Ukusetyenzwa kwegrafu kunokuba lishishini elikhohlisayo, ngoko ukubeka imiba ethile kuqala kubalulekile kwimveliso kunye nenzuzo.
Inyaniso ibonise ukuba i-graphite inzima ukwenza umatshini, ngakumbi kwii-electrodes ze-EDM ezifuna ukuchaneka okugqwesileyo kunye nokuhambelana kwesakhiwo.Nazi iingongoma ezintlanu ezibalulekileyo ekufuneka uzikhumbule xa usebenzisa igraphite:
Amabakala egraphite abonakala kunzima ukuwahlula, kodwa ngalinye lineempawu ezikhethekileyo zomzimba kunye nokusebenza.Amabakala e-graphite ahlula kwiindidi ezintandathu ngokwemilinganiselo ye-particle, kodwa kuphela iindidi ezintathu ezincinci (ubungakanani be-particle ye-microns eyi-10 okanye ngaphantsi) zihlala zisetyenziswa kwi-EDM yanamhlanje.Irenki kuhlelo luphawu lwezicelo ezinokubakho kunye nokusebenza.
Ngokutsho kwenqaku likaDoug Garda (uToyo Tanso, owabhalela udade wethu upapasho "i-MoldMaking Technology" ngelo xesha, kodwa ngoku yi-SGL Carbon), amabanga anesayizi ye-particle ye-8 ukuya kwi-10 microns asetyenziselwa ukugoba.Ukugqitywa okuncinci kunye neenkcukacha zezicelo zisebenzisa amabakala angama-5 ukuya kwi-8 ubukhulu besuntswana le-micron.Ii-electrodes ezenziwe kula mabanga zihlala zisetyenziselwa ukwenza ukubumba kunye ne-die-casting molds, okanye umgubo ongenzima kakhulu kunye ne-sintered metal applications.
Uyilo lweenkcukacha ezintle kunye nezincinci, iimpawu ezinzima ngakumbi zifaneleke ngakumbi ubungakanani bamasuntswana ukusuka kwi-3 ukuya kwi-5 microns.Ukusetyenziswa kwe-Electrode kolu luhlu kubandakanya ukusika ucingo kunye ne-aerospace.
Ii-electrodes ezichanekileyo ezichanekileyo zisebenzisa amabakala egraphite kunye nobukhulu besuntswana le-1 ukuya kwi-3 microns zisoloko zifuneka kwi-aerospace ekhethekileyo yesinyithi kunye ne-carbide izicelo.
Xa ubhala inqaku le-MMT, uJerry Mercer we-Poco Materials uchonge ubungakanani bamasuntswana, amandla okugoba, kunye nobulukhuni be-Shore njengezona zigqibo ezithathu eziphambili zokusebenza ngexesha lokusetyenzwa kwe-electrode.Nangona kunjalo, i-microstructure yegraphite idla ngokuba yinto ethintelayo ekusebenzeni kwe-electrode ngexesha lokugqibela lokusebenza kwe-EDM.
Kwelinye inqaku le-MMT, uMercer wathi amandla okugoba kufuneka abe phezulu kune-13,000 psi ukuqinisekisa ukuba igraphite inokucutshungulwa ibe yiimbambo ezinzulu nezibhityileyo ngaphandle kokuqhekeka.Inkqubo yokwenziwa kwee-electrode zegraphite inde kwaye inokufuna iinkcukacha ezicacileyo, ezinzima kumatshini iimpawu, ngoko ke ukuqinisekisa ukuqina okunje kunceda ukunciphisa iindleko.
Ubunzima bonxweme bulinganisa ukusebenza kwamabakala egraphite.I-Mercer ilumkisa ukuba amabakala egraphite athambileyo kakhulu angavala izixhobo zokubeka izixhobo, acothise inkqubo yomatshini okanye agcwalise imingxuma ngothuli, ngaloo ndlela abeke uxinzelelo kwiindonga zemingxuma.Kule meko, ukunciphisa ukutya kunye nesantya kunokuthintela iimpazamo, kodwa kuya kwandisa ixesha lokucubungula.Ngexesha lokucubungula, i-graphite enzima, encinci-grained inokubangela ukuba izinto ezisekupheleni komngxuma ziphuke.Ezi zixhobo zinokuthi zibe zibi kakhulu kwisixhobo, ezikhokelela ekunxibeni, ezichaphazela ingqibelelo yobubanzi bomngxuma kunye nokwandisa iindleko zomsebenzi.Ngokubanzi, ukunqanda ukuphambuka kumaxabiso obunzima obuphezulu, kuyafuneka ukuba kuncitshiswe ukutya okusetyenzwayo kunye nesantya sendawo nganye ngobulukhuni beNxweme obungaphezulu kwama-80 nge-1%.
