Ukusabela sintering
Ukusabela sinteringi-silicon carbide ceramicinqubo yokukhiqiza ihlanganisa i-ceramic compacting, i-sintering flux infiltration agent, ukulungiswa komkhiqizo we-ceramic sintering, ukulungiswa kwe-silicon carbide ngokhuni lwe-ceramic nezinye izinyathelo.
I-Reaction sintering silicon carbide nozzle
Okokuqala, i-80-90% ye-ceramic powder (ehlanganiswe yimpushana eyodwa noma ezimbili zei-silicon carbide powderkanye ne-boron carbide powder), i-3-15% ye-carbon source powder (ehlanganiswe ne-carbon black ne-phenolic resin eyodwa noma ezimbili) kanye ne-5-15% ye-ejenti yokubumba (i-phenolic resin, i-polyethylene glycol, i-hydroxymethyl cellulose noma ipharafini) ixutshwe ngokulinganayo. usebenzisa umshini wokugaya ukuze uthole impushana exubile, efafazwa yomisiwe futhi igaywe, bese icindezelwa esikhunjini ukuze uthole i-ceramic compact enezinhlobonhlobo ezihlukahlukene. amajamo.
Okwesibili, i-60-80% ye-silicon powder, i-3-10% ye-silicon carbide powder kanye ne-37-10% ye-boron nitride powder ixutshwe ngokulinganayo, futhi icindezelwe ekubunjweni ukuze kutholwe i-ejenti yokungena e-sintering flux.
I-ceramic compact kanye ne-sintered infiltrant compact bese ihlanganiswa ndawonye, futhi izinga lokushisa likhuphukela ku-1450-1750 ℃ esithandweni somlilo esine-vacuum degree engekho ngaphansi kuka-5 × 10-1 Pa yokushisa nokugcina ukushisa kwe-1-3. amahora ukuthola umkhiqizo wokusabela we-ceramic we-ceramic. Izinsalela ezingenayo ebusweni be-ceramic e-sintered zisuswa ngokuthepha ukuze kutholwe ishidi le-ceramic elicinene, futhi ukuma kwangempela kwe-compact kugcinwa.
Ekugcineni, inqubo yokusabela ye-sintering iyamukelwa, okungukuthi, i-silicon ewuketshezi noma i-silicon alloy enomsebenzi wokusabela ekushiseni okuphezulu ingena endaweni engenalutho ye-ceramic equkethe i-carbon ngaphansi kwesenzo se-capillary force, futhi isabela nekhabhoni ekuyo ukuze yakhe i-silicon carbide, okuyinto izokhula ngevolumu, futhi ama-pores asele agcwele i-silicon eyisisekelo. I-ceramic engenalutho engenalutho ingaba i-carbon ehlanzekile noma i-silicon carbide/i-carbon-based composite material. Owokuqala utholakala ngokuphulukisa kanye ne-pyrolyzing i-organic resin, i-pore yangaphambili kanye ne-solvent. Lokhu kokugcina kutholakala nge-pyrolyzing silicon carbide particles/resin-based composite materials ukuthola i-silicon carbide/carbon-based composite materials, noma ngokusebenzisa i-α-SiC kanye ne-carbon powder njengezinto zokuqala nokusebenzisa inqubo yokucindezela noma yokujova ukuze uthole inhlanganisela. impahla.
Ukucula okungenangcindezi
Inqubo ye-sintering engenasici ye-silicon carbide ingahlukaniswa ibe yi-solid-phase sintering kanye ne-liquid-phase sintering. Eminyakeni yamuva, ucwaningo oni-silicon carbide ceramicsekhaya naphesheya ikakhulukazi igxile liquid-isigaba sintering. Inqubo yokulungiselela i-ceramic yile: ukugaya okuxubile kwebhola–>i-spray granulation–>ukucindezela okomile–>ukuqiniswa komzimba okuluhlaza–>ukufakwa kwe-vacuum sintering.
Imikhiqizo ye-silicon carbide engenasici
Engeza izingxenye ezingu-96-99 ze-silicon carbide ultrafine powder (50-500nm), izingxenye ezingu-1-2 ze-boron carbide ultrafine powder (50-500nm), 0.2-1 izingxenye ze-nano-titanium boride (30-80nm), izingxenye ezingu-10-20 ye-phenolic resin encibilikayo emanzini, kanye nezingxenye ezingu-0.1-0.5 zokusebenza kahle kakhulu dispersant to the ball mill for ball milling and mix for 24 hours, and put the mix slurry into a mixing barrel for 2 hours to remove Bubbles in the slurry.
Ingxube engenhla ifuthwe embhoshongweni we-granulation, futhi i-granulation powder enezinhlayiya ezinhle ze-morphology, i-fluidity enhle, ububanzi bezinhlayiyana ezincane zokusabalalisa kanye nomswakama ophakathi kutholakala ngokulawula ukucindezela kwesifutho, izinga lokushisa lokungenisa umoya, izinga lokushisa lomoya kanye nosayizi wezinhlayiyana ze-spray sheet. Ukuguqulwa kwefrikhwensi ye-centrifugal ngu-26-32, izinga lokushisa lokungenisa umoya lingama-250-280 ℃, izinga lokushisa lokukhipha umoya liyi-100-120 ℃, kanye nomfutho we-slurry inlet ngu-40-60.
I-granulation powder engenhla ifakwa esikhunjini se-carbide esisikiwe ukuze sicindezelwe ukuze kutholwe umzimba oluhlaza. Indlela yokucindezela ingcindezi ye-bidirectional, futhi ithuluzi lomshini lokucindezela amathani angama-150-200 amathani.
