Safire chinhu chakaoma, chinopfekwa uye chakasimba chine tembiricha yekunyungudika, ine makemikari inert yakawanda, uye inoratidza inonakidza optical properties. Naizvozvo, safire inoshandiswa kune akawanda tekinoroji mashandisirwo uko makuru eindasitiri minda ari optics uye zvemagetsi. Nhasi chikamu chikuru chesafiro yeindasitiri chinoshandiswa senge substrate ye LED uye semiconductor kugadzirwa, inoteverwa nekushandiswa semahwindo ewachi, nhare mbozha kana bar kodhi scanner, kudoma mienzaniso mishoma [1]. Nhasi, nzira dzakasiyana-siyana dzekukura safiri imwe makristasi dziripo, mhedziso yakanaka inogona kuwanikwa semuenzaniso mu [1, 2]. Nekudaro, nzira nhatu dzekukura dzeKyropoulos process (KY), kupisa-exchange nzira (HEM) uye yakaganhurwa-inotsanangurwa firimu-inodyiswa kukura (EFG) inodarika 90% yepasi rose kugadzirwa kwesafiro.

Kuedza kwekutanga kwekristaro yakagadzirwa yakagadzirwa 1877 kune diki ruby ​​​​single crystals [2]. Zviri nyore muna 1926 maitiro eKyropoulos akagadzirwa. Inoshanda muvacuum uye inobvumira kuburitsa hombe cylindrical shape boules emhando yepamusoro. Imwe nzira inonakidza yekukura kwesafire ndeyekumucheto-inotsanangurwa firimu-yakadyiswa kukura. Iyo EFG tekinoroji yakavakirwa pane capillary chiteshi iyo yakazadzwa nemvura-yakanyunguduka uye inobvumira kukura akaumbwa makristasi esafire akadai setsvimbo, machubhu kana mashizha (anonziwo ribhoni). Kusiyana nemitoo iyi nzira yekutsinhana-kupisa, yakazvarwa mukupera kwema1960, inobvumira kukura mabhuru makuru esafire mukati me spun crucible muchimiro che crucible nekutsanangurwa kupisa kubviswa kubva pasi. Nekuti iyo safire boule inonamira kune crucible pakupera kwekukura kwekukura, boules inogona kutsemuka panguva inotonhorera pasi uye iyo crucible inogona kushandiswa kamwe chete.
Chero yeiyi safire crystal yekukura tekinoroji yakafanana iyo yakakosha zvikamu - kunyanya crucibles - inoda yakakwirira-tembiricha refractory simbi. Zvichienderana nekukura kwenzira macrucibles anogadzirwa ne molybdenum kana tungsten, asi simbi dzinoshandiswawo zvakanyanya kupikisa heaters, die-packs uye hot-zone shieldings [1]. Nekudaro, mubepa rino tinotarisisa nhaurirano yedu paKY uye EFG ine hukama misoro sezvo yakatsikirirwa-sintered crucibles inoshandiswa mukuita izvi.
Mumushumo uyu tinopa zvidzidzo zvehunhu hwezvinhu uye kuferefeta pamusoro pemamiriro ekunze ezvakatsikirirwa-sintered zvinhu zvakaita se molybdenum (Mo), tungsten (W) nema alloys ayo (MoW). Muchikamu chekutanga tarisiro yedu iri pane yakakwirira-tembiricha yemechani data uye ductile kune brittle shanduko tembiricha. Kuwedzera kune mechanical properties isu takadzidza thermo-physical properties, kureva coefficient yekuwedzera kwekushisa uye kupisa kwemhepo. Muchikamu chechipiri tinopa zvidzidzo pamusoro pemaitiro ekugadziriswa kwepamusoro kunyanya kuvandudza kuramba kwemacrucibles akazadzwa nealuminium melt. Muchikamu chechitatu tinoshuma pamusoro pezviyero zvekunyorova makona emvura alumina pane refractory simbi pa2100 °C. Takaita zviyedzo zvekunyungudusa paMo, W uye MoW25 alloy (75 wt.% molybdenum, 25 wt.% tungsten) uye takadzidza zvinoenderana nemamiriro akasiyana emuchadenga. Nekuda kubva mukuferefeta kwedu tinopa MoW sechinhu chinonakidza mukukura kwesafire tekinoroji uye seimwe ingangoita imwe nzira kune pure molybdenum uye tungsten.
High-temperature mechanical uye thermo-physical properties
Iyo sapphire crystal yekukura nzira dzeKY neEFG dzinoshanda zviri nyore kune inodarika 85% yepasirese sapphire uwandu share. Munzira dzese dziri mbiri, iyo alumina yemvura inoiswa muakatsikirirwa-sintered crucibles, anowanzo gadzirwa tungsten yeKY maitiro uye akagadzirwa ne molybdenum yeEFG maitiro. Crucibles akakosha sisitimu zvikamu zveaya maitiro ekukura. Tichivavarira pfungwa yekukwanisa kuderedza mitengo ye tungsten crucibles muKY maitiro pamwe nekuwedzera hupenyu hwema molybdenum crucibles muEFG maitiro, takagadzira uye kuedza kuwedzera maMoW alloys maviri, kureva MoW30 ine 70 wt.% Mo uye 30 wt. % W uye MoW50 ine 50 wt.% Mo uye W imwe neimwe.
Pazvidzidzo zvese zvehunhu hwezvinhu takagadzira dzakadzvanywa-sintered ingots dzeMo, MoW30, MoW50 uye W. Tafura I inoratidza densities uye avhareji saizi dzezviyo zvinoenderana nekutanga zvinyorwa.

