Ukukhetha I-Crucible Material Elungile Yekuncibilika Kwezinga Eliphezulu-

1. Isingeniso

Ezindaweni ezifunwayo, eziphakeme-zezensimbi zesimanje, isayensi yezinto ezithuthukisiwe, ukukhiqizwa kwengilazi okukhethekile, ukutshala imali okunembayo, kanye{1}}nokuhlanganiswa kwamakhemikhali wezinga lokushisa eliphezulu, izingcezu zamathuluzi ezimbalwa ezibucayi kakhulu, noma zingaphansi kwesijeziso esinzima sokusebenza, njenge-industrial crucible. Isebenza njengesitsha esiyinhloko, esibalulekile esithwala izinsimbi ezincibilikisiwe, usawoti oncibilikisiwe osebenzayo, ama-aggressive fluxes, kanye{3}}nokuncibilika okuphezulu{4}}kwe-ceramic ehlanzekile, i-crucible kumele ihlale ibekezelela amazinga okushisa okusebenza aqhumayo akhuphuka adlule ku-1500 degrees Celsius ngenkathi ngesikhathi esifanayo igcina ukuqina, igcina ikhemikhali iqinile. ukungenzi lutho ngaphansi kokucindezelwa. Ukukhetha into efanelekile ye-crucible yenqubo ethile yokushisa akuwona neze umsebenzi omncane wobunjiniyela; ukukhetha okungalungile kwempahla kungaholela ngokuqondile ekuhlulekeni kwesakhiwo okuyinhlekelele, ukuchitheka kwensimbi encibilikisiwe okuyingozi, umonakalo omkhulu wesithando somlilo, nokungcoliswa kwenqwaba okulimaza ngokushesha konke ukukhiqizwa kwezimboni.

Njengoba izinqubo zesimanje zezimboni ziqhubekela phambili ziqhubekela phambili zibheke emikhawulweni yokushisa ephezulu, izidingo eziqinile zokuhlanzeka kwamakhemikhali, kanye nokwakheka kwengxubevange okushubile, ukwazi amanuances wemidiya etholakalayo yokuqukatha sekuyinto ebalulekile kuma-metallurgists kanye nonjiniyela abacubungula ngokufanayo. I-crucible ngayinye inephrofayili ehlukile, ekhetheke kakhulu yezimpawu ezishisayo, zemishini, kanye namakhemikhali ezisho ukufaneleka kwayo okunembile kwezinhlelo ezithile zokukhiqiza. Ukuthi unjiniyela uncibilikisa izinsimbi eziyigugu endaweni encane yobuciko, ekhiqiza{2}}ama-superalloy aphezulu ama-aerospace turbine blades, noma ukukhulisa ama-single{3}}crystal sapphire boules esithandweni esikhethekile se-vacuum, ukukhetha kwe-crucible kudinga impumelelo yokugcina noma ukwehluleka okubizayo. Lesi sihloko esibanzi sihlola izici eziyinhloko zokukhetha, izigaba zezinto ezibalulekile, izinqubo ezingcono kakhulu zokusebenza, kanye{5}}nezinhlelo zokusebenza eziqondile zomkhakha eziqondisa ochwepheshe ekukhetheni i-crucible efanele{6}}yemisebenzi yokuncibilika kwezinga lokushisa eliphezulu.

