Kuwonongeka kwa kutentha ndi kuchotsa cobalt ya PDC

I. Kuwonongeka kwa kutentha ndi kuchotsa cobalt ya PDC

Mu ndondomeko ya PDC yopopera mphamvu kwambiri, cobalt imagwira ntchito ngati chothandizira kulimbikitsa kuphatikiza mwachindunji kwa diamondi ndi diamondi, ndikupangitsa kuti diamondi ndi tungsten carbide matrix zikhale zonse, zomwe zimapangitsa kuti mano odulira a PDC akhale oyenera kuboola malo osungira mafuta ndi kulimba kwambiri komanso kukana kutopa kwambiri,

Kukana kutentha kwa diamondi kumakhala kochepa. Pakapanikizika mumlengalenga, pamwamba pa diamondi pamatha kusintha kutentha pafupifupi 900℃ kapena kupitirira apo. Pakagwiritsidwa ntchito, ma PDC achikhalidwe amatha kuwonongeka pafupifupi 750℃. Pobowola miyala yolimba komanso yolimba, ma PDC amatha kufika kutentha kumeneku mosavuta chifukwa cha kutentha kokangana, ndipo kutentha komweko (monga kutentha komwe kumakhalapo pamlingo wa microscopic) kumatha kukhala kwakukulu kwambiri, kupitirira kwambiri kusungunuka kwa cobalt (1495°C).

Poyerekeza ndi diamondi yeniyeni, chifukwa cha kukhalapo kwa cobalt, diamondi imasanduka graphite pa kutentha kochepa. Chifukwa cha zimenezi, diamondi imawonongeka chifukwa cha graphitization yomwe imachitika chifukwa cha kutentha komwe kumachitika m'deralo. Kuphatikiza apo, coefficient ya kutentha kwa cobalt ndi yayikulu kwambiri kuposa ya diamondi, kotero panthawi yotenthetsera, mgwirizano pakati pa tinthu ta diamondi ukhoza kusokonekera chifukwa cha kukula kwa cobalt.

Mu 1983, ofufuza awiri adachita chithandizo chochotsa diamondi pamwamba pa zigawo za diamondi za PDC, zomwe zidapangitsa kuti mano a PDC azigwira bwino ntchito. Komabe, chipangizochi sichinalandire chisamaliro chomwe chimayenera kugwira ntchito. Pambuyo pa chaka cha 2000, ogulitsa mabowo anayamba kugwiritsa ntchito ukadaulo uwu pa mano a PDC omwe amagwiritsidwa ntchito pobowola miyala. Mano okonzedwa ndi njira iyi ndi oyenera mapangidwe okhwima kwambiri okhala ndi kutentha kwambiri ndipo nthawi zambiri amatchedwa mano "ochotsedwa cobalted".

Chomwe chimatchedwa "de-cobalt" chimapangidwa mwanjira yachikhalidwe popanga PDC, kenako pamwamba pa diamondi yake imamizidwa mu asidi wamphamvu kuti ichotse gawo la cobalt kudzera mu njira yochotsera asidi. Kuzama kwa kuchotsa cobalt kumatha kufika pafupifupi ma microns 200.

Kuyezetsa kwakukulu kwa mano odulidwa kunachitika pa mano awiri ofanana a PDC (limodzi mwa iwo linachotsedwa cobalt pamwamba pa diamondi). Pambuyo podula granite wa mamita 5000, zinapezeka kuti kuchuluka kwa kuwonongeka kwa PDC yomwe sinachotsedwe cobalt kunayamba kukwera kwambiri. Mosiyana ndi zimenezi, PDC yomwe inachotsedwa cobalt inasunga liwiro lodula lokhazikika pamene inadula miyala ya mamita pafupifupi 15000.

2. Njira yodziwira PDC

Pali njira ziwiri zodziwira mano a PDC, zomwe ndi kuyeza kowononga ndi kuyesa kosawononga.

1. Kuyesa kowononga

Mayeso awa cholinga chake ndi kutsanzira momwe mano amagwirira ntchito m'mabowo momwe angathere kuti aone momwe kudula mano kumagwirira ntchito pazochitika zotere. Mitundu iwiri ikuluikulu ya mayeso owononga ndi mayeso oletsa kuvala ndi mayeso oletsa kukhudzidwa.

