Idethi :2022-05-28  Umthombo: I-Fiber Composites

Isakhiwo se-lattice sekristalu efanelekile ye-graphite singokwesistimu yekristalu ene-hexagonal, okuyisakhiwo esigqagqene sezendlalelo eziningi esakhiwe ama-athomu ekhabhoni esakhiweni senethiwekhi esiyindandatho esinamalungu ayisithupha. Eringini enamalungu ayisithupha, ama-athomu ekhabhoni asesimweni se-sp 2 hybrid

Isakhiwo esiyisisekelo

Isakhiwo se-lattice sekristalu efanelekile ye-graphite singokwesistimu ye-crystal ene-hexagonal, eyakhiwe ama-athomu ekhabhoni ahlanganiswe nesakhiwo senethiwekhi yendandatho yamalungu ayisithupha. Eringini enamalungu ayisithupha, ama-athomu ekhabhoni ayi-sp 2 hybridization ekhona. Ku-sp2 hybridization, kukhona i-electron engu-1 2s kanye ne-2 2p electron hybridization, okwenza amabhondi amathathu alinganayo o aqinile, ibanga lebhondi lingu-0.1421nm, isilinganiso samandla ebhondi ngu-627kJ/mol nama-engeli ebhondi angu-120 elinye nelinye.

Ama-orbitals angu-2p asele endizeni efanayo ancike endizeni lapho amabhondi amathathu etholakala khona, futhi amabhondi e-N ama-athomu ekhabhoni akha i-N-bond ayahambisana futhi ayahambisana ukuze akhe i-N enkulu. - isibopho; Ama-electron angewona owasendaweni ku-n electron angahamba ngokukhululekile ahambisane nendiza, ayinikeze izakhiwo zokuqhuba. Bangakwazi ukumunca ukukhanya okubonakalayo, benze i-graphite ibe mnyama. Amandla e-van der Waals phakathi kwezingqimba zegraphite mancane kakhulu kune-valence bond force ngaphakathi kwezingqimba. Isikhala phakathi kwezendlalelo ngu-0.3354nm, futhi amandla ebhondi angu-5.4kJ/mol. Izendlalelo ze-graphite zinyakaziswa ngohhafu we-symmetry ene-hexagonal futhi ziphindaphindwa kuzo zonke ezinye izendlalelo, zakha i-ABAB.

Isakhiwo [4], nokusinikeza amandla okuzithambisa nekhono langaphakathi le-interlayer, njengoba kukhonjisiwe kuMfanekiso 2-5. I-Carbon fiber iyi-microcrystalline itshe-ink material etholakala ku-organic fiber ngokufaka i-carbonization kanye ne-graphitization.

I-microstructure ye-carbon fiber ifana neye-graphite yokwenziwa, eyingxenye ye-polycrystalline chaotic graphite. Umehluko ovela esakhiweni se-graphite usekuhumusheni okungajwayelekile kanye nokuzungezisa phakathi kwezingqimba ze-athomu (bona Umfanekiso 2-6). Isibopho sokuxhumana senethiwekhi yezinto eziyisithupha siboshelwe ongqimbeni lwe-athomu lwe - oluhambisana ngokuyisisekelo ne-fiber axis. Ngakho-ke, ngokuvamile kukholakala ukuthi i-carbon fiber yakhiwe isakhiwo se-graphite esingahlelekile eduze nokuphakama kwe-axis ye-fiber, okuholela ku-axial tensile modulus ephezulu kakhulu. Isakhiwo se-lamellar se-graphite sine-anisotropy ebalulekile, okwenza izici zayo ezibonakalayo zibonise i-anisotropy.

Izakhiwo kanye nokusetshenziswa kwe-carbon fiber

I-Carbon fiber ingahlukaniswa ibe i-filament, i-staple fiber, ne-staple fiber. Izakhiwo zemishini zihlukaniswe ngohlobo olujwayelekile kanye nohlobo olusebenza kakhulu. Amandla we-Carbon fiber ejwayelekile yi-1000 MPa, i-modulus imayelana ne-10OGPa. I-carbon fiber esebenza kahle kakhulu ihlukaniswe yaba uhlobo lwamandla aphezulu (amandla angu-2000MPa, i-modulus 250GPa) kanye nemodeli ephezulu (imoduli engaphezu kuka-300GPa). Amandla angaphezu kuka-4000MPa abizwa nangokuthi uhlobo lwamandla aphezulu kakhulu; Labo abane-modulus enkulu kune-450GPa babizwa ngamamodeli aphezulu kakhulu. Ngokuthuthuka komkhakha we-aerospace kanye nezindiza, amandla aphezulu kanye ne-carbon fiber elongation ephezulu, futhi ubude bayo bungaphezu kuka-2%. Inani elikhulu i-polypropylene iso PAN-based carbon fiber. I-Carbon fiber inamandla aphezulu e-axial kanye ne-modulus, akukho ukukhasa, ukumelana nokukhathala okuhle, ukushisa okukhethekile kanye nokuhamba kukagesi phakathi kokungeyona insimbi nensimbi, i-coefficient encane yokwanda okushisayo, ukumelana nokugqwala okuhle, ukuminyana kwefayibha ephansi, kanye nokudluliswa okuhle kwe-X-ray. Kodwa-ke, ukumelana kwayo komthelela kumpofu futhi kulula ukulimaza, i-oxidation ivela ngaphansi kwesenzo se-asidi eqinile, futhi i-carbonization yensimbi, i-carburization, kanye ne-electrochemical corrosion kwenzeka uma ihlanganiswa nensimbi. Ngenxa yalokho, i-carbon fiber kufanele iphathwe phezulu ngaphambi kokusetshenziswa.