Ukusabela okungalunganga
Ukusabela okubangela ukudumbai-silicon carbide ceramicInkqubo yemveliso ibandakanya ukuhlanganiswa kweseramikhi, ukuhlanganiswa kwearhente yokungena kwe-sintering flux, ukulungiswa kwemveliso yeseramikhi yokusabela, ukulungiswa kweseramikhi yomthi wesilicon carbide kunye namanye amanyathelo.
I-nozzle ye-silicon carbide ekhupha i-reaction sintering
Okokuqala, i-80-90% yomgubo weseramikhi (owenziwe ngumgubo omnye okanye emibini yeumgubo we-silicon carbidekunye ne-boron carbide powder), i-3-15% yomgubo wekhabhoni (owenziwe nge-carbon black enye okanye ezimbini kunye ne-phenolic resin) kunye ne-5-15% ye-molding agent (i-phenolic resin, i-polyethylene glycol, i-hydroxymethyl cellulose okanye i-paraffin) zixutywa ngokulinganayo kusetyenziswa i-ball mill ukufumana umgubo oxutyiweyo, owomiswa nge-spray uze ucolwe, uze ucinezelwe kwi-mold ukuze ufumane i-ceramic compact enemilo eyahlukeneyo.
Okwesibini, i-60-80% ye-silicon powder, i-3-10% ye-silicon carbide powder kunye ne-37-10% ye-boron nitride powder zixutywa ngokulinganayo, kwaye zicinezelwe kwi-mold ukuze zenze i-sintering flux infiltration agent compact.
Emva koko i-ceramic compact kunye ne-sintered infiltrant compact ziyahlanganiswa, kwaye ubushushu bunyuswa bube yi-1450-1750℃ kwisithando somoya esine-vacuum degree engaphantsi kwe-5×10-1 Pa ukuze kufakwe i-sintering kunye nokugcinwa kobushushu kangangeeyure ezi-1-3 ukuze kufunyanwe imveliso ye-sintered ceramic. Intsalela engaphakathi kumphezulu we-sintered ceramic isuswa ngokucofa ukuze kufunyanwe iphepha le-ceramic elixineneyo, kwaye imo yokuqala ye-compact igcinwe.
Okokugqibela, inkqubo yokusila i-reaction iyamkelwa, oko kukuthi, i-silicon engamanzi okanye i-silicon alloy enomsebenzi wokusabela kubushushu obuphezulu ingena kwi-porous ceramic blank equlethe ikhabhoni phantsi kwesenzo samandla e-capillary, kwaye iphendula nekhabhoni ekuyo ukuze yenze i-silicon carbide, eya kwanda ngobuninzi, kwaye ii-pores eziseleyo zizaliswa yi-elemental silicon. I-porous ceramic blank inokuba yi-carbon ecocekileyo okanye i-silicon carbide/carbon-based composite material. Eyokuqala ifunyanwa ngokucubungula nge-catalytically kunye ne-pyrolyzing i-organic resin, i-pore former kunye ne-solvent. Eyokugqibela ifunyanwa ngokusila i-silicon carbide particles/resin-based composite materials ukuze kufunyanwe i-silicon carbide/carbon-based composite materials, okanye ngokusebenzisa i-α-SiC kunye ne-carbon powder njengezinto zokuqala kunye nokusebenzisa inkqubo yokucinezela okanye yokujova ukuze kufunyanwe izinto ezihlanganisiweyo.
Ukucoca ngaphandle koxinzelelo
Inkqubo yokusila engenaxinzelelo ye-silicon carbide inokwahlulwahlulwa ibe yi-solid-phase sintering kunye ne-liquid-phase sintering. Kwiminyaka yakutshanje, uphando malungaiiseramikhi zesilicon carbideekhaya nakwamanye amazwe, ikakhulu kugxilwe ekutshiseni izinto ngolwelo. Inkqubo yokulungiselela i-ceramic yile: ukutshiza ibhola ngezinto ezixutyiweyo–>ukutshiza nge-granulation–>ukucinezela okomileyo–>ukuqina komzimba oluhlaza–>ukutshiza nge-vacuum.