(1) Mayeso oletsa kuvala

Mitundu itatu ya zida zimagwiritsidwa ntchito poyesa kukana kuvala kwa PDC:

A. Chogwirira choyimirira (VTL)

Pa nthawi yoyesera, choyamba konzani PDC bit ku VTL lathe ndikuyika chitsanzo cha miyala (nthawi zambiri granite) pafupi ndi PDC bit. Kenako zungulirani chitsanzo cha miyala mozungulira mzere wa lathe pa liwiro linalake. PDC bit imadula mu chitsanzo cha miyala ndi kuya kwake. Mukagwiritsa ntchito granite poyesa, kuya kodulira kumeneku nthawi zambiri kumakhala kochepera 1 mm. Kuyesaku kungakhale kouma kapena konyowa. Mu "kuyesa kwa VTL kouma," pamene PDC bit imadula mumwala, palibe kuzizira komwe kumachitika; kutentha konse komwe kumachitika kumalowa mu PDC, zomwe zimathandizira njira yojambulira diamondi. Njira yoyeserayi imapereka zotsatira zabwino kwambiri poyesa ma PDC bits pansi pa mikhalidwe yomwe imafuna kupopera kwakukulu kapena liwiro lalikulu lozungulira.

"Mayeso a VTL onyowa" amazindikira moyo wa PDC pansi pa kutentha pang'ono mwa kuziziritsa mano a PDC ndi madzi kapena mpweya panthawi yoyesa. Chifukwa chake, gwero lalikulu la kutopa kwa mayesowa ndi kupukutira chitsanzo cha miyala osati kutentha.

B, lathe yopingasa

Kuyesaku kumachitikanso ndi granite, ndipo mfundo ya mayesowa ndi yofanana ndi VTL. Nthawi yoyesera ndi mphindi zochepa chabe, ndipo kutentha pakati pa granite ndi mano a PDC ndi kochepa kwambiri.

Ma parameter oyesera granite omwe amagwiritsidwa ntchito ndi ogulitsa zida za PDC amasiyana. Mwachitsanzo, ma parameter oyesera omwe amagwiritsidwa ntchito ndi Synthetic Corporation ndi DI Company ku United States si ofanana kwenikweni, koma amagwiritsa ntchito granite yomweyi poyesa kwawo, mwala wouma mpaka wapakati wokhala ndi ma polycrystalline igneous wokhala ndi ma porosity ochepa komanso mphamvu yokakamiza ya 190MPa.

C. Chida choyezera kuchuluka kwa kusweka kwa khungu

Pansi pa mikhalidwe yomwe yatchulidwa, diamondi wosanjikiza wa PDC umagwiritsidwa ntchito kudula gudumu lopukusira la silicon carbide, ndipo chiŵerengero cha kuchuluka kwa kusweka kwa gudumu lopukusira ndi kuchuluka kwa kusweka kwa PDC chimatengedwa ngati chizindikiro cha kusweka kwa PDC, chomwe chimatchedwa chiŵerengero cha kusweka.

(2) Mayeso oletsa kukhudzidwa ndi mphamvu

Njira yoyesera kukhudzidwa imaphatikizapo kuyika mano a PDC pa ngodya ya madigiri 15-25 kenako kugwetsa chinthu kuchokera kutalika kwina kuti chigunde diamondi pa mano a PDC molunjika. Kulemera ndi kutalika kwa chinthu chogwacho kumasonyeza mulingo wa mphamvu ya kukhudzidwa komwe kumapezeka ndi dzino loyesera, lomwe pang'onopang'ono lingakwere mpaka ma joules 100. Dzino lililonse likhoza kukhudzidwa nthawi 3-7 mpaka silingathe kuyesedwanso. Nthawi zambiri, zitsanzo zosachepera 10 za mtundu uliwonse wa dzino zimayesedwa pa mulingo uliwonse wa mphamvu. Popeza pali kusiyana kwa kukana kwa mano ku kukhudzidwa, zotsatira za mayeso pa mulingo uliwonse wa mphamvu ndi dera lapakati la kugwedezeka kwa diamondi pambuyo pa kukhudzidwa kwa dzino lililonse.

2. Kuyesa kosawononga

Njira yoyesera yosawononga yomwe imagwiritsidwa ntchito kwambiri (kupatula kuyang'ana ndi maso ndi ma microscopic) ndi ultrasound scanning (Cscan).

Ukadaulo wa C scanning ukhoza kuzindikira zolakwika zazing'ono ndikupeza malo ndi kukula kwa zolakwikazo. Mukachita mayesowa, choyamba ikani dzino la PDC mu thanki yamadzi, kenako sikani ndi ultrasound probe;

Nkhaniyi yasindikizidwanso kuchokera ku “Netiweki Yapadziko Lonse Yogwirira Ntchito Zachitsulo“