Mea Paa Paa

He aha ka mea paakiki loa?

ʻO kahi mea paʻa paʻakikī he mea me ka waiwai paʻakikī ma mua o 40 gigapascals (GPa) ke ana ʻia e ka hoʻāʻo paʻakikī Vickers. He mau mea paʻa ʻole hiki ke hoʻopili ʻia me ke kiʻekiʻe electron kiʻekiʻe a me ka covalency paʻa kiʻekiʻe. Ma muli o ko lākou mau waiwai kūʻokoʻa, makemake nui kēia mau mea i nā wahi ʻoihana he nui, akā ʻaʻole i kaupalena ʻia, nā abrasives, polishing a me nā mea hana ʻoki, disc brakes, a me nā lole pale pale.

ʻO ke ala e loaʻa ai nā mea hou superhard

Ma ke ala mua, hoʻohālike ka poʻe noiʻi i nā kaula kalapona covalent pōkole o ke daimana ma o ka hoʻohui ʻana i nā mea māmā e like me boron, carbon, nitrogen, a me ka oxygen.

Hoʻokomo ʻia ka ʻaoʻao ʻelua i kēia mau mea māmā (B, C, N, a me O), akā hoʻokomo pū i nā metala hoʻololi me nā density electron valence kiʻekiʻe e hāʻawi i ka incompressibility kiʻekiʻe. Ma kēia ʻano, ua hui pū ʻia nā metala me nā moduli nui nui akā ʻoi aku ka paʻakikī me nā ʻātoma hana covalent liʻiliʻi e hana i nā mea superhard. ʻO Tungsten carbide kahi hōʻike e pili ana i ka ʻenehana o kēia ala, ʻoiai ʻaʻole ia i manaʻo ʻia he paʻakikī loa. ʻO kahi ʻē aʻe, ua lilo nā boride i hui pū ʻia me nā metala hoʻololi i wahi waiwai o ka noiʻi superhard a ua alakaʻi i nā ʻike e like meReB2,OsB2, aWB4.

Hoʻokaʻawale ʻana o nā mea paʻakikī

Hiki ke hoʻokaʻawale ʻia nā mea superhard i ʻelua mau ʻāpana: nā pūhui intrinsic a me nā pūhui extrinsic. ʻO ka pūʻulu intrinsic ka daimana, cubic boron nitride (c-BN), carbon nitrides, a me nā pūhui ternary e like me B-N-C, nona ka paʻakikī maoli. ʻO ka mea ʻē aʻe, ʻo nā mea extrinsic nā mea i loaʻa ka paʻakikī nui a me nā waiwai mechanical ʻē aʻe i hoʻoholo ʻia e kā lākou microstructure ma mua o ka haku ʻana. ʻO kahi laʻana o nā mea superhard extrinsic he daimana nanocrystalline i ʻike ʻia he nanorods daimana aggregated.

ʻO Diamond ka mea paʻakikī loa i ʻike ʻia a hiki i kēia lā, me ka paʻakikī Vickers ma ka laulā o 70-150 GPa. Hōʻike ʻo Diamond i ka hoʻoili wela kiʻekiʻe a me nā waiwai insulating uila, a ua nui ka nānā ʻana i ka ʻimi ʻana i nā noi kūpono no kēia mea. ʻOkoʻa loa nā waiwai o kēlā me kēia daimana maoli a i ʻole carbonado no nā hana ʻenehana, a no laila ua lilo nā daimana synthetic i mea noiʻi nui.

daimana synthetic

ʻO ke kiʻekiʻe-press synthesis o nā daimana ma 1953 ma Suedena a ma 1954 i ka US i hana ʻia e ka hoʻomohala ʻana i nā mea hana hou a me nā ʻenehana, ua lilo i milestone i ka synthesis o nā mea superhard artificial. Ua hōʻike maopopo ʻia ka synthesis i ka hiki o nā noi kiʻekiʻe kiʻekiʻe no nā hana ʻoihana a hoʻoulu i ka ulu ʻana o ka hoihoi i ke kula.

ʻO ka mea ʻoki PDC kahi ʻano mea paʻakikī loa e hoʻopili i ke daimana polycrystalline me kahi substrate tungsten carbide. ʻO Diamond ke kumu waiwai nui no nā mea ʻoki PDC. Ma muli o ka paʻakikī o nā daimana maoli e hana a lōʻihi ka manawa, ʻoi aku ka nui o ke kumukūʻai, a me ke kumu kūʻai no ka noi ʻoihana, i kēia hihia, ua hana nui ka daimana Synthetic i ka ʻoihana.

Inā makemake ʻoe i nā huahana tungsten carbide a makemake ʻoe i nā ʻike hou aʻe a me nā kikoʻī, hiki iā ʻoe ke CONTACT US ma ke kelepona a i ʻole ka leka uila ma ka hema, a i ʻole SEND US MAIL ma lalo o ka ʻaoʻao.