Qhov sib txawv tseem ceeb ntawm cov ciam teb ntawm cov qoob loo thiab cov ciaj ciam ntxaib yog cov ciam teb tuaj yeem tshwm sim ntawm txhua hom siv lead ua nplej, whereas ntxaib ciam tuaj yeem tshwm sim tsuas yog ntawm cov muaju uas muaj tib lub qauv siv lead ua lattice.
Ib thaj tsam hauv thaj tsam ntawm crystallography yog qhov sib cuam tshuam ntawm ob chav nyob ntawm cov iav siv lead ua. Cov qauv no yog hu ua nplej lossis crystallites. Peb tuaj yeem soj ntsuam cov ciam teb no hauv cov khoom siv polycrystalline, thiab cov no paub tias yog qhov tsis xws ntawm cov khoom siv.
Txoj Kev Ciam Teb yog dab tsi?
Grain ciam teb yog qhov sib cuam tshuam ntawm ob lub nplej hauv cov khoom siv polycrystalline. Feem ntau, cov ciam teb hauv cov khoom siv polycrystalline yog 2D tsis xws luag hauv cov qauv siv lead ua. Qhov teeb meem no yuav txo tau cov hluav taws xob thiab thermal conductivity ntawm cov khoom. Cov ciam teb no yog cov chaw nyiam rau qhov pib ntawm corrosion. Lawv kuj yog cov chaw nyiam rau nag lossis daus ntawm cov theem tshiab los ntawm cov khoom. Cov qoob loo ciam teb tsis xws luag yog qhov tseem ceeb hauv ntau txoj hauv kev ntawm kev nkag.
Ntxiv rau, cov ciam teb no zoo li cuam tshuam kev txav ntawm kev txav mus los ntawm cov khoom siv, yog li txo cov crystallite loj, uas ua rau kev txhim kho cov neeg kho tshuab lub zog. Qhov tshwm sim no tau piav qhia los ntawm Hall-Petch kev sib raug zoo. Txoj kev kawm ntawm cov ciam teb, lawv cov khoom siv tshuab thiab hluav taws xob tau piav qhia hauv qab ntawm cov khoom siv science.
Peb tuaj yeem piav qhia txog ib thaj tsam ntawm cov nplej los ntawm kev taw qhia ntawm ciam teb rau ob lub nplej thiab 3D kev sib hloov uas peb yuav tsum coj cov nplej mus rau qhov sib npaug. Yog li ntawd, ib tug ciam teb feem ntau muaj 5 macroscopic degrees ntawm kev ywj pheej. Txawm li cas los xij, feem ntau yog ciam teb tsuas yog piav qhia raws li kev sib raug zoo ntawm cov nplej nyob sib ze.
Daim duab 01: Cov duab sib txawv ntawm cov kab lis kev cai
Nyob ntawm Grain Boundaries
Muaj ob hom qoob loo uas ciam teb siab thiab qis qis. Qhov kev faib tawm no nyob ntawm qhov kev tsis sib haum xeeb ntawm ob qho nplej. Cov ciam teb qis qis tseem hu ua subgrain ciam teb, thiab cov ciam teb no muaj qhov tsis zoo uas tsawg dua 15 degrees. Nyob rau hauv sib piv, lub kaum sab xis grain ciam teb muaj lawv misorientations ntau tshaj 15 degrees. Feem ntau, cov ciam teb siab siab yuav ua rau muaj kev ywj pheej ntawm kev tsis ncaj ncees.
Twin Boundary yog dab tsi?
Twin ciam teb yog qhov sib cuam tshuam ntawm ob lub ntsej muag sib cais uas yog daim iav duab ntawm ib leeg. Hauv lwm lo lus, ntxaib ciam teb tshwm sim ntawm cov qauv siv lead ua sib cais uas muaj tib lub ntsej muag siv lead ua. Hom kev tshwm sim no kuj hu ua crystal twinning. Feem ntau, ib tug ntxaib ciam teb yog symmetrical ntawm ob sab. Ob tug ciam teb kuj muaj npe raws li qhov chaw sib xyaw lossis ntxaib dav hlau.
Peb tuaj yeem faib ob thaj tsam sib txawv raws li txoj cai ntxaib. Feem ntau, cov kev cai ntxaib yog tshwj xeeb rau cov tshuab siv lead ua. Ntxiv mus, hom ntxaib ciam teb tuaj yeem pab tau rau kev txheeb xyuas cov ntxhia.
Daim duab 02: Quartz-Japan Twin
Feem ntau, ib tug ntxaib ciam teb tuaj yeem hloov pauv mus rau ib thaj tsam ntawm hom ntau. Qhov no tshwm sim los ntawm kev tsim cov phab ntsa ntawm qhov tsis sib haum xeeb dislocations thaum lub sij hawm dislocation txheej txheem, uas tshwm sim los ntawm cov ciam teb.
Dab tsi yog qhov txawv ntawm Grain Boundary thiab Twin Boundary?
Grain ciam teb yog qhov sib cuam tshuam ntawm ob lub nplej hauv cov khoom siv polycrystalline. Twin ciam teb yog qhov sib cuam tshuam ntawm ob lub ntsej muag sib cais uas yog daim iav duab ntawm ib leeg. Yog li ntawd, qhov sib txawv tseem ceeb ntawm cov ciam teb thiab cov ciam teb ntxaib yog qhov ciam teb tuaj yeem tshwm sim ntawm txhua hom siv lead ua nplej, qhov ntxaib ciam tuaj yeem tshwm sim tsuas yog ntawm cov muaju uas muaj tib lub qauv siv lead ua lattice.
Cov infographic hauv qab no qhia txog qhov sib txawv ntawm cov ciam teb thiab cov ciam teb ntxaib hauv daim ntawv teev npe.
Summary – Grain Boundary vs Twin Boundary
Ib thaj tsam hauv thaj tsam ntawm crystallography yog qhov sib cuam tshuam ntawm ob chav nyob ntawm cov siv lead ua lattice. Tau txais ciam teb yog hom kev ciam teb, thaum ntxaib ciam teb yog ib hom kev ciam teb. Qhov sib txawv tseem ceeb ntawm cov ciam teb thiab cov ciam teb ntxaib yog qhov ciam teb tuaj yeem tshwm sim ntawm txhua hom siv lead ua nplej, qhov ntxaib ciam tuaj yeem tshwm sim tsuas yog ntawm cov muaju uas muaj tib lub qauv siv lead ua lattice.