2. Izinto Ezibalulekile Ekukhetheni Izinto Ezisetshenziswayo

Izakhiwo ezishisayo kanye nokumelana nokushaqeka kwe-Thermal

Ukucatshangelwa okuphambili lapho uhlola noma iyiphi-izinga lokushisa eliphakeme iphrofayili yayo enemininingwane yokusebenza kwe-thermal. I-crucible efanelekile kufanele ibe nendawo yokuncibilika kanye nomkhawulo wokuthamba ophakeme kakhulu kunezinga lokushisa eliphakeme lokusebenza leshajethi encibilikisiwe equkethwe kuyo. Kodwa-ke, ukuba nendawo ephezulu yokuncibilika kukodwa akwanele ngokuphelele ekufuneni izindawo zezimboni. Ukumelana nokushaqeka kokushisa{4}kuchazwa njengekhono lezinto ezikwazi ukumelana nokushintshashintsha kwezinga lokushisa okusheshayo, okwedlulele ngaphandle kokuqhekeka, ukuqhekeka, noma ukuphuka komshini okuyinhlekelele{5}}kubalulekile ngokufanayo. Lapho i-crucible ebandayo iphonswa kungazelelwe esithandweni sokungeniswa esishisayo noma esithandweni sokumelana, noma lapho impahla encibilikisiwe ithululelwa kuyo noma iphuma kuyo ngokushesha, ama-gradients amakhulu ashisayo akhula ngokushesha ezindongeni eziwugqinsi ze-crucible. Izinto eziqukethe ama-coefficients okunweba okushisayo okuphansi kanye nokusebenza okuphezulu kwe-thermal, njengezinhlanganisela ezikhethekile zegraphite ne-silicon carbide, zihamba phambili ekuphatheni imijikelezo yokushisa esheshayo, kuyilapho i-monolithic oxide ceramics idinga izivumelwano zokushisa ezihamba kancane kancane zangaphambi{8}{8}}ezilawulwa ngokuqinile ukuze kuvinjelwe ukwehluleka ukushaqeka kokushisa.

Ukuhambisana Kwekhemikhali kanye Nokusebenza kabusha

Emazingeni okushisa aphakeme, i-chemical thermodynamics ibeka ukuthi ama-athomu asebenze ngendlela engavamile, akhulise ngokuphawulekayo amathuba nezinga le-kinetic lokusabela kwamakhemikhali okwenzeka phakathi kweshajethi encibilikisiwe nodonga lwangaphakathi lwe-crucible. I-crucible esebenza ngamakhemikhali ingakhipha ukungcola okungafuneki ngokuqondile ekuncibilikeni, iguqule kakhulu i-alloy chemistry futhi yonakalise izakhiwo zikagesi noma zemishini, kuyilapho ukuncibilika okunamandla kungase kugugudeke, kuncibilike, noma kugxumeke izindonga zomkhumbi, okuholela ekuhlulekeni kwesakhiwo ngaphambi kwesikhathi. Ngakho-ke, ukuqonda ukuhambisana kwamakhemikhali kuyisidingo esiphelele. Ukuncibilika kwe-acidic, njenge-silica{3}}izibuko ezicebile nama-slags ane-asidi, kudinga izinto zokuvikela ezine-acidic noma ezingathathi hlangothi njenge-quartz ehlanganisiwe noma{4}}i-alumina ehlanzekile, kuyilapho ama-fluxes aqinile, izinsimbi zomhlaba ezine-alkaline, nama-alloys ensimbi asebenzayo adinga izinto eziyisisekelo zokuphikisa njenge-magnesia noma i-zirconia ezinzile ngokugcwele. Ukukhetha i-crucible engasebenzi ngamakhemikhali kuqinisekisa kokubili ukuhlanzeka kwamakhemikhali komkhiqizo wokugcina oqinisiwe kanye nempilo enwetshiwe yokusebenza yomkhumbi othwalayo ngokwawo.

