Reaction sintering
Ukusabela sinteringi-silicon carbide ceramicinkqubo yokuvelisa ibandakanya ukudibanisa ceramic, sintering flux infiltration arhente ukuhlanganisela, reaction sintering sintering ukulungiselelwa imveliso eludongeni, isilicon carbide iinkuni ukulungiswa ceramic kunye namanye amanyathelo.
I-rection sintering silicon carbide nozzle
Okokuqala, i-80-90% ye-ceramic powder (ehlanganiswe enye okanye ezimbini zomguboi-silicon carbide powderkunye ne-boron carbide powder), i-3-15% ye-carbon source powder (eyenziwe enye okanye ezimbini ze-carbon black kunye ne-phenolic resin) kunye ne-5-15% ye-ejenti yokubumba (i-phenolic resin, i-polyethylene glycol, i-hydroxymethyl cellulose okanye iparafini) ixutywe ngokulinganayo. usebenzisa ilitye lokusila ukufumana umgubo oxubeneyo, otshizwayo womiswe kwaye uhlanjululwe, kwaye emva koko ucinezelwe kumbumba ukuze ufumane i-ceramic compact eneempawu ezahlukeneyo. iimilo.
Okwesibini, i-60-80% ye-silicon powder, i-3-10% ye-silicon carbide powder kunye ne-37-10% ye-boron nitride powder ixutywe ngokulinganayo, kwaye icinezelwe kwi-mold ukufumana i-agent ye-sintering flux infiltration compact.
I-ceramic compact kunye ne-sintered infiltrant compact ihlanganiswe kunye, kwaye ubushushu buphakanyiswe ukuya kwi-1450-1750 ℃ kwisithando somlilo esinedigri yevacuum engekho ngaphantsi kwe-5 × 10-1 Pa yokutshisa kunye nokugcinwa kobushushu kwi-1-3. iiyure ukufumana impendulo sintered imveliso ceramic. I-infiltrant i-infiltration ebusweni be-ceramic sintered isuswa ngokucofa ukuze ufumane ishidi le-ceramic eshinyeneyo, kwaye i-shape yokuqala ye-compact igcinwa.
Ekugqibeleni, inkqubo yokusabela ye-sintering yamkelwa, oko kukuthi, i-silicon yolwelo okanye i-silicon alloy kunye nomsebenzi wokuphendula kwiqondo lokushisa eliphezulu ingena kwi-porous ceramic blank equlethe i-carbon phantsi kwesenzo se-capillary force, kwaye isabela kunye nekhabhoni kuyo ukuze yenze i-silicon carbide, ethi. iya kwanda ngomthamo, kwaye iipores eziseleyo zizaliswe ngesilicon esisiseko. I-ceramic engenanto engenanto ingaba yikhabhoni ecocekileyo okanye i-silicon carbide / i-carbon-based composite material. Eyangaphambili ifunyenwe ngokunyanga kunye ne-pyrolyzing i-organic resin, i-pore yangaphambili kunye ne-solvent. Le yokugqibela ifunyenwe ngepyrolyzing isilicon carbide particles/resin-based composite materials ukufumana isilicon carbide/carbon-based composite materials, okanye ngokusebenzisa i-α-SiC kunye necarbon powder njengezinto zokuqala kunye nokusebenzisa inkqubo yokucinezela okanye yokutofa ukufumana i-composite. impahla.
Sintering ngaphandle koxinzelelo
Inkqubo ye-silicone carbide enganyanzelisiyo inokwahlulwa ibe yi-slid-phase sintering kunye ne-liquid-phase sintering. Kwiminyaka yakutshanje, uphando kwii-silicon carbide ceramicsekhaya nakumazwe aphesheya igxile ikakhulu kwi-liquid-phase sintering. Inkqubo yokulungiswa kwe-ceramic yile: i-milling material ball milling–>spray granulation–>dry pressing–>green body solidification–>vacuum sintering.
Iimveliso ze-silicon carbide ezingenaxinzelelo
Yongeza iinxalenye ezingama-96-99 zesilicon carbide ultrafine powder (50-500nm), 1-2 iinxalenye ze-boron carbide ultrafine powder (50-500nm), 0.2-1 iinxalenye ze-nano-titanium boride (30-80nm), 10-20 iinxalenye i-resin ye-phenolic enyibilikayo yamanzi, kunye ne-0.1-0.5 iinxalenye ze-high-efficiency dispersant kwibhola lokusila ibhola lokugaya kunye nokuxuba iiyure ezingama-24, kwaye ubeke i-slurry edibeneyo kwi-barrel yokuxuba ukuze uqhube iiyure ze-2 ukususa amaqamza kwi-slurry.
Lo mxube ungentla utshizwe kwinqaba yegranulation, kunye nomgubo wegranulation kunye ne-particle morphology enhle, i-fluidity enhle, uluhlu oluncinci lokusabalalisa amasuntswana kunye nokufuma okuphakathi kufumaneka ngokulawula uxinzelelo lokutshiza, ubushushu bokungena emoyeni, ubushushu bokukhutshwa komoya kunye nobungakanani beshiti lokutshiza. I-centrifugal frequency conversion yi-26-32, i-air inlet iqondo lokushisa yi-250-280 ℃, iqondo lokushisa lomoya liyi-100-120 ℃, kunye noxinzelelo lwe-slurry inlet yi-40-60.