Iimveliso ze-silicon carbide ezicinezelweyo ezingenaxinzelelo
Yongeza iinxalenye ezingama-96-99 ze-silicon carbide ultrafine powder (50-500nm), iinxalenye ezi-1-2 ze-boron carbide ultrafine powder (50-500nm), iinxalenye ezingama-0.2-1 ze-nano-titanium boride (30-80nm), iinxalenye ezili-10-20 ze-phenolic resin enyibilikayo emanzini, kunye neenxalenye ezingama-0.1-0.5 ze-high-efficiency dispersant kwi-ball mill ukuze kugaywe ibhola kwaye kuxutywe iiyure ezingama-24, uze ufake i-mixed slurry kwi-mixing barrel ukuze uxube iiyure ezi-2 ukuze ususe amaqamza kwi-slurry.
Lo mxube ungentla utshizwa kwinqaba yegranulation, kwaye umgubo wegranulation onesimo esihle see-particle, ukugeleza okuhle, uluhlu oluncinci lokusasazwa kwee-particle kunye nokufuma okuphakathi kufunyanwa ngokulawula uxinzelelo lwespray, ubushushu bokungena komoya, ubushushu bokuphuma komoya kunye nobukhulu bee-particle ze-spray sheet. Ukuguqulwa kwe-centrifugal frequency yi-26-32, ubushushu bokungena komoya yi-250-280℃, ubushushu bokuphuma komoya yi-100-120℃, kwaye uxinzelelo lokungena kwe-slurry yi-40-60.
Umgubo wegranulation ongentla ufakwa kwi-mold ye-carbide eqinisiweyo ukuze icinezelwe ukuze kufunyanwe umzimba oluhlaza. Indlela yokucinezela icinezela kwicala ngalinye, kwaye i-tonnage yoxinzelelo lwesixhobo somatshini yi-150-200 yeetoni.
Umzimba oluhlaza ocinezelweyo ufakwa kwi-oven yokomisa ukuze womiswe kwaye ucolwe ukuze ufumane umzimba oluhlaza oqinileyo.
Umzimba oluhlaza ocoliweyo ongentla ubekwe kwindawoisixhobo sokubethela igrafayithikwaye ibekwe kakuhle nangokucocekileyo, emva koko i-graphite crucible enomzimba oluhlaza ifakwa kwisithando sokutshisa esinobushushu obuphezulu ukuze sidubule. Ubushushu bokudubula yi-2200-2250℃, kwaye ixesha lobushushu liyiyure eli-1-2. Ekugqibeleni, kufunyanwa iiseramikhi ze-silicon carbide ezingenaxinzelelo ezisebenza kakuhle.