Ngenxa yendlela i-EDM eyenza ngayo umfanekiso wesibuko se-electrode kwinxalenye ecutshungulwayo, uMercer uphinde wathi i-microstructure ehlanganiswe ngokuqinileyo, i-uniform microstructure iyimfuneko kwi-electrode yegraphite.Imida yamasuntswana angalinganiyo yandisa i-porosity, ngaloo ndlela inyusa ukukhukuliseka kwamasuntswana kunye nokukhawulezisa ukungaphumeleli kwe-electrode.Ngexesha lenkqubo yokuqala ye-electrode machining, i-microstructure engalinganiyo inokukhokelela ekugqityweni komphezulu ongalinganiyo-le ngxaki inzulu ngakumbi kumaziko omatshini anesantya esiphezulu.Iindawo eziqinileyo kwigraphite nazo zinokubangela ukuba isixhobo sijike, sibangele ukuba i-electrode yokugqibela ingabikho kwinkcazo.Oku kuphambuka kunokuba mncinci ngokwaneleyo ukuba umngxuma oblique ubonakale ngqo kwindawo yokungena.
Kukho oomatshini abakhethekileyo bokulungisa igraphite.Nangona aba matshini beza kuyikhawulezisa kakhulu imveliso, asingabo kuphela oomatshini abanokusebenzisa abavelisi.Ukongeza ekulawuleni uthuli (okuchazwe kamva kwinqaku), amanqaku e-MMS adlulileyo aphinde achaza iingenelo zoomatshini abanee-spindles ezikhawulezayo kunye nolawulo olunesantya esiphezulu sokwenza i-graphite.Ngokufanelekileyo, ulawulo olukhawulezayo lufanele lube neempawu ezijonge phambili, kwaye abasebenzisi kufuneka basebenzise isoftware yokwenza indlela yesixhobo.
Xa efakela i-electrode yegraphite—oko kukuthi, ukuzalisa imingxuma yegraphite microstructure ngamasuntswana alingana nemicron—uGarda ucebisa ukuba kusetyenziswe ubhedu kuba luyakwazi ukucwangcisa ngokuzinzileyo iialloys ezikhethekileyo zobhedu nenickel, ezifana nezo zisetyenziswa kwi-aerospace application.Amabakala egraphite enziwe ngobhedu avelisa iziphumo ezigqwesileyo kunamabanga angafakwanga odidi olufanayo.Basenokuthi bafezekise inkqubo ezinzileyo xa besebenza phantsi kweemeko ezimbi ezifana nokugungxulwa kakubi okanye abaqhubi abangenamava.
Ngokutsho kwenqaku lesithathu le-Mercer, nangona i-graphite yokwenziwa-uhlobo olusetyenziselwa ukwenza i-EDM electrode-i-inert ye-biologically inert kwaye ngoko ke ekuqaleni ayinabungozi kubantu kunezinye izinto, ukungena komoya okungafanelekanga kusenokubangela iingxaki.I-Synthetic graphite i-conductive, enokubangela iingxaki kwisixhobo, esinokuthi sijikeleze ngokukhawuleza xa sidibana nemathiriyeli yangaphandle.Ukongezelela, i-graphite efakwe kwizinto ezifana nobhedu kunye ne-tungsten idinga ukunakekelwa okungaphezulu.
UMercer wachaza ukuba iliso lomntu alikwazi ukubona uthuli lwegraphite kwiindawo ezincinci kakhulu, kodwa lusenokubangela ukucaphuka, ukukrazula kunye nokubomvu.Ukudibana nothuli lunokuba lukhuni kwaye lucaphuke kancinci, kodwa akunakwenzeka ukuba lufunnwe.Umyinge wexesha elilinganiselweyo (i-TWA) isikhokelo sokuvezwa kothuli lwegraphite kwiiyure ze-8 yi-10 mg / m3, eyona nto igxininiseko ebonakalayo kwaye ayiyi kubonakala kwinkqubo yokuqokelela uthuli olusetyenziswayo.
