1.4 Ukugaya okwesibili
Inhlama iyachotshozwa, igaywe futhi ihlungwe ibe yizinhlayiya ezingamashumi kuya kumakhulu ama-micrometer ngosayizi ngaphambi kokuba zixutshwe ngokulinganayo.Isetshenziswa njengento yokucindezela, ebizwa ngokuthi i-pressing powder.Izisetshenziswa zokugaya okwesibili ngokuvamile zisebenzisa isigayo se-roller esime mpo noma isigayo sebhola.
1.5 Ukwakha
Ngokungafani ne-extrusion evamile nokubunjwa,i-graphite yokucindezela isostatickwakhiwa kusetshenziswa ubuchwepheshe obubandayo be-isostatic pressing (Figure 2).Gcwalisa impushana yezinto ezingavuthiwe esikhunjeni serabha, bese uhlanganisa impushana ngokudlidliza kwe-electromagnetic vibration.Ngemuva kokuvalwa, vala izinhlayiya zempushana ukuze ukhiphe umoya phakathi kwazo.Yibeke esitsheni esinengcindezi ephezulu equkethe imidiya ewuketshezi efana namanzi noma uwoyela, uyicindezele ibe ngu-100-200MPa, bese uyicindezela ibe yicylindrical noma umkhiqizo ongunxande.
Ngokwesimiso sikaPascal, ingcindezi isetshenziswa esikhunjeni senjoloba ngokusebenzisa uketshezi olufana namanzi, futhi ukucindezela kuyalingana kuzo zonke izinkomba.Ngale ndlela, izinhlayiya ze-powder azihlosiwe ekugcwaliseni isiqondiso ekubunjweni, kodwa zicindezelwe ngendlela engavamile.Ngakho-ke, nakuba i-graphite iyi-anisotropic ezindaweni ze-crystallographic, jikelele, i-isostatic pressing graphite i-isotropic.Imikhiqizo eyakhiwe ayinayo nje kuphela imimo ye-cylindrical kanye ne-rectangular, kodwa futhi i-cylindrical kanye ne-crucible shapes.
Umshini wokubumba wokucindezela we-isostatic usetshenziswa kakhulu embonini ye-powder metallurgy.Ngenxa yesidingo sezimboni ezisezingeni eliphezulu ezifana ne-aerospace, imboni yenuzi, ama-alloys aqinile, ne-high-voltage electromagnetic, ukuthuthukiswa kobuchwepheshe bokucindezela kwe-isostatic kuyashesha kakhulu, futhi inamandla okwenza imishini yokucindezela ye-isostatic ebandayo ngesilinda esisebenzayo. Ububanzi bangaphakathi bungu-3000mm, ubude bungu-5000mm, kanye nengcindezi yokusebenza ephezulu engu-600MPa.Njengamanje, ukucaciswa okuphezulu kwemishini yokucindezela ye-isostatic ebandayo esetshenziswa embonini yekhabhoni yokukhiqiza i-isostatic pressing graphite ingu-Φ 2150mm × 4700mm, enengcindezi yokusebenza ephezulu engu-180MPa.
1.6 Ukubhaka
Phakathi nenqubo yokuthosa, ukusabela kwamakhemikhali okuyinkimbinkimbi kwenzeka phakathi kwe-aggregate ne-binder, okubangela ukuthi isibopho sibole futhi sikhulule inani elikhulu lezinto eziguquguqukayo, kuyilapho futhi senza ukusabela kwe-condensation.Esigabeni sokushisa esisezingeni eliphansi, umkhiqizo oluhlaza uyanda ngenxa yokushisa, futhi inqubo yokushisa elandelayo, ivolumu iyancipha ngenxa yokusabela kwe-condensation.
Uma umthamo womkhiqizo oluhlaza umkhulu, kuba nzima nakakhulu ukukhulula izinto ezishintshashintshayo, futhi ingaphezulu nengaphakathi lomkhiqizo oluhlaza kujwayele ukwehluka kwezinga lokushisa, ukunwetshwa kokushisa okungalingani kanye nokufinyela, okungase kuholele ekuqhekekeni komkhiqizo ongavuthiwe.
Ngenxa yesakhiwo sayo esihle, i-isostatic yokucindezela i-graphite idinga inqubo yokugazinga kancane kancane, futhi izinga lokushisa ngaphakathi kwesithando somlilo kufanele lifane kakhulu, ikakhulukazi ngesikhathi sezinga lokushisa lapho ama-asphalt volatiles ekhishwa ngokushesha.Inqubo yokushisa kufanele yenziwe ngokuqapha, ngezinga lokushisa elingadluli ku-1 ℃/h kanye nomehluko wokushisa ngaphakathi kwesithando somlilo ongaphansi kuka-20 ℃.Le nqubo ithatha cishe izinyanga ezingu-1-2.
1.7 Ukukhulelwa
Ngesikhathi sokugazinga, indaba eguquguqukayo yetiyela yamalahle iyakhishwa.Ama-pores amahle ashiywe emkhiqizweni ngesikhathi sokukhishwa kwegesi kanye nokunciphisa ivolumu, cishe wonke ama-pores avulekile.
Ukuze kuthuthukiswe ukuminyana kwevolumu, amandla emishini, ukusebenza kahle, ukuguquguquka kwe-thermal, kanye nokumelana namakhemikhali omkhiqizo, indlela yokufaka ingcindezi ingasetshenziswa, okubandakanya ukumilisa itiyela lamalahle ngaphakathi komkhiqizo ngokusebenzisa izimbotshana ezivulekile.
Umkhiqizo udinga ukushisisa kuqala, bese ukhishwa futhi ukhishwe ku-tank yokufaka.Khona-ke, i-asphalt ye-coal tar encibilikisiwe yengezwa ethangini lokukhulelwa futhi icindezelekile ukuze i-asphalt ye-ejenti ekhulelwe ingene ngaphakathi komkhiqizo.Imvamisa, i-isostatic pressing graphite ingena emijikelezweni eminingi yokuthoswa kwe-imregnation.
1.8 I-Graphitization
Shisisa umkhiqizo owenziwe nge-calcined ufike ku-3000 ℃, hlela i-lattice yama-athomu ekhabhoni ngendlela ehlelekile, bese uqedela ukuguqulwa kusuka ku-carbon kuya ku-graphite, okubizwa ngokuthi i-graphitization.
Izindlela ze-graphitization zihlanganisa indlela ye-Acheson, indlela yokuxhuma yochungechunge lwangaphakathi olushisayo, indlela yokungeniswa kwe-high-frequency induction, njll. Inqubo evamile ye-Acheson ithatha cishe izinyanga ezingu-1-1.5 ukuze imikhiqizo ilayishwe futhi ikhishwe esithandweni.Isithando somlilo ngasinye singaphatha amathani amaningana kuya kumathani amathani emikhiqizo ethosiwe.
Isikhathi sokuthumela: Sep-29-2023