ãè¡šïŒã«ãè©Šéšçµæãè¡šïŒã«ç€ºããè©Šéšæ¹æ³
ã¯ã以äžã«ç€ºãéãã§ããã
âå é寿åœè©ŠéšïŒ
å€åŸ21mmãå
åŸ16mmãé·ã450mmã®ãã€ããè©Š
æãšããæ¯ç¹éè·é¢300mmã«æ¯ç¹ãèšãããã®é
ãçå
枩床1400âåã¯1460âã«ä¿æãã䞡端ãç
å€ã«äœçœ®ããããè©Šæãèšçœ®ãããã®äžå€®éšã«è·
éãå ããŠããã€ããç ŽæããããŸã§ã®æéãæ±
ããããªãããã€ãã¯ïŒåããšã«åå転ãããã
è¡šïŒã«ã¯ãè·éãåäœé¢ç©åœãã®å¿åã§ç€ºããã
ããã¯æ¬¡ã®èšç®åŒã«ããšã¥ããã®ã§ããã[Test Example] Accelerated life tests and durability tests were conducted on the pipe-shaped fired bodies produced in the above Examples and Comparative Examples. The composition and bulk density of the fired body are shown in Table 1, and the test results are shown in Table 2. The test method is as shown below. â Accelerated life test: A pipe with an outer diameter of 21 mm, an inner diameter of 16 mm, and a length of 450 mm is used as a sample. Support points are set at a distance of 300 mm between the supports, and the temperature inside the furnace is maintained at 1400°C or 1460°C, with both ends located outside the furnace. A sample was set up so that the pipe would break, a load was applied to the center of the pipe, and the time required for the pipe to break was determined. Note that the pipe was rotated half a rotation every 5 minutes.
Table 2 shows the load in terms of stress per unit area, which is based on the following calculation formula.
ã0042ã åäœé¢ç©åœãã®å¿åïŒKgïœïŒcm2ïŒïŒ
8wlïŒïŒD4âd4ïŒÏïŒïŒ€
ïŒè·éãïœïŒã¹ãã³é·ãïŒå€åŸãïœïŒå
åŸ
ãã®ãã¹ãæ¡ä»¶ã¯ãå®çšãã«ã³ã§ã®äžæ¬åœãã®ã
ãŒã©ãŒã«ãããè·éã®ïŒãïŒåã®è·éãšèŠç©ã
ããå®çšãã«ã³ã§ã¯104å以äžã®å¯¿åœãäºæž¬ãã
ãããã®ããã100å以äžã®å¯¿åœãããå Žåã«ã¯ã
ããé«æž©ãŸãã¯ããé«è·éã®äœ¿çšãå¯èœãšããã
ã®ãšæãããã
âèä¹
è©ŠéšïŒ
éæ²¹ççŒã®ã»ã©ããã¯ã¹çŒæçã®ææ¥äžã®çå
1500âã®é°å²æ°äžã«å€åŸ21mmãå
åŸ16mmãé·
ã150mmã®ãã€ãè©Šæãæ¿å
¥ããïŒã±æä¿æãã
åŸã宀å
ã«åãåºãããã®æ²ã匷床ãååŒã«åºã¥
ããŠèšæž¬ãïŒã¹ãã³100mmïŒããã¹ãåã®åŒ·åºŠãšã®
匷床çŸåçã§ç€ºããã[0042] Stress per unit area (Kgf/cm 2 )=
8wl/(D 4 â d 4 )Ï/D W: load, l: span length, D: outer diameter, d: inner diameter This test condition is based on the load applied to one roller in a practical kiln, which is 3 to 6 It is estimated that the load will be twice as long, and the life of a practical kiln is expected to be more than 10 4 times longer. Therefore, if the lifespan is more than 100 minutes,
It is believed that it enables use at higher temperatures or higher loads. âDurability test: Inside of a heavy oil-burning ceramics firing furnace during operation
A pipe sample with an outer diameter of 21 mm, an inner diameter of 16 mm, and a length of 150 mm was inserted into an atmosphere at 1500°C, held for one month, then taken out indoors, and its bending strength was measured based on the previous formula (span 100 mm) and tested. The intensity is expressed as a percentage of the previous intensity.
ã0043ãã0043ã
ãè¡šïŒã â â â äºã®ç² 0027 â â â [Table 1] â â â Turtle shell [0027] â â â
ã0044ãã0044ã
ãè¡šïŒã
â â â äºã®ç² 0028 â â â
è¡šïŒããæ¬çºæã®ã ã©ã€ãçŒçµäœãçšããããŒã©
ãŒããŒã¹ãã«ã³çšããŒã©ãŒã¯ãé«æž©ã§ã®é«è·éã®
䜿çšã«èããé·æé䜿çšåŸã«ãããŠãé«åŒ·åºŠãæ
ããããšãæããã§ããã[Table 2] â â â Turtle shell [0028] â â â From Table 2, rollers for roller hearth kilns using the mullite sintered body of the present invention can withstand use at high temperatures and high loads, and even after long-term use. It is clear that it has high strength.
Claims (1)
ééïŒ ä»¥äžã CaO 0.2ééïŒ ä»¥äžã Na2åã³K2ã®åèšé0.2ééïŒ ä»¥äžã䞊
ã³ã« ZrO2 0.05ã2.8ééïŒ ã§ãããAl2O3ïŒSiO2ïŒã¢ã«æ¯ïŒïŒ1.30ã1.85ãã
ãå¯åºŠ2.96ïœïŒcm3以äžã§ããã ã©ã€ãçµæ¶ãäž»äœ
ãšããã ã©ã€ãçŒçµäœã[Claim 1] i Total amount of Al 2 O 3 and SiO 2 97.0
% by weight or more, CaO 0.2% by weight or less, total amount of Na 2 O and K 2 O 0.2% by weight or less, and ZrO 2 0.05-2.8% by weight, Al 2 O 3 /SiO 2 (molar ratio) = 1.30- 1.85, a mullite sintered body mainly composed of mullite crystals with a bulk density of 2.96 g/cm 3 or more.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2418874A JPH04209753A (en) | 1990-12-27 | 1990-12-27 | Mullite sintered compact |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2418874A JPH04209753A (en) | 1990-12-27 | 1990-12-27 | Mullite sintered compact |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP59193289A Division JPS6172989A (en) | 1984-09-14 | 1984-09-14 | Ceramic roller and manufacture thereof |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH04209753A JPH04209753A (en) | 1992-07-31 |
JPH0585499B2 true JPH0585499B2 (en) | 1993-12-07 |
Family
ID=18526629
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2418874A Granted JPH04209753A (en) | 1990-12-27 | 1990-12-27 | Mullite sintered compact |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH04209753A (en) |
-
1990
- 1990-12-27 JP JP2418874A patent/JPH04209753A/en active Granted
Also Published As
Publication number | Publication date |
---|---|
JPH04209753A (en) | 1992-07-31 |
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