3. Izinto Ezibalulekile Ezimbaxakayo kanye Nezicelo Zazo

I-Graphite ne-Carbon-Izikhonkwane Ezisekelwe

Inhlanganisela ye-graphite nekhabhoni{0}}ehlanganisiwe ye-silicon carbide imelela ezinye zezinketho ezisetshenziswa kakhulu nezibizayo{1}}ezisebenzayo ze-crucible ekusebenzeni okujwayelekile kwe-Foundry,-i-ferrous metallurgy, nezinkundla zokucobelelana ngolwazi zokuncibilika. I-graphite inikeza i-thermal conductivity engavamile, evumela ukushisa okuvela esithandweni ukuthi kudlulise ngokushesha nangokufanayo ekushajeni okuqinile, okunciphisa kakhulu izikhathi zokuncibilika okuphelele futhi kwehlisa ukusetshenziswa kwamandla jikelele. Ngaphezu kwalokho, i-graphite inamandla amakhulu ngokumangalisayo emishini emazingeni okushisa aphakeme kanye nokumelana okukhethekile nokushaqeka okushisayo, okuyivumela ukuthi imelane nokuphathwa kwe-Foundry. I-graphite crucible ifaneleka ngokukhethekile-ukuncibilikisa ithusi{7}ama-alloys asekelwe, ithusi, ithusi, i-aluminium, nezinsimbi ezihlukahlukene eziyigugu. Kodwa-ke, ngenxa yokuthi i-elemental carbon iyi-ejenti yokunciphisa eqinile futhi ifakwa oksijini kalula emoyeni we-ambient emazingeni okushisa aphezulu, le mikhiqizo ivamise ukugqunywa ngemicwebe ecwebezelayo yangaphandle{9}}ye-oxidation noma isetshenziswe ngokukhethekile ngaphakathi kwe-atmospheres elawulwayo, kumagumbi evacuum, noma amaziko okungenisa ukuze kuvinjelwe ukuwohloka ngaphambi kwesikhathi.

I-Alumina ne-Oxide Ceramic Crucibles

Lapho{0}}ukuncibilika okuhlanzekile kudingekile-njengokulungiswa kwama-nickel akhethekile{2}ama-superalloy asekelwe, izitsha ze-elekthronikhi ezithuthukisiwe, izinto ze-nuclear, noma{3}}amasampula okuhlaziya elabhorethri yokuhlanzeka okuphezulu{4}izinto ze-oxide ceramic crucible ziyindinganiso yomkhakha engenakuphikiswa. -Iziphambano ze-alumina ezihlanzekile (i-aluminium oxide) eziphakeme zinikeza ukungabi namakhemikhali okuvelele, izici ezinhle kakhulu zokuvala ugesi, nokumelana okuphezulu ne-oxidation kufika cishe ku-1800 degrees Celsius. Ezindaweni zamakhemikhali ezidingeka kakhulu ezihlanganisa ama-slags ayisisekelo kakhulu, izinsimbi ezincibilikisiwe ezisebenzayo, noma usawoti obolayo, i-magnesia (i-magnesium oxide) noma i-yttria{9}}i-zirconia crucibles ezinzile iyasetshenziswa. I-alumina {{11}ebaselwe kahle, ephezulu{12}}ehlanzekile iqinisekisa ukungcoliswa okuncane kwe-ionic yokuncibilika, okuyenza ibe intandokazi ngokuphelele phakathi kosokhemisi abahlaziyayo, i-metallurgists, nososayensi bezinto ezibonakalayo abangakwazi ukubekezelela ukulandelela ukungcola kwensimbi ekuncibilikeni kwabo{13}okunemba okuphezulu.

I-Refractory Metal Crucibles

Ezinhlelweni zokusebenza-eziphezulu{1}}ezincibilikisa izinga lokushisa ezeqa ngokuphelele imikhawulo yokusebenza ye-ceramics yendabuko ne-graphite, izinsimbi ze-refractory metal crucibles zibalulekile. Izinto ezifana ne-platinum, i-molybdenum, i-tungsten, ne-tantalum zenziwe zaba imiklamo{3}}esebenza kahle kakhulu yemisebenzi ekhethekile yezimboni kanye nocwaningo oluthuthukisiwe. Ama-crucible eplatinamu asetshenziswa emhlabeni wonke ekwenziweni kwengilazi ebonakalayo, ukuhlaziya okushisayo, kanye nokulungiswa{5}}kwezinto ezibonakalayo ezihlanzekile neze-laser ngenxa yokumelana kwazo ngokuphelele{6}}ne-oxidation ephezulu yezinga lokushisa nokuhlaselwa kwamakhemikhali ngama-molten fluxes amaningi. Ngaleso sikhathi, i-tungsten ne-molybdenum crucibles zibalulekile ekuncibilikiseni izinsimbi eziphikisayo, amafutha enuzi, kanye nokukhula{8}}icrystal sapphire noma i-semiconductor silicon boules eyodwa, nakuba ngokuvamile zidinga izindawo ezikhethekile zokuvala i-vacuum noma igesi engasebenzi ukuze kuvinjwe izinga lokushisa eliphezulu eliyinhlekelele-.

