I. Lalacewar zafi da cire sinadarin cobalt na PDC
A cikin tsarin haɗakar matsi mai ƙarfi na PDC, cobalt yana aiki azaman mai haɓaka haɗin kai tsaye na lu'u-lu'u da lu'u-lu'u, kuma yana sa layin lu'u-lu'u da matrix na tungsten carbide su zama cikakke, wanda ke haifar da haƙoran yanke PDC waɗanda suka dace da haƙoran ƙasa na mai tare da babban tauri da juriya mai kyau.
Juriyar zafin lu'u-lu'u tana da iyaka sosai. A ƙarƙashin matsin lamba na yanayi, saman lu'u-lu'u na iya canzawa a yanayin zafi kusan 900℃ ko sama da haka. A lokacin amfani, PDCs na gargajiya suna lalacewa a kusan 750℃. Lokacin haƙa ta cikin layukan duwatsu masu tauri da masu lalata, PDCs na iya isa wannan zafin cikin sauƙi saboda zafi mai ƙarfi, kuma zafin jiki nan take (watau, zafin jiki na gida a matakin ƙananan) na iya zama mafi girma, wanda ya wuce wurin narkewar cobalt (1495°C).
Idan aka kwatanta da tsantsar lu'u-lu'u, saboda kasancewar cobalt, lu'u-lu'u yana canzawa zuwa graphite a ƙananan yanayin zafi. Sakamakon haka, lalacewa akan lu'u-lu'u yana faruwa ne sakamakon graphitization wanda ya samo asali daga zafi mai ƙarfi na gida. Bugu da ƙari, ƙimar faɗaɗa zafi na cobalt ya fi na lu'u-lu'u girma, don haka yayin dumama, haɗin da ke tsakanin ƙwayoyin lu'u-lu'u na iya lalacewa ta hanyar faɗaɗa cobalt.
A shekarar 1983, masu bincike biyu sun yi maganin cire lu'u-lu'u a saman layukan lu'u-lu'u na PDC na yau da kullun, wanda hakan ya inganta aikin haƙoran PDC sosai. Duk da haka, wannan ƙirƙira ba ta sami kulawar da ta cancanta ba. Sai bayan shekara ta 2000, tare da fahimtar layukan lu'u-lu'u na PDC, masu samar da haƙoran sun fara amfani da wannan fasaha ga haƙoran PDC da ake amfani da su wajen haƙo duwatsu. Haƙoran da aka yi wa magani da wannan hanyar sun dace da yanayin da ke da ƙarfi sosai tare da lalacewar injina mai zafi kuma ana kiransu da haƙoran "marasa amfani".
Ana yin abin da ake kira "de-cobalt" ta hanyar gargajiya don yin PDC, sannan a nutsar da saman layin lu'u-lu'u a cikin acid mai ƙarfi don cire matakin cobalt ta hanyar tsarin etching acid. Zurfin cire cobalt zai iya kaiwa kimanin microns 200.
An gudanar da gwajin lalacewa mai tsanani a kan haƙoran PDC guda biyu iri ɗaya (ɗaya daga cikinsu an yi masa maganin cire cobalt a saman saman lu'u-lu'u). Bayan an yanke dutse mai tsawon mita 5000, an gano cewa yawan lalacewa na PDC wanda ba a cire cobalt ba ya fara ƙaruwa sosai. Sabanin haka, PDC da aka cire cobalt ya ci gaba da samun saurin yankewa mai kyau yayin da yake yanke kusan mita 15000 na dutse.
2. Hanyar gano PDC
Akwai hanyoyi guda biyu na gano haƙoran PDC, wato gwajin lalata da gwajin da ba ya lalata haƙoran.
1. Gwaji mai lalata
An yi nufin waɗannan gwaje-gwajen ne don kwaikwayon yanayin ramin da ke ƙasa gwargwadon iyawa don tantance aikin yanke haƙora a ƙarƙashin irin waɗannan yanayi. Manyan nau'ikan gwaje-gwaje guda biyu na lalata su ne gwaje-gwajen juriyar lalacewa da gwaje-gwajen juriyar tasiri.