Tafura I: Pfupiso yezvakatsikirirwa-sintered zvinhu zvinoshandiswa kuyera pane mechaniki uye thermo-muviri zvimiro. Tafura inoratidza kuwanda uye avhareji saizi yezviyo zvekutanga nyika dzezvinhu

Nekuti macrucibles ane nguva refu akaoneswa tembiricha yakakwira, takaita bvunzo dzakadzama kunyanya mukupisa kwepamusoro pakati pe1000 ° C uye 2100 ° C. Mufananidzo 1 unopfupisa mhedzisiro iyi yeMo, MoW30, uye MoW50 apo iyo 0.2 % goho simba (Rp0.2) uye elongation yekutyoka (A) inoratidzwa. Kuenzanisa, nzvimbo yedata yekudzvanywa-sintered W inoratidzwa pa2100 ° C.
Kune yakanakira solid-soluted tungsten mu molybdenum iyo Rp0.2 inotarisirwa kuwedzera kana ichienzaniswa neyakachena Mo zvinhu. Kune tembiricha inosvika 1800 °C ese maMoW alloys anoratidza kanenge ka2 kakakwira Rp0.2 pane yeMo, ona Mufananidzo 1(a). Kune tembiricha yepamusoro chete MoW50 inoratidza yakagadziridzwa zvakanyanya Rp0.2. Yakadzvanywa-sintered W inoratidza yepamusoro Rp0.2 pa2100 °C. Iwo bvunzo dzekusimba dzinoratidza zvakare A sezvakaratidzwa mumufananidzo 1(b). Ose ari maviri alloys eMoW anoratidza kurebesa kwakada kufanana kutsika dzekutyoka izvo zvinowanzova hafu yeukoshi hweMo. Iyo yakanyanya kukwirisa A yetungsten pa2100 °C inofanirwa kukonzereswa nechimiro chayo chakatsetseka kana chichienzaniswa neMo.
Kuti uone iyo ductile to brittle transition tembiricha (DBTT) yeakatsikirirwa-sintered molybdenum tungsten alloys, zvakare zviyero pamakona ekukotama akaitwa pane akasiyana tembiricha. Migumisiro inoratidzwa mumufananidzo 2. DBTT inowedzera nekuwedzera tungsten content. Nepo iyo DBTT yeMo iri yakadzikira ingangoita 250 °C, alloys MoW30 neMoW50 anoratidza DBTT inosvika 450 °C uye 550 °C, zvichiteerana.