I powder granulation ingentla ifakwe kwi-cemented carbide mold ukuze ucinezele ukufumana umzimba oluhlaza. Indlela yokucinezela ingcinezelo ye-bidirectional, kwaye i-tonnage yoxinzelelo lwesixhobo somatshini yi-150-200 tons.
Umzimba ohlaza ocinezelweyo ufakwa kwi-oven yokomisa ukuze yomiswe kwaye unyange ukufumana umzimba oluhlaza onamandla aluhlaza.
Lo mzimba uluhlaza uphilisiweyo ubekwe kwindawo ai-graphite cruciblekwaye icwangciswe ngokusondeleyo kwaye ngokucocekileyo, kwaye ke i-graphite crucible kunye nomzimba oluhlaza ifakwe kwi-high-temperature vacuum sintering eziko lokudubula. Ubushushu bokudubula yi-2200-2250 ℃, kwaye ixesha lokugquma liyi-1-2 iiyure. Ekugqibeleni, iiceramics ze-silicon carbide ezisebenza ngokuphezulu ezingenaxinzelelo zifunyenwe.
I-Solid-phase sintering
Inkqubo ye-silicone carbide enganyanzelisiyo inokwahlulwa ibe yi-slid-phase sintering kunye ne-liquid-phase sintering. I-Liquid-phase sintering ifuna ukongezwa kwe-sintering additives, njenge-Y2O3 yokubini kunye ne-ternary additives, ukwenza i-SiC kunye nezixhobo zayo ezidibeneyo zibonise i-liquid-phase sintering kwaye zifezekise ukuxinana kwiqondo lokushisa eliphantsi. Indlela yokulungiselela i-slid-phase sintered sintered silicone carbide ceramics ibandakanya ukuxubana kwemathiriyeli ekrwada, igranulation yokutshiza, ukubumba, 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 ifakwe kwi-mixer kwaye yongezwa ngamanzi ahlambulukileyo okumanzi. ukuxuba. Emva kweeyure ezingama-6-48, i-slurry edibeneyo idluliswa nge-sieve ye-60-120 ye-mesh;
I-slurry ehluziweyo i-spray granulated ngokusebenzisa i-spray granulation tower. Ubushushu bokungena kwi-spray granulation tower yi-180-260 ℃, kunye nobushushu bokukhutshwa yi-60-120 ℃; ubuninzi bezinto ezixutywe nge-granulated yi-0.85-0.92g / cm3, i-fluidity yi-8-11s / 30g; i-granulated material ihluzwa nge-sieve ye-60-120 ye-mesh ukuze isetyenziswe kamva;
Khetha isikhunta ngokwemilo yemveliso efunwayo, layisha i-granulated material kwi-mold cavity, kwaye wenze ukubunjwa kobushushu begumbi kuxinzelelo lwe-50-200MPa ukufumana umzimba oluhlaza; okanye ubeke umzimba oluhlaza emva kokubunjwa koxinzelelo kwisixhobo sokucinezela i-isostatic, yenza i-isostatic pressing kuxinzelelo lwe-200-300MPa, kwaye ufumane umzimba oluhlaza emva koxinzelelo lwesibini;
Beka umzimba oluhlaza olungiselelwe kula manyathelo angasentla kwisithando somlilo esifunxileyo sokuntywila, kwaye lowo ufanelekileyo yi-silicon carbide bulletproof ceramic egqityiweyo; kule nkqubo ye-sintering ingentla, khupha kuqala isithando somlilo, kwaye xa isidanga se-vacuum sifikelela kwi-3-5 × 10-2 Emva kwe-Pa, igesi ye-inert idluliselwa kwisithando somlilo ukuya kuxinzelelo oluqhelekileyo kwaye emva koko ishushu. Ubudlelwane phakathi kobushushu bokufudumala kunye nexesha: ubushushu begumbi ukuya kwi-800 ℃, iiyure ezingama-5-8, ukugcinwa kobushushu ngeyure eyi-0.5-1, ukusuka kwi-800 ℃ ukuya kwi-2000-2300 ℃, iiyure eziyi-6-9, ukugcinwa kobushushu iiyure ezi-1 ukuya kwezi-2, kwaye emva koko ipholiswe ngesithando somlilo kwaye yehla kwiqondo lokushisa.
I-Microstructure kunye nomda wokuziinkozo we-silicon carbide sintered kuxinzelelo oluqhelekileyo
Ngamafutshane, ii-ceramics eziveliswa yinkqubo yokucofa okutshisayo zinomsebenzi ongcono, kodwa iindleko zemveliso nazo zanda kakhulu; iiseramics ezilungiselelwe sintering engenaxinzelelo zineemfuno eziphezulu zemathiriyeli, ubushushu obuphezulu be-sintering, utshintsho olukhulu lwemveliso, inkqubo entsonkothileyo kunye nokusebenza okuphantsi; Iimveliso ze-ceramic eziveliswe yinkqubo yokusabela kwi-sintering zinoxinaniso oluphezulu, ukusebenza kakuhle kwe-anti-ballistic, kunye neendleko zokulungiselela eziphantsi. Iinkqubo ezahlukeneyo zokulungiselela i-sintering ye-silicon carbide ceramics zineenzuzo zabo kunye nokungalunganga, kwaye iimeko zesicelo ziya kwahluka. Ngowona mgaqo-nkqubo ongcono kakhulu wokukhetha indlela efanelekileyo yokulungiselela ngokwemveliso kwaye ufumane ibhalansi phakathi kweendleko eziphantsi kunye nokusebenza okuphezulu.
Ixesha lokuposa: Oct-29-2024