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Ocheka miyala ya polycrystalline diamond (PDC)

Daimondi ndiye chinthu chovuta kwambiri kudziwika. Kuuma kumeneku kumakupatsirani zida zabwino zodulira china chilichonse. PDC ndiyofunikira kwambiri pobowola, chifukwa imagawa ma diamondi ang'onoang'ono, otchipa, opangidwa ndi mamankhwala kukhala miyala yayikulu kwambiri, yolumikizana ndi timibulu tomwe timapanga timitundu tomwe timatha kupanga matabwa a diamondi. Ma tebulo a diamondi ndi gawo la wodula omwe amalumikizana ndi mapangidwe. Kuphatikiza pakuuma kwawo, matebulo a diamondi a PDC ali ndi gawo lofunikira kwa odulira pobowola: Amalumikizana bwino ndi zida za tungsten carbide zomwe zimatha kulumikizidwa (zolumikizidwa) ndi matupi pang'ono. Ma diamondi, paokha, sangagwirizane, komanso sangathe kulumikizidwa ndi brazing.

Daimondi yopanga

Daimondi imagwiritsidwa ntchito pofotokoza mbewu zazing'ono (≈0.00004 mkati.) Za diamondi zopangira zomwe zimagwiritsidwa ntchito ngati chinthu chofunikira kwa odulira PDC. Kumbali ya mankhwala ndi katundu, daimondi wopangidwa ndi anthu ndi ofanana ndi daimondi wachilengedwe. Kupanga diamondi grit kumaphatikizapo njira yosavuta yopangira mankhwala: kaboni wamba amatenthedwa pansi kwambiri komanso kutentha kwambiri. Mwachizolowezi, komabe, kupanga daimondi sikophweka.

Makristasi amtundu wa diamondi omwe amapezeka mu grit ya diamondi amakhala osiyana. Izi zimapangitsa kuti zinthuzo zikhale zolimba, zakuthwa, ndipo, chifukwa cha kuuma kwa daimondi yomwe ili, imavala kwambiri. M'malo mwake, mawonekedwe osasintha omwe amapezeka mu diamondi yolumikizidwa amachita bwino kukameta ubweya kuposa ma diamondi achilengedwe, chifukwa ma dayamondi achilengedwe ndimakristubulu omwe amasweka mosavuta m'malire awo, amchere.

Daimondi grit siyakhazikika pamatenthedwe otentha kuposa diamondi wachilengedwe, komabe. Chifukwa chitsulo chachitsulo chomwe chatsekedwa mu grit chimakhala ndi chiwongola dzanja chochulukirapo kuposa daimondi, kusiyanasiyana kumayika ma diamondi ndi diamondi pansi pa shear ndipo, ngati katundu ali wokwanira, amachititsa kulephera. Ngati ma bond amalephera, ma diamondi amatayika mwachangu, chifukwa chake PDC imataya kuuma kwake ndikuwongoka ndikukhala osagwira ntchito. Pofuna kupewa kulephera koteroko, odulira PDC ayenera kuzirala mokwanira pakuboola.

Matebulo a diamondi

Popanga tebulo la diamondi, miyala ya diamondi imapangidwa ndi tungsten carbide ndi metallic binder kuti ikhale yopanda miyala ya diamondi. Amakhala ofiira ngati mawonekedwe, ndipo amayenera kupangidwa wokulirapo momwe angathere, chifukwa kuchuluka kwa diamondi kumawonjezera moyo. Ma tebulo apamwamba kwambiri a diamondi ndi ≈2 mpaka 4 mm, ndipo kupita patsogolo kwaukadaulo kumakulitsa makulidwe a tebulo la diamondi. Magawo a carbide a Tungsten nthawi zambiri amakhala ≈0.5 mkati ndipo amakhala ndi mawonekedwe ofanana ndi kukula kwake ngati tebulo la diamondi. The magawo awiri, daimondi tebulo ndi gawo lapansi, amapanga wodula (mkuyu. 4).

Kupanga PDC kukhala mawonekedwe othandizira odulira kumaphatikizapo kuyika miyala ya diamondi, pamodzi ndi gawo lake, mu chotengera chotsitsimutsa kenako nkusefukira ndi kutentha kwambiri.

Odula PDC sangaloledwe kupitilira kutentha kwa 1,382 ° F [750 ° C]. Kutentha kwambiri kumabweretsa kuvala kwachangu, chifukwa kusiyanasiyana kwamatenthedwe pakati pa binder ndi diamondi kumawononga makina amiyala ya diamondi patebulo la diamondi. Mphamvu zama bond pakati pa tebulo la diamondi ndi gawo la tungsten carbide zimasokonezedwanso ndikuwonjezera matenthedwe.


Post nthawi: Apr-08-2021