Inopindirana neiyo mechanical characterization takadzidzawo thermo-physical properties. The coefficient of thermal expansion (CTE) yakayerwa mupush-rod dilatometer [3] munzvimbo yekushisa kusvika ku1600 °C uchishandisa sampuli ine Ø5 mm uye 25 mm kureba. Zviyero zveCTE zvinoratidzwa muMufananidzo 3. Zvinhu zvose zvinoratidza kutsamira kwakafanana kweCTE nekuwedzera kwekushisa. Iko CTE tsika dze alloys MoW30 neMoW50 dziri pakati pezvinokosha zveMo neW. Nokuti iyo yakasara porosity yezvinhu zvakatsikirirwa-sintered hazvizivikanwi uye ine maduku maduku ega, CTE yakawanikwa yakafanana nepamusoro-density zvinhu zvakadai semashizha uye tsvimbo [4].
Kupisa kwekushisa kwezvinhu zvakatsikirirwa-sintered zvakawanikwa nekuyera zvose zvinopisa kupisa uye kupisa kwakananga kwemuenzaniso neØ12.7 mm uye 3.5 mm ukuru uchishandisa laser flash method [5, 6]. Kune isotropic zvinhu, senge zvakatsikirirwa-sintered zvinhu, chaiyo kupisa kunogona kuyerwa nenzira imwecheteyo. Zviyero zvakatorwa mutembiricha iri pakati pe25 °C ne1000 °C. Kuverenga iyo yekupisa conductivity yatakashandisa mukuwedzera iyo densities yezvinhu sezvakaratidzwa muTable I uye kufungidzira tembiricha yakazvimirira densities. Mufananidzo 4 unoratidza mhedzisiro yekupisa kwekushisa kwekudzvanywa-sintered Mo, MoW30, MoW50 uye W. Thermal conductivity

yeMoW alloys yakaderera pane 100 W/mK kune ese tembiricha akaongororwa uye idiki zvakanyanya kana zvichienzaniswa ne pure molybdenum uye tungsten. Pamusoro pezvo, maconductivity eMo neW anodzikira nekuwedzera tembiricha ukuwo conductivity yeMoW alloy inoratidza kuwedzera kukosha nekuwedzera tembiricha.
Chikonzero chemusiyano uyu hachina kuferefetwa mubasa iri uye chichava chikamu cheongororo yeramangwana. Zvinozivikanwa kuti kune simbi chikamu chinotonga chekupisa kwekupisa pakudziya kwakaderera ndiko mupiro wephonon nepo pakupisa kwakanyanya iyo electron gasi inotonga kudziya kwemhepo [7]. Mafonifoni anokonzerwa nekusakwana kwezvinhu uye kukanganisa. Zvisinei, kuwedzera kwekupisa kwekushisa mumhando yekushisa kwepasi kunocherechedzwa kwete chete kweMoW alloys asiwo kune zvimwe zvakasimba-solution zvinhu zvakadai se tungsten-rhenium [8], apo mupiro we electron inoita basa rinokosha.
Kuenzanisa kwema mechanical uye thermo-physical properties kunoratidza kuti MoW chinhu chinonakidza chekushanda kwesafire. Pakupisa kwepamusoro> 2000 °C simba regoho rakakwirira kudarika remolybdenum uye hupenyu hurefu hwemacrucibles hunofanirwa kuitika. Nekudaro, izvo zvinhu zvinova zvakanyanya brittle uye machining uye kubata kunofanirwa kugadziridzwa. Iyo yakanyanya kuderedzwa kupisa conductivity yeakadzvanywa-sintered MoW sezvakaratidzwa muFigure 4 inoratidza kuti yakagadziridzwa kupisa-kumusoro uye inotonhorera-pasi paramita yevira iri kukura ingave yakakosha. Kunyanya muchikamu chekupisa, uko alumina inoda kunyungudutswa mucrucible, kupisa kunotakurwa chete necrucible kune yayo mbishi yekuzadza zvinhu. Iyo yakaderedzwa yekupisa conductivity yeMoW inofanirwa kutariswa kudzivirira yakakwira yekupisa kusagadzikana mucrucible. Iyo yakawanda yeCTE tsika dzeMoW alloys inonakidza mumamiriro eiyo HEM crystal yekukura nzira. Sezvakakurukurwa mureferensi [9] iyo CTE yeMo iri kukonzera kusungirirwa kwesafiri muchikamu chinotonhorera. Naizvozvo, iyo yakaderedzwa CTE yeMoW alloy inogona kunge iri kiyi yekuona zvakare inogona kushandiswa spun crucibles yeHEM maitiro.
Surface conditioning yepressed-sintered refractory metals
Sezvakakurukurwa munhanganyaya, akatsikirirwa-sintered crucibles anowanzo shandiswa musafire crystal yekukura maitiro ekupisa uye kuchengetedza alumina inyauka zvishoma pamusoro pe2050 °C. Chimwe chakakosha chinodiwa chekupedzisira chesafire crystal quality ndechekuchengeta tsvina uye gasi mabhubhu mukunyunguduka zvakaderera sezvinobvira. Zvikamu zvakadzvanywa-sintered zvine porosity yakasara uye inoratidza chimiro chakanyatsogadzirwa. Ichi chimiro chakatsetseka chine porosity yakavharika haina kusimba pakuwedzera kukora kwesimbi kunyanya neoxidic melts. Rimwe dambudziko remakristasi esafire madiki gasi mabhuru mukati mekunyungudika. Kuumbwa kwegasi bubbles kunowedzerwa nekuwedzera kwepamusoro roughness ye refractory chikamu chiri kusangana nekunyunguduka.

