I-silicon carbide (SiC) ipowder ceramicineenzuzo zamandla obushushu obuphezulu, ukuxhathisa okulungileyo kwe-oxidation, ukumelana nokunxiba okuphezulu kunye nokuzinza kwe-thermal, i-coefficient yokwandisa i-thermal encinci, i-conductivity ephezulu ye-thermal, ukuzinza kakuhle kweekhemikhali, njl. izixhobo, iipatshi ezikwaziyo ukumelana nobushushu, iinxalenye zenjini yenqwelomoya, iinqanawa zokusabela kweekhemikhali, iityhubhu zokutshintsha ubushushu kunye namanye amacandelo oomatshini phantsi kweemeko ezinzima, kwaye sisixhobo sobunjineli esisetyenziswa ngokubanzi.Ayidlali kuphela indima ebalulekileyo kwiinkalo zobugcisa obuphezulu phantsi kophuhliso (ezifana neenjini ze-ceramic, i-spacecraft, njl.), kodwa inemarike ebanzi kunye neendawo zokusetyenziswa eziza kuphuhliswa kumandla akhoyo, isinyithi, oomatshini, izixhobo zokwakha. , ishishini lemichiza kunye nezinye iinkalo.

Iindlela zokulungiselela zei-silicon carbide powderinokwahlulwa ikakhulu ibe ngamacandelo amathathu: indlela yesigaba esiqinileyo, indlela yesigaba solwelo kunye nendlela yesigaba segesi.

1. Indlela yesigaba esiqinileyo

Indlela yesigaba esomeleleyo ikakhulu ibandakanya indlela yokunciphisa i-carbothermal kunye ne-silicon carbon reaction straight method.Iindlela zokunciphisa i-Carbothermal nazo zibandakanya indlela ye-Acheson, indlela yesithando somlilo esithe nkqo kunye nendlela yokuguqula ubushushu obuphezulu.I-silicon carbide powderUkulungiswa kwalungiselelwa ekuqaleni yindlela ye-Acheson, usebenzisa i-coke ukunciphisa i-silicon dioxide kwiqondo lokushisa eliphezulu (malunga ne-2400 ℃), kodwa umgubo ofunyenwe ngale ndlela unobungakanani obukhulu be-particle (> 1mm), idla amandla amaninzi, kwaye inkqubo intsonkothile.Kwiminyaka yoo-1980, kwavela izixhobo ezitsha zokwenza i-β-SiC powder, ezifana nesithando somlilo esithe nkqo kunye nesiguquli sobushushu obuphezulu.Njengoko i-polymerization esebenzayo kunye nekhethekileyo phakathi kwe-microwave kunye nezinto zekhemikhali eziqinileyo ziye zacaciswa ngokuthe ngcembe, itekhnoloji yokudibanisa umgubo we-sic ngokufudumeza i-microwave iye yakhula ngokukhula.Indlela ye-silicon carbon reaction direct reaction ikwabandakanya self-propagating high temperatures synthesis (SHS) kunye ne-mechanical alloying method.Indlela ye-SHS yokunciphisa i-synthesis isebenzisa i-exothermic reaction phakathi kwe-SiO2 kunye ne-Mg ukwenza ukungabikho kobushushu.Ii-silicon carbide powderefunyenwe ngale ndlela inobunyulu obuphezulu kunye nobukhulu be-particle encinci, kodwa i-Mg kwimveliso kufuneka isuswe ngeenkqubo ezilandelayo ezifana ne-pickling.

2 indlela yesigaba solwelo

Indlela yesigaba solwelo ikakhulu ibandakanya indlela ye-sol-gel kunye nendlela yokubola kwe-polymer.Indlela ye-Sol-gel yindlela yokulungiselela i-gel equkethe i-Si kunye ne-C ngenkqubo efanelekileyo ye-sol-gel, kwaye emva koko i-pyrolysis kunye nokunciphisa i-carbothermal ephezulu yokushisa ukufumana i-silicon carbide.Ukubola kobushushu obuphezulu bepolymer ephilayo bubuchwephesha obusebenzayo bokulungiselela i-silicon carbide: enye kukufudumeza i-gel polysiloxane, ukusabela kokubola ukukhulula ii-monomers ezincinci, kwaye ekugqibeleni zenze i-SiO2 kunye ne-C, kwaye emva koko ngokusabela kokunciphisa i-carbon ukuvelisa i-SiC powder;Enye kukutshisa i-polysilane okanye i-polycarbosilane ukukhulula ii-monomer ezincinci zenze i-skeleton, kwaye ekugqibeleni zenze i-skeleton.i-silicon carbide powder.

3 Indlela yesigaba segesi

Okwangoku, i-gas phase synthesis yei-silicon carbideI-ceramic ultrafine powder ikakhulu isebenzisa i-gas phase deposition (CVD), i-Plasma Induced CVD, i-Laser Induced CVD kunye nobunye ubuchwepheshe bokubola izinto eziphilayo kwiqondo lokushisa eliphezulu.I-powder efunyenweyo ineenzuzo zokucoceka okuphezulu, ubungakanani bencinci encinci, i-particle agglomeration encinci kunye nokulawulwa lula kwamacandelo.Yindlela ehamba phambili ngoku, kodwa ngexabiso eliphezulu kunye nesivuno esiphantsi, akulula ukufikelela kwimveliso yobuninzi, kwaye ifaneleke ngakumbi ukwenza izinto zebhubhoratri kunye neemveliso ezineemfuno ezizodwa.

Okwangoku, ii-silicon carbide powderesetyenziswayo ikakhulu i-submicron okanye inqanaba le-nano powder, kuba ubungakanani besuntswana lomgubo lincinci, umsebenzi omphezulu ophezulu, ke ingxaki ephambili kukuba umgubo kulula ukuvelisa i-agglomeration, kuyimfuneko ukuguqula umphezulu womgubo ukunqanda okanye ukunqanda. i-agglomeration yesibini yomgubo.Okwangoku, iindlela zokusasazwa kwe-SiC powder zibandakanya ikakhulu ezi ndidi zilandelayo: ukuguqulwa komphezulu wamandla aphezulu, ukuhlamba, ukunyangwa kwe-disperant of powder, ukuguqulwa kwe-inorganic coating, ukuguqulwa kwezinto eziphilayo.