I. Thermal wear and cobalt kuchotsa PDC
Mu ndondomeko mkulu kuthamanga sintering wa PDC, cobalt amachita monga chothandizira kulimbikitsa kuphatikiza mwachindunji diamondi ndi diamondi, ndi kupanga diamondi wosanjikiza ndi tungsten carbide masanjidwewo kukhala lonse, chifukwa PDC kudula mano oyenera oilfield pobowola geological ndi kulimba mkulu ndi kukana kwambiri kuvala,
Kukana kutentha kwa diamondi ndikochepa. Pansi pa mphamvu ya mumlengalenga, pamwamba pa diamondi imatha kusintha kutentha pafupifupi 900 ℃ kapena kupitilira apo. Mukagwiritsidwa ntchito, ma PDC achikhalidwe amatha kutsika pafupifupi 750 ℃. Pobowola pamiyala yolimba komanso yonyezimira, ma PDC amatha kufika kutentha kumeneku mosavuta chifukwa cha kutentha kwamphamvu, ndipo kutentha kwanthawi yomweyo (ie, kutentha komwe kumakhala pamlingo wa microscopic) kumatha kukhala kopitilira muyeso, kupitilira momwe amasungunuka a cobalt (1495 ° C).
Poyerekeza ndi diamondi yoyera, chifukwa cha kukhalapo kwa cobalt, diamondi imasandulika kukhala graphite pa kutentha kochepa. Chotsatira chake, kuvala kwa diamondi kumachitika chifukwa cha graphitization yobwera chifukwa cha kutentha komweko. Kuphatikiza apo, kuchuluka kwa matenthedwe a cobalt ndikokwera kwambiri kuposa diamondi, kotero pakuwotcha, kulumikizana pakati pa njere za diamondi kumatha kusokonezedwa ndi kukulitsa kwa cobalt.
Mu 1983, ofufuza awiri adachita chithandizo chochotsa diamondi pamwamba pa zigawo zokhazikika za diamondi za PDC, ndikupititsa patsogolo magwiridwe antchito a mano a PDC. Komabe, kutulukira kumeneku sikunalandire chisamaliro choyenera. Sizinatheke mpaka pambuyo pa 2000 kuti, ndikumvetsetsa mozama za zigawo za diamondi za PDC, ogulitsa kubowola adayamba kugwiritsa ntchito ukadaulo uwu ku mano a PDC omwe amagwiritsidwa ntchito pobowola miyala. Mano opangidwa ndi njirayi ndi oyenera kupanga mapangidwe otupa kwambiri okhala ndi makina otenthetsera otenthetsera ndipo nthawi zambiri amatchedwa "de-cobalted" mano.
Zomwe zimatchedwa "de-cobalt" zimapangidwira mwachikhalidwe kupanga PDC, ndiyeno pamwamba pa diamondi wosanjikiza wake amamizidwa mu asidi amphamvu kuchotsa gawo la cobalt kupyolera mu ndondomeko ya asidi etching. Kuzama kwa kuchotsa cobalt kumatha kufika pafupifupi ma microns 200.
Mayeso ovala zolemetsa anachitidwa pa mano awiri ofanana a PDC (amodzi mwa iwo anali atachitidwapo chithandizo chochotsa cobalt pamtunda wa diamondi). Pambuyo podula 5000m ya granite, zinapezeka kuti kuvala kwa PDC yopanda cobalt-cobalt kunayamba kuwonjezeka kwambiri. Mosiyana ndi izi, PDC yochotsedwa ndi cobalt idasunga liwiro lokhazikika ndikudula miyala pafupifupi 15000m.
2. Njira yodziwira PDC
Pali mitundu iwiri ya njira zodziwira mano a PDC, kuyesa kowononga komanso kuyesa kosawononga.
1. Kuyesa kowononga
Mayeserowa amapangidwa kuti azifanizira mikhalidwe ya kutsika kwapansi momwe angathere kuti awone momwe kudula mano kumagwirira ntchito mumikhalidwe yotere. Mitundu iwiri ikuluikulu ya kuyesa kowononga ndi kuyesa kukana kuvala komanso kuyesa kukana mphamvu.
