I-silicon nitride – izinto zobumba ezakhiwe kahle kakhulu

I-ceramics ekhethekile ibhekisela ekilasini le-ceramics elinezakhiwo ezikhethekile zemishini, zomzimba noma zamakhemikhali, izinto zokusetshenziswa ezisetshenziswayo kanye nobuchwepheshe bokukhiqiza obudingekayo kuhluke kakhulu ku-ceramics ezivamile kanye nentuthuko. Ngokwezici kanye nokusetshenziswa, i-ceramics ekhethekile ingahlukaniswa ngezigaba ezimbili: i-ceramics yesakhiwo kanye ne-ceramics esebenzayo. Phakathi kwazo, i-ceramics yesakhiwo ibhekisela ku-ceramics engasetshenziswa njengezinto zokwakha zobunjiniyela, ngokuvamile ezinamandla aphezulu, ubulukhuni obuphezulu, i-modulus ephezulu yokunwebeka, ukumelana nokushisa okuphezulu, ukumelana nokuguguleka, ukumelana nokugqwala, ukumelana nokushiswa kwe-oxidation, ukumelana nokushaqeka kokushisa nezinye izici.

Kunezinhlobo eziningi ze-ceramics zesakhiwo, izinzuzo kanye nokungalungi, futhi isiqondiso sokusetshenziswa kwezinzuzo kanye nokungalungi sihlukile, phakathi kwazo "i-silicon nitride ceramics" ngenxa yokulinganisela kokusebenza kuzo zonke izici, eyaziwa njengokusebenza okuhle kakhulu okuphelele emndenini we-ceramics zesakhiwo, futhi inobubanzi obukhulu bezicelo.

Izinzuzo ze-silicon nitride ceramics

I-silicon nitride (Si3N4) ingahlukaniswa ibe ama-compound e-covalent bond, kanye ne-[SiN4] 4-tetrahedron njengeyunithi yesakhiwo. Izikhundla ezithile zama-athomu e-nitrogen ne-silicon zingabonakala esithombeni esingezansi, i-silicon iphakathi kwe-tetrahedron, kanti izikhundla zama-vertices amane e-tetrahedron zihlala ama-athomu e-nitrogen, bese kuthi yonke i-tetrahedron emithathu ihlanganyele i-athomu eyodwa, iqhubekela phambili esikhaleni esinezinhlangothi ezintathu. Ekugcineni, kwakheka isakhiwo senethiwekhi. Izakhiwo eziningi ze-silicon nitride zihlobene nalesi sakhiwo se-tetrahedral.

Kunezinhlobo ezintathu ze-silicon nitride ezi-crystalline, okuyizigaba ze-α, β kanye ne-γ, lapho izigaba ze-α kanye ne-β ziyizinhlobo ezivame kakhulu ze-silicon nitride. Ngenxa yokuthi ama-athomu e-nitrogen ahlanganiswe ngokuqinile, i-silicon nitride inamandla amahle aphezulu, ubulukhuni obuphezulu kanye nokumelana nokushisa okuphezulu, kanti ubulukhuni bungafinyelela ku-HRA91 ~ 93; Ukuqina okuhle kokushisa, kungamelana nokushisa okuphezulu okungu-1300 ~ 1400℃; Ukusabela okuncane kwamakhemikhali ngezinto ze-carbon nezensimbi kuholela ku-coefficient ephansi yokungqubuzana; Iyazigcoba futhi ngenxa yalokho imelana nokuguga; Ukumelana nokugqwala kunamandla, ngaphezu kwe-hydrofluoric acid, ayisabelani namanye ama-asidi angaphili, izinga lokushisa eliphezulu liphinde libe nokumelana nokushiswa kwe-oxidation; Iphinde ibe nokumelana okuhle nokushaqeka kokushisa, ukupholisa okubukhali emoyeni bese ukushisa okubukhali kungabhidliki; Ukukhukhuleka kwe-silicon nitride ceramics kuncipha ekushiseni okuphezulu, futhi ukuguquguquka kwepulasitiki okuhamba kancane kuncane ngaphansi kwesenzo sokushisa okuphezulu kanye nomthwalo oqinile.

Ngaphezu kwalokho, i-silicon nitride ceramics nayo inamandla aphezulu athile, imodi ephezulu ethile, ukuqhuba okuphezulu kokushisa, izakhiwo zikagesi ezinhle kakhulu nezinye izinzuzo, ngakho-ke inenani elikhethekile lokusetshenziswa endaweni ebucayi njengokushisa okuphezulu, isivinini esikhulu, imithombo eqinile yokubola, futhi ibhekwa njengenye yezinto zokwakha ze-ceramic ezithembisayo kakhulu zokuthuthukiswa nokusetshenziswa, futhi ivame ukuba yisinqumo sokuqala ezinhlelweni eziningi ezidinga ukuhlolwa.