Superhard Material

Yintoni into enzima kakhulu?

I-superhard material yinto enexabiso lobunzima obudlula i-40 gigapascals (GPa) xa ilinganiswa ngovavanyo lobulukhuni beVickers. Ziziqina ezingenakucinezelwa ezinoxinano oluphezulu lwe-electron kunye ne-bond covalency ephezulu. Ngenxa yeempawu zabo ezizodwa, ezi zixhobo zinomdla omkhulu kwiindawo ezininzi zoshishino ezibandakanya, kodwa zingaphelelanga, i-abrasives, izixhobo zokupholisa kunye nokusika, i-disc brakes, kunye neengubo ezinqabileyo kunye nezikhuselayo.

Indlela yokufumana imathiriyeli entsha enzima kakhulu

Kwindlela yokuqala, abaphandi balinganisa iibhondi zekhabhoni ezimfutshane, ezikhokelela kwidayimani ngokudibanisa izinto ezikhanyayo ezifana ne-boron, ikhabhoni, initrogen kunye neoksijini.

Indlela yesibini ibandakanya ezi zinto zikhaphukhaphu (B, C, N, kunye no-O), kodwa kwakhona yazisa iintsimbi zenguqu ezinoxinzelelo oluphezulu lwe-electron ye-valence ukubonelela ngokungenakuxinwa okuphezulu. Ngale ndlela, iintsimbi ezinemoduli yesixa esikhulu kodwa ubunzima obuphantsi bulungelelaniswa kunye neeathom ezincinci ezibumba icovalent ukuvelisa imathiriyeli enzima kakhulu. I-Tungsten carbide yimbonakaliso ehambelana nezoshishino yale ndlela, nangona ingathathwa njengento enzima kakhulu. Kungenjalo, iibhoridi ezidityaniswe neentsimbi zotshintsho ziye zaba yindawo etyebileyo yophando olunzima kakhulu kwaye ikhokelele ekufumaneni izinto ezinje.ReB2,OsB2, kwayeWB4.

Ukuhlelwa kwezinto ezilukhuni kakhulu

Izinto ezinzima kakhulu zinokuhlelwa ngokubanzi zibe ngamacandelo amabini: iikhompawundi zangaphakathi kunye neekhompawundi zangaphandle. Iqela langaphakathi libandakanya idayimane, i-cubic boron nitride (c-BN), i-carbon nitrides, kunye neekhompawundi ze-ternary ezifana ne-B-N-C, ezinobulukhuni bendalo. Ngokwahlukileyo, izinto ezingaphandle zezo zinobunzima obukhulu kunye nezinye iipropathi zomatshini ezigqitywe yi-microstructure yazo kunokuba zibunjwe. Umzekelo we-extrinsic superhard material yi-nanocrystalline diamond eyaziwa ngokuba yi-aggregated diamond nanorods.

Idayimani yeyona nto inzima eyaziwayo ukuza kuthi ga ngoku, kunye nobunzima beVickers kuluhlu lwe-70-150 GPa. Idayimane ibonisa zombini i-thermal conductivity ephezulu kunye neepropati zokufakelwa kombane, kwaye ingqwalasela eninzi ibekwe ekufumaneni izicelo eziphathekayo zolu lwazi. Iipropati zedayimani zendalo nganye okanye i-carbonado ziyahluka kakhulu ngeenjongo zemizi-mveliso, kwaye ke iidayimani zokwenziwa zaba lugxininiso olukhulu lophando.

Idayimani yokwenziwa

Ukudityaniswa koxinzelelo oluphezulu lweedayimani ngo-1953 eSweden nakwi-1954 e-US kwenzelwa ukuba kuphuhliswe izixhobo ezitsha kunye nobuchule, kwaba sisiganeko esibalulekileyo ekudityanisweni kwemathiriyeli enzima kakhulu. I-synthesis ibonise ngokucacileyo amandla ezicelo zoxinzelelo oluphezulu kwiinjongo zoshishino kunye nokuvuselela umdla okhulayo kwintsimi.

I-PDC cutter luhlobo lwemathiriyeli enzima kakhulu edibanisa idayimani ye-polycrystalline kunye ne-tungsten carbide substrate. Idayimani yeyona nto ingundoqo kubasiki bePDC. Ngenxa yokuba iidayimani zendalo zinzima ukwenza kwaye zithatha ixesha elide, zibiza kakhulu, kwaye zibiza kakhulu kwisicelo semizi-mveliso, kulo mzekelo, idayimani ye-Synthetic idlale indima enkulu kwishishini.

Ukuba unomdla kwiimveliso ze-tungsten carbide kwaye ufuna ulwazi oluthe kratya kunye neenkcukacha, ungaQHAGAMSHELANA NATHI ngefowuni okanye ngeposi ekhohlo, okanye SITHUMELE MAIL emazantsi ephepha.