The carbon zili aliyense sintered chitsanzo fracture ndi yosiyana, ndi mpweya zili A-2.5 awt.% mu osiyanasiyana, kupanga zinthu wandiweyani ndi pafupifupi popanda pores, amene wapangidwa uniformly anagawira pakachitsulo carbide particles ndi free silicon. Ndi kuwonjezeka kwa carbon Kuwonjezera, zili anachita-sintered pakachitsulo carbide ukuwonjezeka pang'onopang'ono, tinthu kukula pakachitsulo carbide ukuwonjezeka, ndi pakachitsulo carbide chikugwirizana wina ndi mzake mu mawonekedwe chigoba. Komabe, kuchulukitsitsa kwa carbon kumatha kupangitsa kuti mpweya wotsalira m'thupi ukhale wotsalira. Pamene mpweya wakuda ukuwonjezeka mpaka 3a, sintering ya chitsanzo sichikwanira, ndipo "interlayers" zakuda zimawonekera mkati.
Mpweya ukakhala ndi silicon yosungunuka, kuchuluka kwake kwa voliyumu ndi 234%, zomwe zimapangitsa kuti mawonekedwe a silicon carbide agwirizane kwambiri ndi zomwe zili mu kaboni. Pamene mpweya wa carbon mu billet ndi wawung'ono, silicon carbide yopangidwa ndi silicon-carbon reaction sikwanira kudzaza pores kuzungulira ufa wa carbon, zomwe zimapangitsa kuti pakhale silicon yaulere mu zitsanzo. Ndi kuchuluka kwa kaboni mu billet, reaction-sintered silicon carbide imatha kudzaza pores kuzungulira ufa wa kaboni ndikulumikiza silicon carbide yoyambirira palimodzi. Panthawi imeneyi, zomwe zili mu silicon yaulere mu zitsanzo zimachepa ndipo kachulukidwe ka thupi la sintered ukuwonjezeka. Komabe, pakakhala mpweya wambiri mu billet, silicon carbide yachiwiri yomwe imapangidwa ndi zomwe zimachitika pakati pa kaboni ndi silicon imazungulira mwachangu tona, zomwe zimapangitsa kuti zikhale zovuta kuti silicon yosungunuka igwirizane ndi tona, zomwe zimapangitsa kuti pakhale mpweya wotsalira m'thupi.
Malinga ndi zotsatira za XRD, gawo la reaction-sintered sic ndi α-SiC, β-SiC ndi silicon yaulere.
M'kati mwa kutentha kwakukulu kwa kutentha, maatomu a carbon amasamukira kumalo oyambirira pa SiC pamwamba β-SiC ndi silicon yosungunuka α-sekondale mapangidwe. Popeza silicon-carbon anachita ndi mmene exothermic anachita ndi kuchuluka kwa kutentha anachita, kuzirala mofulumira pakapita nthawi yochepa mowiriza mkulu kutentha anachita kumawonjezera susaturation wa mpweya kusungunuka pakachitsulo madzi, kuti β-SiC particles precipitated mu mawonekedwe a carbon, potero kuwongolera mawotchi azinthu zakuthupi. Chifukwa chake, kukonzanso kwambewu kwachiwiri kwa β-SiC ndikopindulitsa pakuwongolera mphamvu yopindika. Mu Si-SiC composite system, zomwe zili mu silicon yaulere m'zinthuzo zimachepa ndi kuchuluka kwa kaboni muzinthu zopangira.
Pomaliza:
(1) The mamasukidwe akayendedwe okonzeka zotakasika sintering slurry kuwonjezeka ndi kuchuluka kwa kuchuluka kwa mpweya wakuda; Mtengo wa pH ndi wamchere ndipo pang'onopang'ono ukuwonjezeka.
(2) Ndi kuchuluka kwa kaboni m'thupi, kachulukidwe ndi kupindika kwamphamvu zopangira-sintered zokonzedwa ndikukanikizira zidayamba kuchuluka kenako kutsika. Pamene kuchuluka kwa mpweya wakuda ndi nthawi 2.5 ya kuchuluka koyambirira, mphamvu yopindika ya mfundo zitatu ndi kachulukidwe kakang'ono ka billet wobiriwira pambuyo pochita sintering ndipamwamba kwambiri, zomwe ndi 227.5mpa ndi 3.093g / cm3, motero.
(3) Thupi lokhala ndi kaboni wochuluka litenthedwa, ming'alu ndi "sangweji" zakuda zidzawonekera m'thupi la thupi. Chifukwa cha kusweka kwake ndikuti mpweya wa silicon oxide womwe umapangidwa pochita sintering siwosavuta kutulutsa, umadziunjikira pang'onopang'ono, kupanikizika kumakwera, ndipo zotsatira zake za jacking zimabweretsa kusweka kwa billet. M'dera lakuda la "sandwich" mkati mwa sinter, pali kuchuluka kwa carbon komwe sikukhudzidwa ndi zomwe zimachitika.
Nthawi yotumiza: Jul-10-2023