Kuti tikunde idzi nyaya dzeakatsikirirwa-sintered zvinhu isu tinoshandisa mechanical surface kurapwa. Takaedza nzira yacho nechishandiso chekutsikirira uko mudziyo weceramic uri kushanda pasi pasi pekumanikidzwa kwakatsanangurwa kwechikamu chakadzvanywa-sintered [10]. Iyo inoshanda yekumanikidza kudzvanya pamusoro pepamusoro inopesana zvichienderana nekusangana kwechiso checeramic chishandiso panguva ino yekumisikidza. Nekurapwa uku kudzvanyirira kwakanyanya kunogona kuiswa munharaunda kune yakatsikirirwa-sintered zvinhu uye iyo yepasi pevhu yakakanganiswa. Mufananidzo 5 unoratidza muenzaniso weyakadzvanywa-sintered molybdenum specimen iyo yakashandiswa neiyi nzira.
Mufananidzo 6 unoratidza zvine hutsika kutsamira kweiyo inoshanda yekudzvanya kudzvanya pane iyo mudziyo kumanikidza. Iyo data yakatorwa kubva kune zviyero zveiyo static imprints yechishandiso mukudzvanywa-sintered molybdenum. Mutsara unomiririra kukodzera kune data maererano nemuenzaniso wedu.

Mufananidzo 7 unoratidza mibairo yekuongorora yakapfupikiswa yekuomarara kwepamusoro uye kuyerwa kwehukukutu hwepasi sebasa rekumanikidza kwechishandiso chezvinhu zvakasiyana-siyana zvakadzvanywa-sintered zvakagadzirirwa sedhisiki. Sezvakaratidzwa muMufananidzo 7 (a) kurapwa kunoguma nekuoma kwepamusoro. Kuoma kwezvinhu zvose zvakaedzwa Mo neMoW30 kunowedzerwa ne150%. Pakumanikidza kwechishandiso chepamusoro kuomarara hakusi kuwedzera kuwedzera. Mufananidzo 7(b) unoratidza kuti nzvimbo dzakatsetseka kwazvo dzine Ra dzakadzika se 0.1 μm yeMo inogoneka. Pakuwedzera maturusi anomanikidza kushata kweMo kunowedzera zvakare. Nekuti MoW30 (uye W) zvinhu zvakaoma kupfuura Mo, iyo inowanikwa Ra values ​​yeMoW30 uye W inowanzokwira 2-3 times kupfuura yeMo. Mukupesana neMo, kushata kwepamusoro kweW kunodzikira nekushandisa maturusi epamusoro ezvishandiso mukati me yakaedzwa parameter range.
Yedu yekuongorora electron microscopy (SEM) zvidzidzo zvenzvimbo dzakagadziriswa zvinosimbisa data rekuoma kwepamusoro, ona Mufananidzo 7(b). Sezvinoratidzwa muMufananidzo 8 (a), kunyanya kudzvanywa kwezvishandiso kwakakwira kunogona kutungamira mukukuvadzwa kwepasi pezviyo uye microcracks. Mamiriro ekunyanya kushushikana kwepamusoro kunogona kukonzera kunyange kubviswa kwezviyo kubva pamusoro, ona Mufananidzo 8(b). Mamiriro akafanana anogonawo kucherechedzwa kune MoW uye W pane mamwe machining paramita.
Kuti tidzidze maitiro eiyo nzira yekumisikidza pamusoro pechimiro chezviyo uye maitiro ekushisa kwayo, takagadzira annealing samples kubva kumatatu ebvunzo disks eMo, MoW30 uye W.

