Umhla :2022-05-28  Umthombo: Ii-Fiber Composites

I-lattice structure ye-crystal ye-graphite efanelekileyo ye-hexagonal crystal system, eyi-multi-layer overlapping structure eyenziwe ngee-athom zekhabhoni kwisakhiwo sothungelwano esinamalungu amathandathu. Kwindandatho yamalungu amathandathu, iiathomu zekhabhoni zikwimo ye-sp 2 hybrid

Ulwakhiwo olusisiseko

Ubume be-lattice ye-crystal ye-graphite efanelekileyo ye-hexagonal crystal system, eyenziwe ngee-athomu zekhabhoni ezihlanganiswe nesakhiwo sothungelwano esinamalungu amathandathu. Kwiringi enamalungu amathandathu, iiathom zekhabhoni zi-sp 2 hybridization ikhona. Kwi-sp2 hybridization, kukho i-electron ye-1 2s kunye ne-2 2p ye-electron hybridization, eyenza i-elektroni ezintathu ezilinganayo ezilinganayo, umgama webhondi yi-0.1421nm, i-avareji yamandla ebhondi yi-627kJ / mol kunye nee-engile zebhondi ziyi-120 enye kwenye.

I-orbitals eseleyo ye-2p ecocekileyo kwinqwelo-moya enye i-perpendicular kwinqwelomoya apho iibhondi ezintathu zikhoyo, kunye ne-N-bond ye-athomu ye-carbon eyenza i-N-bond ihambelana enye kwenye kwaye idibanisa ukwenza i-N enkulu. -ibhondi; Ii-electron ezingezizo zasekuhlaleni kwi-electron n zinokuhamba ngokukhululekileyo ngokuhambelana nendiza, zinike iipropati zokuqhuba. Ziyakwazi ukufunxa ukukhanya okubonakalayo, zenze igraphite ibe mnyama. Amandla e-van der Waals phakathi kwamaleko egraphite angaphantsi kakhulu kune-valence bond force ngaphakathi kweeleya. Isithuba phakathi kwemigangatho yi-0.3354nm, kwaye amandla ebhondi yi-5.4kJ / mol. Iileya zegraphite zigxadazela ngesiqingatha se-symmetry enehexagonal kwaye ziphinda-phinda kuwo wonke omnye umaleko, zenza i-ABAB.

Ulwakhiwo [4], kunye nokunika i-self-lubrication kunye ne-interlayer isakhono sangaphakathi, njengoko kubonisiwe kwi-Figure 2-5. Ifayibha yeCarbon yi-microcrystalline stone-inki material efunyenwe kwi-organic fiber nge-carbonization kunye ne-graphitization.

I-microstructure ye-carbon fiber ifana ne-graphite eyenziweyo, eyesakhiwo se-polycrystalline chaotic graphite. Umahluko kulwakhiwo lwegraphite ilele kuguqulelo olungaqhelekanga kunye nokujikeleza phakathi kwamaleko eathom (jonga uMfanekiso 2-6). Uthungelwano-element ezintandathu covalent bond ibotshelelwe umaleko atomic of - nto leyo ngokusisiseko parallel kwi axis ifayibha. Ke ngoko, kukholelwa ngokubanzi ukuba i-carbon fiber yenziwe ngolwakhiwo lwegraphite ephazamisekileyo ecaleni kobude be-axis yefiber, ekhokelela kwimodyuli ephezulu kakhulu ye-axial tensile. Isakhiwo se-lamellar se-graphite sine-anisotropy ebalulekileyo, eyenza iimpawu zayo ezibonakalayo zibonise i-anisotropy.

Iipropati kunye nokusetyenziswa kwe-carbon fiber

Ifayibha yeCarbon inokohlulwa ibe yifilament, i-fiber staple, kunye ne-staple fiber. Iimpawu zomatshini zihlulwe zibe luhlobo oluqhelekileyo kunye nodidi oluphezulu. Amandla e-carbon fiber ngokubanzi yi-1000 MPa, imodyuli malunga ne-10OGPa. I-high-performance carbon fiber ihlukaniswe ngohlobo lwamandla aphezulu (amandla e-2000MPa, i-modulus 250GPa) kunye nemodeli ephezulu (imodyuli ngaphezu kwe-300GPa). Amandla amakhulu kune-4000MPa ikwabizwa ngokuba luhlobo lwamandla aphezulu; Abo banemodyuli enkulu kune-450GPa babizwa ngokuba yimodeli ephezulu kakhulu. Ngophuhliso lweshishini le-aerospace kunye ne-aviation, amandla aphezulu kunye ne-carbon fiber elongation ephezulu ibonakala, kwaye ubude bayo bungaphezulu kwe-2%. Isixa esikhulu yi-polypropylene eye-PAN-based carbon fiber. I-Carbon fiber inamandla aphezulu e-axial kunye ne-modulus, akukho ngqungquthela, ukumelana nokudinwa okulungileyo, ukushisa okuthe ngqo kunye nokuhamba kombane phakathi kwe-non-metal kunye nentsimbi, i-coefficient encinci yokwandisa i-thermal, ukuxhathisa okulungileyo kwe-corrosion, ubuninzi be-fiber ephantsi, kunye nokuhanjiswa okulungileyo kwe-X-ray. Nangona kunjalo, ukuchasana kwempembelelo yayo kubi kwaye kulula ukuyonakalisa, i-oxidation iyenzeka phantsi kwesenzo se-asidi eqinile, kunye ne-carbonization yensimbi, i-carburization, kunye ne-electrochemical corrosion yenzeke xa idibene nesinyithi. Ngenxa yoko, i-carbon fiber kufuneka iphathwe phezulu ngaphambi kokusetyenziswa.