I-Silicon nitride - i-ceramics yesakhiwo esebenza kahle kakhulu

I-ceramics ekhethekile ibhekisela ekilasini le-ceramics enezakhiwo ezikhethekile zemishini, ngokomzimba noma amakhemikhali, izinto zokusetshenziswa ezisetshenziswayo kanye nobuchwepheshe bokukhiqiza obudingekayo buhluke kakhulu kuma-ceramics ajwayelekile kanye nentuthuko. Ngokwezici kanye nokusetshenziswa, i-ceramics ekhethekile ingahlukaniswa ngezigaba ezimbili: i-ceramics yesakhiwo kanye ne-ceramics esebenzayo. Phakathi kwazo, i-ceramics yesakhiwo ibhekisela kuma-ceramics angasetshenziswa njengezinto zokwakha zobunjiniyela, ngokuvamile ezinamandla amakhulu, ukuqina okuphezulu, i-modulus ephezulu yokunwebeka, ukumelana nokushisa okuphezulu, ukumelana nokugqoka, ukumelana nokugqwala, ukumelana ne-oxidation, ukumelana nokushaqeka okushisayo nezinye izici.

Kunezinhlobo eziningi ze-ceramics yesakhiwo, izinzuzo kanye nokubi, futhi isiqondiso sokusetshenziswa kwezinzuzo nezinkinga zihlukile, phakathi kwazo "i-silicon nitride ceramics" ngenxa yebhalansi yokusebenza kuzo zonke izici, eyaziwa ngokuthi ukusebenza okuhle kakhulu okuphelele umndeni we-ceramics yesakhiwo, futhi unohlu olubanzi kakhulu lwezinhlelo zokusebenza.

Izinzuzo ze-silicon nitride ceramics

I-Silicon nitride (Si3N4) ingahlukaniswa ibe izinhlanganisela zebhondi ehlangene, ne-[SiN4] 4-tetrahedron njengeyunithi yesakhiwo. Izikhundla ezithile zama-athomu e-nitrogen ne-silicon zingabonakala emfanekisweni ongezansi, i-silicon iphakathi nendawo ye-tetrahedron, futhi izikhundla zama-vertices ezine ze-tetrahedron zithathwa ama-athomu e-nitrogen, bese kuthi njalo ama-tetrahedron amathathu ahlanganyela i-athomu eyodwa, njalo. ukunwebeka endaweni enezinhlangothi ezintathu. Ekugcineni, isakhiwo senethiwekhi siyakhiwa. Izakhiwo eziningi ze-silicon nitride zihlobene nalesi sakhiwo se-tetrahedral.

Kunezinhlaka ezintathu zecrystalline ze-silicon nitride, okuyizigaba ezingu-α, β kanye no-γ, lapho izigaba zika-α kanye no-β ziyizinhlobo ezivame kakhulu ze-silicon nitride. Ngenxa yokuthi ama-athomu e-nitrogen ahlanganiswe ngokuqinile, i-silicon nitride inamandla amahle aphezulu, ukuqina okuphezulu nokumelana nokushisa okuphezulu, futhi ubulukhuni bungafinyelela ku-HRA91~93; Ukuqina okuhle kokushisa, kungamelana nezinga lokushisa eliphakeme lika-1300 ~ 1400℃; Ukusabela kwamakhemikhali amancane nge-carbon nezakhi zensimbi kuholela ku-coefficient ephansi ye-friction; Iyazigcoba ngakho-ke imelana nokugqoka; Ukumelana nokugqwala kunamandla, ngaphezu kwe-hydrofluoric acid, ayisabelani namanye ama-inorganic acid, izinga lokushisa eliphezulu libuye libe nokuphikiswa kwe-oxidation; Iphinde ibe nokumelana nokushaqeka okuhle kwe-thermal, ukupholisa okubukhali emoyeni bese ukushisa okubukhali ngeke kudilike; Ukukhasa kwe-silicon nitride ceramics kuncipha ekushiseni okuphezulu, futhi ukuwohloka kwepulasitiki okuhamba kancane kuncane ngaphansi kwesenzo sokushisa okuphezulu nomthwalo ongashintshi.

Ngaphezu kwalokho, izitsha zobumba ze-silicon nitride nazo zinamandla athile aphezulu, imodi ethize ephezulu, ukuguquguquka okuphezulu kwe-thermal, izakhiwo ezinhle kakhulu zikagesi nezinye izinzuzo, ngakho-ke inenani elikhethekile lesicelo endaweni eshisayo efana nokushisa okuphezulu, isivinini esikhulu, imidiya eqinile egqwalayo, futhi ibhekwa njengenye yezinto zokwakha ze-ceramic ezithembisayo kakhulu ekuthuthukisweni nasekusetshenzisweni, futhi ngokuvamile iba yinketho yokuqala ezinhlelweni eziningi ezidinga ukuhlolwa.