Umzimba oluhlaza ocindezelwe ufakwa kuhhavini owomisa ukuze womiswe futhi uphulukiswe ukuze uthole umzimba oluhlaza onamandla omzimba oluhlaza omuhle.
Umzimba oluhlaza ophulukisiwe ongenhla ubekwe ku-ai-graphite cruciblefuthi ihlelwe ngokuseduze futhi ngobunono, bese i-graphite crucible enomzimba oluhlaza ibekwe esithandweni sokushisa esishisayo se-vacuum sintering sokudubula. Izinga lokushisa lokudubula liyi-2200-2250 ℃, futhi isikhathi sokufaka singamahora angu-1-2. Okokugcina, kutholakala izitsha zobumba ze-silicon carbide ezisebenza kahle ezingenasicindezelo.
I-solid-phase sintering
Inqubo ye-sintering engenasici ye-silicon carbide ingahlukaniswa ibe yi-solid-phase sintering kanye ne-liquid-phase sintering. I-Liquid-phase sintering idinga ukungezwa kwezithasiselo ze-sintering, ezifana ne-Y2O3 kanambambili nezithasiselo ze-ternary, ukwenza i-SiC nezinto zayo eziyinhlanganisela yethule i-liquid-phase sintering futhi ifinyelele ukuminyana ezingeni lokushisa eliphansi. Indlela yokulungiselela ye-solid-phase sintered silicon carbide ceramics ihlanganisa ukuxuba kwezinto ezingavuthiwe, i-spray granulation, ukubumba, kanye ne-vacuum sintering. Inqubo ethile yokukhiqiza imi kanje:
U-70-90% we-submicron α silicon carbide (200-500nm), 0.1-5% we-boron carbide, u-4-20% we-resin, kanye no-5-20% we-organic binder afakwa ku-mixer futhi yengezwe ngamanzi ahlanzekile ukuze abemanzi. ukuxuba. Ngemuva kwamahora angu-6-48, i-slurry ehlanganisiwe idluliswa ngesihlungo se-60-120 mesh;
I-slurry ehlungiwe ifafazwa nge-granulation ngombhoshongo we-spray granulation. Izinga lokushisa lokungena lombhoshongo we-spray granulation ngu-180-260 ℃, futhi izinga lokushisa lokuphuma liyi-60-120 ℃; ukuminyana ngobuningi bezinto ezinamaqabunga angu-0.85-0.92g/cm3, uketshezi kungu-8-11s/30g; i-granulated material ihlungwa ngesihlungo se-60-120 mesh ukuze sisetshenziswe kamuva;
Khetha isikhunta ngokuya ngesimo osifunayo somkhiqizo, layisha i-granulated material emgodini wesikhunta, futhi wenze ukubunjwa kokucindezelwa kwezinga lokushisa kwegumbi ngengcindezi engu-50-200MPa ukuze uthole umzimba oluhlaza; noma ubeke umzimba oluhlaza ngemva kokubunjwa kokucindezelwa kumshini wokucindezela we-isostatic, wenze ukucindezela kwe-isostatic ngokucindezela kwe-200-300MPa, futhi uthole umzimba oluhlaza ngemva kokucindezela kwesibili;
Faka umzimba oluhlaza olungiselelwe ezinyathelweni ezingenhla esithandweni se-vacuum sintering ukuze usishise, futhi esifanelekayo yi-ceramic eqediwe ye-silicon carbide bulletproof; kule nqubo yokushisa engenhla, qala ukhiphe isithando somlilo, futhi lapho i-vacuum degree ifinyelela ku-3-5 × 10-2 Ngemva kwe-Pa, igesi ye-inert idluliselwa esithandweni somlilo ukuze icindezeleke evamile bese iyashiswa. Ubudlelwano phakathi kokushisa kokushisa nesikhathi: izinga lokushisa legumbi ukuya ku-800 ℃, amahora angama-5-8, ukulondolozwa kokushisa kwehora elingu-0.5-1, ukusuka ku-800 ℃ kuye ku-2000-2300 ℃, amahora angama-6-9, ukugcinwa kokushisa amahora angama-1 kuye kwayi-2, bese ipholiswa ngesithando somlilo futhi yehla ekamelweni lokushisa.
I-Microstructure kanye nomngcele wokusanhlamvu we-silicon carbide ofakwe ngengcindezi evamile
Ngamafuphi, ama-ceramics akhiqizwa inqubo yokucindezela okushisayo inokusebenza okungcono, kodwa izindleko zokukhiqiza nazo zanda kakhulu; izitsha zobumba ezilungiselelwe i-sintering engenasici zinezidingo eziphezulu zempahla eluhlaza, izinga lokushisa eliphezulu le-sintering, izinguquko ezinkulu zosayizi womkhiqizo, inqubo eyinkimbinkimbi kanye nokusebenza okuphansi; imikhiqizo ye-ceramic ekhiqizwa inqubo ye-reaction sintering inokuminyana okuphezulu, ukusebenza okuhle kwe-anti-ballistic, kanye nezindleko eziphansi zokulungiselela. Izinqubo ezihlukahlukene zokulungiselela i-sintering ye-silicon carbide ceramics zinezinzuzo zazo kanye nokubi, futhi izimo zesicelo nazo zizohluka. Kuyinqubomgomo engcono kakhulu ukukhetha indlela efanele yokulungiselela ngokusho komkhiqizo futhi uthole ibhalansi phakathi kwezindleko eziphansi nokusebenza okuphezulu.
Isikhathi sokuthumela: Oct-29-2024