(1) Gwajin juriyar sa
Ana amfani da nau'ikan kayan aiki guda uku don yin gwaje-gwajen juriya ga lalacewa ta PDC:
A. Lathe mai tsayi (VTL)
A lokacin gwajin, da farko a gyara ma'aunin PDC zuwa ma'aunin VTL sannan a sanya samfurin dutse (yawanci granite) kusa da ma'aunin PDC. Sannan a juya samfurin dutsen a kusa da ma'aunin a wani gudu. Ma'aunin PDC yana yanke samfurin dutsen tare da wani zurfin musamman. Lokacin amfani da dutse don gwaji, wannan zurfin yankewa gabaɗaya ƙasa da mm 1. Wannan gwajin na iya zama ko dai bushe ko rigar. A cikin "gwajin VTL busasshe," lokacin da ma'aunin PDC ya yanke ta cikin dutsen, ba a sanyaya ba; duk zafin gogayya da aka samar yana shiga PDC, yana hanzarta tsarin zane-zane na lu'u-lu'u. Wannan hanyar gwaji tana ba da sakamako mai kyau lokacin kimanta ma'aunin PDC a ƙarƙashin yanayin da ke buƙatar matsin lamba mai yawa ko saurin juyawa mai yawa.
Gwajin "jika VTL" yana gano tsawon rayuwar PDC a ƙarƙashin yanayin dumama mai matsakaici ta hanyar sanyaya haƙoran PDC da ruwa ko iska yayin gwaji. Saboda haka, babban tushen lalacewa na wannan gwajin shine niƙa samfurin dutsen maimakon abin dumama.
B, injin lathe a kwance
Ana kuma yin wannan gwajin da granite, kuma ƙa'idar gwajin iri ɗaya ce da VTL. Lokacin gwajin 'yan mintuna ne kawai, kuma girgizar zafi tsakanin haƙoran granite da PDC tana da iyaka sosai.
Sigogin gwajin granite da masu samar da kayan aikin PDC ke amfani da su za su bambanta. Misali, sigogin gwajin da Kamfanin Synthetic Corporation da Kamfanin DI ke amfani da su a Amurka ba iri ɗaya ba ne, amma suna amfani da kayan granite iri ɗaya don gwaje-gwajensu, wani dutse mai kauri zuwa matsakaici mai ƙarfi wanda ke da ƙarancin porosity da ƙarfin matsi na 190MPa.
C. Kayan aikin auna rabon abrasion
A ƙarƙashin sharuɗɗan da aka ƙayyade, ana amfani da layin lu'u-lu'u na PDC don yanke ƙafafun niƙa na silicon carbide, kuma ana ɗaukar rabon ƙimar lalacewa na ƙafafun niƙa da ƙimar lalacewa na PDC azaman ma'aunin lalacewa na PDC, wanda ake kira rabon lalacewa.
(2) Gwajin juriyar tasiri
Hanyar gwajin tasiri ta ƙunshi sanya haƙoran PDC a kusurwar digiri 15-25 sannan a sauke wani abu daga wani tsayi don ya buga layin lu'u-lu'u a kan haƙoran PDC a tsaye. Nauyi da tsayin abin da ke faɗuwa suna nuna matakin tasirin kuzarin da haƙorin gwajin ya fuskanta, wanda a hankali zai iya ƙaruwa har zuwa joules 100. Kowane haƙori za a iya shafa shi sau 3-7 har sai ba za a iya gwada shi ba. Gabaɗaya, ana gwada aƙalla samfura 10 na kowane nau'in haƙori a kowane matakin kuzari. Tunda akwai iyaka a cikin juriyar haƙora ga tasiri, sakamakon gwajin a kowane matakin kuzari shine matsakaicin yanki na zubar lu'u-lu'u bayan tasiri ga kowane haƙori.
2. Gwaji mara lalatawa
Hanya mafi amfani da ake amfani da ita wajen gwajin da ba ya lalata jiki (banda duba gani da na'urar duba ƙwayoyin cuta) ita ce duban na'urar daukar hoton ultrasonic (Cscan).
Fasahar daukar hoton C na iya gano ƙananan lahani da kuma tantance wurin da lahani ke faruwa da kuma girmansu. Lokacin yin wannan gwajin, da farko sanya haƙorin PDC a cikin tankin ruwa, sannan a yi scanning da na'urar bincike ta ultrasonic;
An sake buga wannan labarin daga "Cibiyar Aikin Karfe ta Duniya"
Lokacin Saƙo: Maris-21-2025