4. Ukufanisa Izikhonkwane Nemisebenzi Ethize Yokuncibilika

I-Melting Non{0}}Alloys Esansimbi Nezinsimbi Eziyigugu

Indawo ethile yokusebenza isho izimfuneko zezinto ezibonakalayo ezingezona-ezitholakalayo nensimbi eyigugu. Lapho kuncibilikiswa ama-alloys egolide, isiliva, i-platinum, i-palladium, noma ithusi{2}}, izinto ezibakhathazayo kakhulu ukulahlekelwa kwensimbi ngenxa yokumuncwa, ukuxutshwa kwe-oxidation, nokungcoliswa kwamakhemikhali okungafuneki. I-clay-i-graphite noma i-silicon carbide crucibles ivame ukukhethwa ukuze incibilike ngobuningi bethusi, ithusi, nethusi ngenxa yokuqina kwayo kokusebenza nokusebenza okuhle kakhulu kokushisa. Ukuze uthole-insimbi eyigugu emsulwa ephezulu kanye namalabhorethri okuhlola okuhlaziya,{7}}i-fireclay ehlanzekile noma iziphambano ze-silica ezihlanganisiwe zisezingeni. Kule misebenzi entekenteke,{9}}yenani eliphakeme, i-crucible kufanele ibe nendawo yangaphakathi{10}}engenazimbobo, ecwebezelayo ukuze kuvinjelwe amaconsi amancane ensimbi eyigugu encibilikisiwe ukuthi anganamatheli unomphela ezindongeni, okuqinisekisa ukutholakala okuphezulu kwensimbi ngesikhathi sokuthululwa.

I-Ceramics Ethuthukisiwe, Ingilazi, Nezinsimbi Ezisebenzayo

Emikhakheni ethuthukisiwe yokukhiqiza, efana nobunjiniyela be-aerospace, ugesi, kanye nokukhiqizwa kwengilazi okukhethekile, imisebenzi yokuncibilika ivame ukubhekana nezimo ezidlulele, ezinolaka kakhulu. Ukuncibilika kwe-titanium esebenzayo, i-zirconium, noma ama-alloys akhethekile aphezulu-i-entropy alloy idinga i-crucible engeke isabele ngamakhemikhali ngokushaja okuncibilikisiwe ukuze kwakhe izinhlanganisela ze-intermetallic brittle, ezingathandeki. Lapha, amasu ayisipesheli afana nokuncibilika okubandayo-okufakwe odongeni (okuvame ukubizwa ngokuthi ukuncibilika kogebhezi) asetshenziswa ngempumelelo, lapho amanzi{4}}i-crucible yensimbi epholile igcina ungqimba "lwekhanda" oluncane, oluqandisiwe lwensimbi eqinile ngokwayo njengesivimbeli sangempela, siqeda ngokuphelele ukusebenzisana kwamakhemikhali phakathi komkhumbi. Ngokuncibilika kwengilazi nokukhula kwekristalu okubonakalayo, iplatinamu noma{6}}izinto ezicwebezelayo ze-iridium crucibles zikhethwa ukuze kuvinjelwe izikhungo zombala ezingafuneki, ukwakheka kwamabhamuza, noma ukucwiliswa kwamakhemikhali okungehlisa isithunzi izici zokudlulisa amehlo zomkhiqizo wokugcina.