(1) Valani kukana kuyesa
Mitundu itatu ya zida zimagwiritsidwa ntchito poyesa kuyesa kwa PDC kuvala:
A. Vertical lathe (VTL)
Pakuyesa, konzani kaye PDC ku lathe ya VTL ndikuyika chitsanzo cha mwala (nthawi zambiri granite) pafupi ndi PDC bit. Kenaka tembenuzani chitsanzo cha thanthwe mozungulira nsonga ya lathe pa liwiro linalake. Chidutswa cha PDC chimadula mumwala ndi kuya kwake. Mukamagwiritsa ntchito granite poyesa, kuzama kumeneku kumakhala kosakwana 1 mm. Mayesowa akhoza kukhala owuma kapena onyowa. Mu "kuyesa kwa VTL kowuma," pamene PDC imadula thanthwe, palibe kuziziritsa komwe kumayikidwa; kutentha konse komwe kumapangidwa kumalowa mu PDC, ndikufulumizitsa njira ya graphitization ya diamondi. Njira yoyeserayi imakhala ndi zotsatira zabwino kwambiri powunika ma bits a PDC pansi pamikhalidwe yomwe imafunikira kuthamanga kwambiri pobowola kapena kuthamanga kwambiri.
"Mayeso a VTL onyowa" amazindikira moyo wa PDC pansi pa kutentha pang'ono poziziritsa mano a PDC ndi madzi kapena mpweya poyesa. Chifukwa chake, gwero lalikulu la mayesowa ndikugaya kwamwala m'malo motenthetsa.
B, lathe yopingasa
Mayesowa amachitidwanso ndi granite, ndipo mfundo ya mayesoyo ndi yofanana ndi VTL. Nthawi yoyesera ndi mphindi zochepa chabe, ndipo kugwedezeka kwa kutentha pakati pa granite ndi mano a PDC ndi ochepa kwambiri.
Mayeso a granite omwe amagwiritsidwa ntchito ndi ogulitsa zida za PDC amasiyana. Mwachitsanzo, magawo oyesera omwe amagwiritsidwa ntchito ndi Synthetic Corporation ndi DI Company ku United States sali ofanana ndendende, koma amagwiritsa ntchito zida za granite zomwezo poyesa, mwala woyaka mpaka wapakatikati wa polycrystalline igneous rock wokhala ndi porosity pang'ono komanso mphamvu yopondereza ya 190MPa.
C. Chida choyezera chiŵerengero cha abrasion
Pansi pamikhalidwe yomwe idanenedwa, wosanjikiza wa diamondi wa PDC umagwiritsidwa ntchito chepetsa gudumu lopera la silicon carbide, ndipo kuchuluka kwa mavalidwe a gudumu logaya ndi mavalidwe a PDC amatengedwa ngati index yovala ya PDC, yomwe imatchedwa chiŵerengero cha kuvala.
(2) Kuyesa kukana kwamphamvu
Njira yoyezera kukhudzidwa imaphatikizapo kuyika mano a PDC pakona ya madigiri 15-25 ndikugwetsa chinthu kuchokera pamtunda wina kuti chimenye gawo la diamondi pamano a PDC molunjika. Kulemera ndi kutalika kwa chinthu chakugwa kumawonetsa mphamvu yamagetsi yomwe dzino loyesedwa limakumana nalo, lomwe limatha kuwonjezereka pang'onopang'ono mpaka 100 joules. Dzino lililonse limatha kukhudzidwa 3-7 mpaka silingayesedwenso. Nthawi zambiri, zitsanzo zosachepera 10 za mtundu uliwonse wa dzino zimayesedwa pamlingo uliwonse wa mphamvu. Popeza pali kusiyanasiyana kwa kukana kwa mano kuti akhudzidwe, zotsatira zoyesa pamlingo uliwonse wa mphamvu ndi gawo lapakati la diamondi spalling pambuyo pa kukhudza dzino lililonse.
2. Kuyesa kosawononga
Njira yoyesera yomwe imagwiritsidwa ntchito kwambiri yosawononga (kupatula kuyang'ana kowoneka ndi maso) ndi ultrasonic scanning (Cscan).
Ukadaulo wosanthula C ukhoza kuzindikira zolakwika zazing'ono ndikuzindikira malo ndi kukula kwa zolakwika. Mukamayesa izi, choyamba ikani dzino la PDC mu thanki yamadzi, ndiyeno jambulani ndi kafukufuku wa akupanga;
Nkhaniyi idasindikizidwanso kuchokera ku “International Metalworking Network“
Nthawi yotumiza: Mar-21-2025