Iwo masampuli akabatwa kwemaawa maviri patembiricha dzakasiyana dzekuyedza mukati me800 ° C kusvika 2000 ° C uye madiki akagadzirirwa kuongororwa microscope.
Mufananidzo 9 unoratidza microsection mienzaniso yeakadzvanywa-sintered molybdenum. Mamiriro ekutanga enzvimbo yakarapwa anoratidzwa muMufananidzo 9 (a). Nzvimbo yacho inoratidza chinenge chakakora mukati mehupamhi hunosvika mazana maviri μm. Pazasi peiyi dhizaini chimiro chakajairwa chemidziyo ine sintering pores inoonekwa, iyo yakasara porosity inenge 5%. Iyo yakayerwa yasara porosity mukati meiyo yepamusoro layer iri pasi pe1%. Mufananidzo 9(b) unoratidza chimiro chezviyo mushure mekuvhara kwe2 h pa1700 °C. Kukora kwedense surface layer kwawedzera uye zviyo zvakakura zvakanyanya kupfuura zviyo zviri muvhoriyamu isina kuchinjwa nemamiriro ekunze. Iyi yakashata-grained yakanyanya dense layer ichave inoshanda kuvandudza inokambaira kuramba yezvinhu.
Isu takadzidza kutsamira kwetembiricha yepasi repamusoro maererano nekukora uye saizi yezviyo kune akasiyana maturusi kumanikidza. Mufananidzo 10 unoratidza mienzaniso inomiririra yehukuru hwepamusoro hweMo neMoW30. Sezvinoratidzwa muFigure 10(a) iyo yekutanga dhizaini ukobvu kunoenderana nemachining chishandiso kuseta. Pane tembiricha inodzika inopfuura 800 ° C iyo yekumusoro layer yeMo inotanga kuwedzera. Pa 2000 °C ukobvu hwe layer hunosvika 0.3 kusvika 0.7 mm. KuMoW30 kuwedzera kwehutema hwepamusoro hunogona kungoonekwa chete kune tembiricha dziri pamusoro pe1500 °C sezvakaratidzwa Mufananidzo 10(b). Zvakadaro pa2000 °C ukobvu hweMoW30 hwakanyanya kufanana neMo.

Sekuongorora ukobvu hwenzvimbo yepasi, Mufananidzo 11 unoratidza avhareji yesaizi yedata yeMo neMoW30 yakayerwa muchikamu chepamusoro sebasa rekupisa tembiricha. Sezvinogona kutaurwa kubva kunhamba, saizi yezviyo iri - mukati meyero kusavimbika - yakazvimirira pane yakaiswa parameter setup. Kukura kwezviyo kunoratidza kukura kwezviyo zvisina kujairika kwepamusoro-soro kunokonzerwa nekushanduka kwenzvimbo. Mbeu dzeMolybdenum dzinokura patembiricha yekuyedzwa inopfuura 1100 ° C uye saizi yezviyo ingangoita 3 yakakura pa2000 ° C zvichienzaniswa nekukura kwezviyo zvekutanga. Mhodzi dzeMoW30 dzepamusoro-soro dzakamisikidzwa dzinotanga kukura pamusoro petembiricha ye1500 °C. Pakuyedza tembiricha ye2000 °C avhareji saizi yezviyo ingangoita 2 nguva yekutanga saizi yezviyo.
Muchidimbu, kuferefeta kwedu pamusoro pemaitiro ekugadzirisa epamusoro kunoratidza kuti inoshanda kune yakatsikiswa-sintered molybdenum tungsten alloys. Uchishandisa nzira iyi, nzvimbo dzine kuomarara kwakawedzera pamwe nenzvimbo dzakatsetseka dzine Ra zvakanaka pazasi 0.5 μm dzinogona kuwanikwa. Iyo yekupedzisira pfuma inonyanya kubatsira kudzikisa gasi bubble. Iyo yakasara porosity iri pamusoro pedenga iri pedyo ne zero. Annealing uye microsection zvidzidzo zvinoratidza kuti yakanyanya kusimba pamusoro pedhiri neyakajairwa ukobvu hwe500 μm inogona kuwanikwa. Apa iyo machining parameter inogona kudzora ukobvu hwesero. Kana uchifumura zvinhu zvakamisikidzwa kune tembiricha yepamusoro sezvinowanzo shandiswa mukukura kwesafire, iyo yepamusoro-soro inova yakakasharara-yakaomeswa nehukuru hwezviyo 2-3 zvakapetwa kaviri pane pasina machining epamusoro. Saizi yezviyo muchikamu chepamusoro chakazvimirira pane machining parameters. Nhamba yemiganhu yezviyo pamusoro pepamusoro inobudirira kuderedzwa. Izvi zvinotungamira kupikisa kwepamusoro kurwisa kupararira kwezvinhu pamwe nemiganhu yezviyo uye kunyunguduka kwakaderera. Pamusoro pezvo, iyo tembiricha yepamusoro inokambaira kuramba yekutsikiswa-sintered molybdenum tungsten alloys inovandudzwa.