5. Ukunakekela, Ukuphatha, kanye Nezinqubo Ezinhle Zokusebenza

Ngaphambi-Amaphrothokholi Okushisa Ne-Anealing

Ngisho nekhwalithi ephezulu-, i-crucible ebiza kakhulu ingase yehluleke ngokuyinhlekelele uma ingaphansi kokuphathwa ngendlela engafanele noma ukuthunywa okusheshayo. Ukumuncwa komswakama kuyisitha esiyinhloko, esithulile seziqukathi ze-refractory neze-ceramic; ama-molecule wamanzi amancane avaleleke ekujuleni kwe-microstructure enezimbotshana anganwebeka ngokushesha abe{2}}nomusi wokucindezela okukhulu lapho ishiswa, okubangele ukuthi i-crucible iqhekeke, iphaphalaze, noma iphihlike ngamandla ngaphakathi kwesithando somlilo. Ngakho-ke, izimiso eziqinile zangaphambi{4}}zokushisa-ngokuvamile ezibandakanya amazinga okushisa angasheshi, alawulwa kakhulu afika ku-200 degrees Celsius alandelwe ukucwiliswa kwe-thermal okuqinile{7}}ayisibopho esiqinile ngaphambi kokuletha noma iyiphi i-ceramic noma i-bod crucible ifike ezingeni lokushisa eligcwele lokusebenza. Ukunakekela okufanayo kufanele kuthathwe ngesikhathi sezigaba zokupholisa ukuze kuvinjwe ukuphuka kokushaqeka okushisayo okubangelwa uhlaka olusheshayo, ukuvula izivalo zesithando somlilo ngaphambi kwesikhathi, noma ukubeka izinsimbi ezishisayo kukhonkolo waphansi obandayo.

Ukuhlola, Ukuhlanza, kanye Neziqondiso Zokugcina

Ukukhulisa ubude besikhathi sokusebenza nokuphepha{0}}kwezinga lokushisa eliphezulu kudinga izindlela zokunakekela eziqinile, eziqondile. Ama-opharetha kufanele enze ukuhlola okujulile okubonakalayo futhi{2}}okungonakalisi ngaphambi kwawo wonke umjikelezo wokuncibilika, ahlole ngokucophelela ukuqhekeka kwemigqa yezinwele, ukuncipha kodonga lwasendaweni, ukuguguleka kwamakhemikhali, noma ukwakheka kwe-slag. Ama-crucibles kufanele ahlanzwe ngomshini noma ngamakhemikhali phakathi kokuncibilika ukuze kususwe insalela ye-slag engase ihlanganyele kanzima nezindleko ezilandelayo. Ngaphezu kwalokho, ukugcinwa okufanele endaweni eyomile, elawulwa yisimo sezulu{5}kubalulekile ukuze kuvinjelwe ukunqwabelana komswakama ngesikhathi sokuphumula. Ngokunamathela ngokuqinile kule mihlahlandlela yokuphatha eneziyalo, izikhungo ziqinisekisa ukuphepha okuphezulu komsebenzisi, zinqanda ukwehluleka kokuqukatha okumba eqolo, futhi zithuthukise zonke izindleko{7}}zokusebenza kahle{8}}kwemisebenzi yazo yokucubungula izinga lokushisa eliphezulu.

6. Isiphetho

Ukukhetha into efanele egoqayo ukuze-incibilike izinga lokushisa eliphezulu kuyisinqumo esibalulekile, esinamasu amakhulu esithinta ngokuqondile ikhwalithi yomkhiqizo, ukuphepha kokusebenza, ukusebenza kahle kwamandla, kanye nezomnotho jikelele zokukhiqiza. Kusukela kunhlanganisela ye-graphite ne-silicon carbide esetshenziswa ezindaweni ezimatasa-ezingezona i-ferrous kuya{3}}ezihlanzekile ze-alumina kanye nemikhumbi yensimbi engavamile esetshenziswa ocwaningweni oluthuthukisiwe nokukhiqizwa kwe-aerospace, uhlobo ngalunye lwe-crucible luletha ibhalansi ehlukile yezakhiwo ezishisayo, zemishini, nezamakhemikhali etafuleni. Ngokuhlola ngokucophelela izici ezifana nezinga lokushisa eliphezulu lokusebenza, ukumelana nokushaqeka kwe-thermal, ukusebenzisana kwamakhemikhali neshaja encibilikisiwe, nokusebenzisa izimiso eziqinile zangaphambi{5}}zokushisa nezokulungisa, onjiniyela bangaqinisekisa ukuthinta okuthembekile, nokuphephile. Njengoba i-industrial metallurgy kanye nesayensi yezinto ezibonakalayo iqhubeka nokuthuthuka ngokushesha, ukuqonda ukusebenzisana okuyinkimbinkimbi phakathi kwekhemistri encibilikayo nokusebenza kwe-crucible kuzohlala kuyikhono eliyisisekelo lokucubungula okuphumelelayo{7}}kwezinga lokushisa eliphezulu.