I-Silicon nitride-i-ceramics zolwakhiwo ezinowona msebenzi ubalaseleyo

I-ceramics ezikhethekileyo zibhekisela kwiklasi yeekeramics ezinomatshini okhethekileyo, izinto eziphathekayo okanye iikhemikhali, izinto ezisetyenzisiweyo ezisetyenzisiweyo kunye nobuchwepheshe bokuvelisa obufunekayo buhluke kakhulu kwi-ceramics eqhelekileyo kunye nophuhliso. Ngokweempawu kunye nokusetyenziswa, ii-ceramics ezikhethekileyo zingahlulwa zibe ngamacandelo amabini: i-ceramics yesakhiwo kunye neekeramics ezisebenzayo. Phakathi kwazo, iiseramics zolwakhiwo zibhekisa kwiikeramics ezinokusetyenziswa njengezixhobo zobunjineli bobunjineli, ezidla ngokuba namandla aphezulu, ukuqina okuphezulu, imodyuli ephezulu yelastiki, ukumelana nobushushu obuphezulu, ukumelana nokunxiba, ukumelana nokugqwala, ukumelana ne-oxidation, ukuxhathisa ukothuka kwe-thermal kunye nezinye iimpawu.

Kukho iintlobo ezininzi zeeseramics zesakhiwo, izinto eziluncedo kunye nezingeloncedo, kwaye isalathiso sesicelo sezinto eziluncedo kunye nezingeloncedo zahlukile, phakathi kwazo "i-silicon nitride ceramics" ngenxa yolungelelwaniso lwentsebenzo kuzo zonke iinkalo, yaziwa njengowona msebenzi ugqwesileyo kusapho lwe-ceramics, kwaye inoluhlu olubanzi kakhulu lwezicelo.

Izinto ezilungileyo ze-silicon nitride ceramics

I-Silicon nitride (i-Si3N4) inokwahlulwa ibe yi-covalent bond compounds, kunye ne- [SiN4] 4-tetrahedron njengeyunithi yesakhiwo. Izikhundla ezithile ze-nitrogen kunye ne-athomu ye-silicon inokubonwa kulo mzobo ungezantsi, i-silicon isembindini we-tetrahedron, kwaye izikhundla zee-vertices ezine ze-tetrahedron zithathwe yi-athomu ye-nitrogen, kwaye emva koko zonke ezintathu ze-tetrahedron zabelana nge-athomu enye, zihlala zikhula kwisithuba se-dimensional ezintathu. Ekugqibeleni, isakhiwo sothungelwano senziwe. Uninzi lweempawu ze-silicon nitride zihambelana nesi sakhiwo se-tetrahedral.

Kukho izakhiwo ezintathu ze-crystalline ze-silicon nitride, eziyi-α, i-β kunye ne-γ izigaba, apho izigaba ze-α kunye ne-β zizona zindlela eziqhelekileyo ze-silicon nitride. Ngenxa yokuba i-athomu ye-nitrogen idityaniswe ngokuqinileyo, i-silicon nitride inamandla aphezulu, ubunzima obuphezulu kunye nokumelana nokushisa okuphezulu, kunye nokuqina kunokufikelela kwi-HRA91 ~ 93; Ukuqina okuhle kwe-thermal, kunokumelana nobushushu obuphezulu be-1300 ~ 1400℃; Ukusabela kweekhemikhali ezincinci kunye nekhabhoni kunye nezinto zetsimbi zikhokelela kwi-coefficient ephantsi yokuxubana; Iyazithambisa kwaye ngenxa yoko iyamelana nokunxiba; Ukumelana ne-Corrosion kunamandla, ngaphezu kwe-hydrofluoric acid, ayisebenzi kunye nezinye i-inorganic acids, ubushushu obuphezulu bunokumelana ne-oxidation; Ikwanayo nokumelana nokothuka kwe-thermal, ukupholisa okubukhali emoyeni kwaye emva koko ukufudumeza okubukhali akuyi kudilika; I-creep ye-silicon nitride ceramics iyancipha kwiqondo lokushisa eliphezulu, kwaye i-deformation yeplastiki encinci incinci phantsi kwesenzo sokushisa okuphezulu kunye nomthwalo osisigxina.

Ukongeza, i-silicon nitride ceramics ikwanawo amandla athile aphezulu, imowudi ephezulu ephezulu, i-thermal conductivity ephezulu, iipropathi ezigqwesileyo zombane kunye nezinye izinto eziluncedo, ke inexabiso elikhethekileyo lesicelo kwindawo egqithileyo efana nobushushu obuphezulu, isantya esiphezulu, imidiya eyonakalisayo eyomeleleyo, kwaye ithathwa njengenye yezona zinto zithembisayo ze-ceramic zophuhliso kunye nokusetyenziswa, kwaye ihlala ibe lukhetho lokuqala kwizicelo ezininzi ezifuna ukuvavanywa.