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I-Polycrystalline diamond compact (PDC) yokusika

Idayimani yeyona nto inzima eyaziwayo. Olu lukhuni lunika iipropati eziphezulu zokusika nayiphi na into. I-PDC ibaluleke kakhulu ekumbeni, kuba idibanisa iidayimani ezincinci, ezingabizi kakhulu, ezenziwe ngabantu zibe ziinkulu ezinkulu, ezihlanganisiweyo zeekristali ezijolise ngokungacwangciswanga ezinokuthi zenziwe zibe ziimilo eziluncedo ezibizwa ngokuba ziitafile zedayimane. Iitafile zedayimani ziyinxalenye yomsiki onxibelelana nokwakheka. Ngaphandle kobulukhuni babo, iitafile zedayimane ze-PDC zinempawu ebalulekileyo yokusika i-cutter-bit cutters: Zisebenza ngokudibeneyo kunye ne-tungsten carbide materials ezinokuthi zidityaniswe (ziqhotyoshelwe) kwimizimba emincinci. Iidayimani, ngokwazo, aziyi kudibana kunye, kwaye azinako ukudityaniswa ngobhedu.

Idayimane Synthetic

Idayimani grit idla ngokusetyenziselwa ukuchaza iinkozo ezincinci (≈0.00004 in.) Zedayimane eyenziweyo esetyenziswa njengezinto eziphambili ekrwada ezisikiweyo ze-PDC cutters. Ngokwemichiza kunye neepropathi, idayimani eyenziwe ngumntu iyafana nedayimane yendalo. Ukwenza i-diamond grit kubandakanya inkqubo elula yemichiza: ikhabhoni eqhelekileyo ifudunyezwa phantsi koxinzelelo oluphezulu kakhulu kunye nobushushu. Ukuziqhelanisa, nangona kunjalo, ukwenza idayimane kukude kube lula.

Ikristale nganye yedayimane equlethwe kwidayimani grit zijolise ngokwahlukileyo. Oku kwenza ukuba umbandela womelele, ubukhali, kwaye, ngenxa yobulukhuni bedayimane, inxibe kakhulu. Ngapha koko, ulwakhiwo olungahleliwe olufunyenwe kwidayimani ebumbeneyo lwenza ngcono ukucheba kuneedayimane zendalo, kuba iidayimani zendalo ziikristale zetyhubhu eziqhekeka ngokulula kulungelelwaniso lwazo, imida yekristallini.

Idayimani grit ayizinzanga kumaqondo obushushu aphezulu kuneedayimane yendalo, nangona kunjalo. Ngenxa yokuba i-catalist yentsimbi ebanjiswe kulwakhiwo lwe-grit inezinga eliphezulu lokukhula kwe-thermal kune-diamond, ulwandiso lokwahlula lubeka i-diamond-to-diamond bond under shear kwaye, ukuba imithwalo iphezulu ngokwaneleyo, ibangela ukusilela. Ukuba iibhondi ziyasilela, iidayimani zilahleka ngokukhawuleza, ke i-PDC iphulukana nobunzima bayo kunye nobukhali kwaye ingasebenzi. Ukuthintela ukusilela okunjalo, i-PDC cutters kufuneka ipholile ngokwaneleyo ngexesha lokomba.

Iitafile zedayimani

Ukwenza itafile yedayimane, i-diamond grit ifakwe kwi-tungsten carbide kunye ne-metallic binder ukwenza i-diamond ecebile. Zimile okweqanda kwaye zinemilo efana nesonkana esisicaba, kwaye kufuneka zenziwe zangqindilili ngangokunokwenzeka, kuba ivolumu yedayimane yonyusa ubomi. Iitafile zedayimani ekumgangatho ophakamileyo zii-to2 ukuya kwi-4 mm, kwaye inkqubela phambili yetekhnoloji iya kwandisa ubukhulu betafile yedayimani. I-Tungsten carbide substrates ziqhelekile ukuba zi -0.5 in kwaye zineendlela ezifanayo ezinqamlezileyo kunye nobukhulu njengetafile yedayimani. Amacandelo amabini, itafile yedayimane kunye ne-substrate, zenza umsiki (Ikhiwane. 4).

Ukwenza i-PDC kwiimilo eziluncedo kubasiki kubandakanya ukubeka i-diamond grit, kunye ne-substrate yayo, kwisitya soxinzelelo kwaye emva koko sintering kubushushu obuphezulu noxinzelelo.

Abasiki be-PDC abanakuvunyelwa ukuba badlule kumaqondo obushushu ayi-1,382 ° F [750 ° C]. Ubushushu obugqithisileyo bivelisa ukunxiba okukhawulezayo, kuba umahluko wokwanda kwe-thermal phakathi kwe-binder kunye nedayimane ithambekele ekophuleni iikristali zegridi yedayimane kwitafile yedayimane. Amandla ebond phakathi kwetafile yedayimani kunye ne-tungsten carbide substrate nayo ibekwa emngciphekweni kukwanda okwahlukileyo kwe-thermal.


Ixesha Post: Apr-08-2021