Kunyorova zvidzidzo zvealumina alumina pane refractory simbi
Kunyorova kwealumina yemvura pa molybdenum kana tungsten kunonyanya kufarira muindasitiri yesafire. Kunyanya yeEFG maitiro iyo alumina yekunyorova maitiro mu die-pack capillaries inotarisisa mwero wekukura kwetsvimbo yesafire kana maribhoni. Kuti tinzwisise kukanganisa kwezvinhu zvakasarudzwa, kushata kwepamusoro kana mamiriro ekunze takaitisa zviyero zvemakona ekunyorova [11].
Payeyero yekunyorova bvunzo ma substrates ane saizi ye1 x 5 x 40 mm³ akagadzirwa kubva kuMo, MoW25 uye W sheet zvinhu. Nekutumira yakakwira magetsi ikozvino kuburikidza nesimbi sheet substrate tembiricha yekunyunguduka yealumina ye2050 ° C inogona kuwanikwa mukati mehafu yeminiti. Kune zviyero zvemakona madiki ealuminium particles akaiswa pamusoro pepepa samples uye zvichizotevera

yakanyunguduka kuita madonhwe. An automated imaging system yakanyora kunyunguduka kwakanyunguduka sezvinoratidzwa semuenzaniso muMufananidzo 12. Chimwe nechimwe chekuedza kunyunguduka chinobvumira kuyera kona yekunyorova nekuongorora kudonhedza contour, ona Mufananidzo 12 (a), uye substrate baseline kazhinji nguva pfupi mushure mekudzima. kupisa ikozvino, ona Mufananidzo 12(b).
Takaita zviyero zvemakona ekunyorova kune maviri akasiyana mamiriro ekunze, vacuum pa10-5mbar uye argon pa900 mbar pressure. Pamusoro pezvo, mhando mbiri dzepamusoro dzakaedzwa, kureva nzvimbo dzakashata neRa ~ 1 μm uye nzvimbo dzakatsetseka dzine Ra ~ 0.1 μm.
Tafura II inopfupikisa mhedzisiro yezviyero zvese pamakona ekunyorova eMo, MoW25 uye W yenzvimbo dzakatsetseka. Kazhinji, iyo yekunyorova angle yeMo idiki padiki kana ichienzaniswa nezvimwe zvinhu. Izvi zvinoreva kuti alumina inonyungudika iri kunyorova Mo zvakanyanya izvo zvinobatsira muEFG yekukura maitiro. Makona ekunyorova anowanikwa kune argon akadzikira zvakanyanya pane makona evacuum. Kune rough substrate surfaces tinowana zvakarongeka zvakati pazasi wetting angles. Aya makoshero anowanzo kuita 2° kuderera pane makona akapihwa muTebhurari II. Nekudaro, nekuda kwechiyero chekusavimbika, hapana mutsauko wakakura wekona pakati penzvimbo dzakatsetseka uye dzakakasharara dzinogona kutaurwa.

Takayera makona ekunyorova zvakare kune mamwe mamhepo emhepo, kureva kukosha pakati pe10-5 mbar ne900 mbar. Kuongorora kwekutanga kunoratidza kuti kune zvinomanikidza pakati pe10-5 mbar uye 1 mbar ngirozi yekunyorova haichinji. Chete pamusoro pe 1 mbar kona yekunyorova inova yakaderera pane yakaonekwa pa900 mbar argon (Tafura II). Kunze kwemamiriro emuchadenga, chimwe chinhu chakakosha pamaitiro ekunyorova kwealumina inonyunguduka ndeye mweya weokisijeni. Miedzo yedu inoratidza kuti kupindirana kwemakemikari pakati pekunyunguduka uye simbi substrates kunoitika mukati meyero yakakwana yenguva (kazhinji 1 miniti). Isu tinofungidzira kunyungudika kwemamorekuru eAl2O3 mune zvimwe zvinhu zveokisijeni zvinopindirana neiyo substrate zvinhu padhuze nedonhwe rekunyungudika. Zvimwe zvidzidzo pari zvino zvirikuenderera mberi kuongorora zvakadzama zvese kutsamira kwekumanikidzwa kwekona yekunyorova uye kupindirana kwemakemikari ekunyungudika nesimbi dzinoramba.