Ukugqithiswa ngokugqithiseleyo kuthuli lwegraphite ixesha elide kunokubangela ukuba iinqununu zegraphite ezifakwe ngaphakathi zihlale kwimiphunga kunye ne-bronchi.Oku kunokukhokelela kwipneumoconiosis engapheliyo ebizwa ngokuba sisifo segraphite.I-Graphitization idla ngokunxulumene negraphite yendalo, kodwa kwiimeko ezinqabileyo inxulumene negraphite yokwenziwa.
Uthuli oluqokelelana kwindawo yokusebenzela luvutha kakhulu, kwaye (kwinqaku lesine) uMercer uthi unokugqabhuka phantsi kweemeko ezithile.Xa ukutshisa kuhlangana nokuxinana okwaneleyo kwamasuntswana amahle amisiwe emoyeni, umlilo wothuli kunye nokutshatyalaliswa kuya kwenzeka.Ukuba uthuli luhlakazwa kwisixa esikhulu okanye kwindawo evaliweyo, kunokwenzeka ukuba luqhume.Ukulawula naluphi na uhlobo lwento enobungozi (amafutha, ioksijini, ukuvutha, ukusasazwa okanye uthintelo) kunokunciphisa kakhulu ukudubula kothuli.Kwiimeko ezininzi, ishishini lijolise kumafutha ngokususa uthuli kumthombo ngokungena komoya, kodwa iivenkile kufuneka ziqwalasele zonke izinto ukuphumeza ukhuseleko oluphezulu.Izixhobo zokulawula uthuli nazo kufuneka zibe nemingxuma ekwaziyo ukuqhuma okanye inkqubo yokuthintela uqhushumbo, okanye zifakwe kwindawo engenawo umoya-mpilo.
I-Mercer ichonge iindlela ezimbini eziphambili zokulawula uthuli lwegraphite: iinkqubo zomoya ezikhawulezayo kunye nabaqokeleli bothuli-ezinokulungiswa okanye eziphathwayo ngokuxhomekeke kwisicelo-kunye neenkqubo ezimanzi ezizalisa indawo ejikeleze umsiki kunye nolwelo.
Iivenkile ezenza isixa esincinci sokusetyenzwa kwegraphite zinokusebenzisa isixhobo esiphathwayo esine-high-efficiency particulate air (HEPA) isihluzo esinokushukunyiswa phakathi koomatshini.Nangona kunjalo, iindibano zocweyo ezenza isixa esikhulu segraphite kufuneka zisebenzise inkqubo emiselweyo.Ubuncinci besantya somoya ukubamba uthuli ziinyawo ezingama-500 ngomzuzu, kwaye isantya kumbhobho siyanda ukuya kuthi ga kwiimitha ezingama-2000 ngesekhondi.
Iinkqubo ezimanzi zenza umngcipheko wolwelo "u-wicking" (ukufakwa) kwizinto ze-electrode ukukhupha uthuli.Ukungaphumeleli ukususa i-fluid ngaphambi kokubeka i-electrode kwi-EDM kunokubangela ukungcoliswa kweoli ye-dielectric.Abaqhubi kufuneka basebenzise izisombululo ezisekelwe emanzini kuba ezi zisombululo zincinci kakhulu ekufunxeni ioli kunezisombululo ezisekelwe kwioli.Ukomisa i-electrode ngaphambi kokusebenzisa i-EDM ngokuqhelekileyo kubandakanya ukubeka izinto kwi-oven convection malunga neyure kwiqondo lokushisa elincinane ngaphezu kwendawo yokuphuphuma kwesisombululo.Iqondo lokushisa akufanele lidlule ama-degrees angama-400, njengoko oku kuya kukhupha i-oxidize kwaye kugqwese izinto.Abaqhubi akufanele basebenzise umoya ocinezelweyo ukomisa i-electrode, kuba uxinzelelo lomoya luya kunyanzela kuphela ulwelo olunzulu kwisakhiwo se-electrode.
Isixhobo sePrinceton sinethemba lokwandisa iphothifoliyo yayo yemveliso, yandise impembelelo yayo kuNxweme oluseNtshona, kwaye ibe ngumthengisi onamandla ngakumbi.Ukuze kuphunyezwe ezi njongo zintathu ngexesha elinye, ukufumana enye ivenkile yomatshini yaba yeyona nto ilungileyo.
Isixhobo se-EDM socingo sijikeleza intambo ye-electrode ekhokelwa ngokuthe tye kwi-CNC elawulwa yi-E axis, inika i-workshop imvume yokusebenzela kunye nokuguquguquka ukuvelisa izixhobo ze-PCD ezinzima kunye nezichanekileyo.
Ixesha lokuposa: Sep-26-2021