Ukucoca ngesigaba esiqinileyo
Inkqubo yokusila engenaxinzelelo ye-silicon carbide inokwahlulwahlulwa ibe yi-solid-phase sintering kunye ne-liquid-phase sintering. Ukusila kwe-liquid-phase kufuna ukongezwa kwezongezo zokusila, ezifana nezongezo ze-Y2O3 binary kunye ne-ternary, ukwenza i-SiC kunye nezinto zayo ezidityanisiweyo zibe ne-liquid-phase sintering kwaye zifezekise uxinano kubushushu obuphantsi. Indlela yokulungiselela i-solid-phase sintered silicon carbide ceramics ibandakanya ukuxuba izinto eziluhlaza, i-spray granulation, i-molding, kunye ne-vacuum sintering. Inkqubo yemveliso ethile yile ilandelayo:
I-70-90% ye-submicron α silicon carbide (200-500nm), i-0.1-5% ye-boron carbide, i-4-20% ye-resin, kunye ne-5-20% ye-organic binder zifakwa kwi-mixer kwaye zongezwe ngamanzi acocekileyo ukuze kuxutywe ngamanzi. Emva kweeyure ezi-6-48, i-slurry exutyiweyo idlula kwi-sefu ye-60-120 mesh;
I-slurry ehluziweyo ihluzwa nge-spray granulation tower. Ubushushu bokungena kwe-spray granulation tower yi-180-260℃, kwaye ubushushu bokuphuma buyi-60-120℃; ubuninzi bezinto ezihluziweyo yi-0.85-0.92g/cm3, ukunyibilika yi-8-11s/30g; izinto ezihluziweyo zihluzwa nge-60-120 mesh seal ukuze zisetyenziswe kamva;
Khetha isikhunta ngokwemilo yemveliso oyifunayo, faka izinto ezigobileyo kwindawo yokubumba, kwaye wenze ukubumba koxinzelelo lobushushu begumbi kuxinzelelo lwe-50-200MPa ukuze ufumane umzimba oluhlaza; okanye beka umzimba oluhlaza emva kokubumba koxinzelelo kwisixhobo sokucinezela esisostatic, yenza ukucinezela okusostatic kuxinzelelo lwe-200-300MPa, kwaye ufumane umzimba oluhlaza emva kokucinezela okwesibini;
Faka umzimba oluhlaza olungiselelwe kumanyathelo angentla kwisithando sokutshisa i-vacuum ukuze sitshise, kwaye esifanelekileyo yi-silicon carbide bulletproof ceramic egqityiweyo; kwinkqubo yokutshisa i-vacuum engentla, qala ukhuphe isithando sokutshisa, kwaye xa iqondo le-vacuum lifikelela kwi-3-5 × 10-2 Emva kwe-Pa, igesi engasebenziyo idluliselwa kwisithando sokutshisa ukuya kuxinzelelo oluqhelekileyo ize emva koko ifudunyezwe. Ubudlelwane phakathi kobushushu bokufudumeza kunye nexesha bubu: ubushushu begumbi ukuya kwi-800℃, iiyure ezi-5-8, ukugcinwa kobushushu kangangeyure eyi-0.5-1, ukusuka kwi-800℃ ukuya kwi-2000-2300℃, iiyure ezi-6-9, ukugcinwa kobushushu kangangeyure e-1 ukuya kwezi-2, uze emva koko upholiswe ngesithando sokutshisa uze uthotywe ukuya kubushushu begumbi.
Isakhiwo esincinci kunye nomda weenkozo ze-silicon carbide ezitshiswe ngoxinzelelo oluqhelekileyo
Ngamafutshane, iiseramikhi ezenziwe ngenkqubo yokusinkcenkceshela ngoxinzelelo zisebenza ngcono, kodwa iindleko zemveliso nazo zinyuswe kakhulu; iiseramikhi ezilungiselelwe ngenkqubo yokusinkcenkceshela ngaphandle koxinzelelo zineemfuno eziphezulu zezinto eziluhlaza, ubushushu obuphezulu bokusinkcenkceshela, utshintsho olukhulu lobungakanani bemveliso, inkqubo enzima kunye nokusebenza okuphantsi; iimveliso zeseramikhi eziveliswe yinkqubo yokusinkcenkceshela ngokusabela zinoxinano olukhulu, ukusebenza okuhle kokulwa nebhola, kunye neendleko zokulungiselela eziphantsi. Iinkqubo ezahlukeneyo zokulungiselela ukusinkcenkceshela zeseramikhi ze-silicon carbide zineengenelo kunye neengxaki zazo, kwaye iimeko zokusetyenziswa nazo ziya kwahluka. Ngumgaqo-nkqubo olungileyo ukukhetha indlela yokulungiselela efanelekileyo ngokwemveliso kunye nokufumana ibhalansi phakathi kweendleko eziphantsi kunye nokusebenza okuphezulu.
Ixesha leposi: Okthobha-29-2024