Dab tsi yog qhov kev siv ntawm polarizing microscopy hauv metallographic tsom xam?
Polarization microscope yog ib qho cuab yeej tseem ceeb rau kev kawm thiab txheeb xyuas cov khoom nrog birefringence siv cov yam ntxwv ntawm lub teeb. Nws tuaj yeem siv los ntawm cov neeg siv rau kev soj ntsuam ib leeg polarization, kev soj ntsuam orthogonal polarization, thiab kev soj ntsuam lub teeb cone. Siv dav hauv kev tshawb fawb thiab tshuaj xyuas hauv thaj chaw xws li geology, chemical engineering, tshuaj, thiab lwm yam, nws tuaj yeem soj ntsuam cov theem siv lead ua kua polymer cov ntaub ntawv, biopolymers, thiab cov ntaub ntawv siv lead ua kua. Nws yog ib qho cuab yeej zoo tshaj plaws rau cov tsev kawm tshawb fawb thiab cov tsev kawm ntawv qib siab los ua kev tshawb fawb thiab kev qhia.
Txoj haujlwm ua haujlwm:
Ob lub lim dej polarization ntawm lub tshuab tsom iav polarizing yog nyob ntawm 90 degrees kom tau txais qhov hu ua "qhov tsaus ntuj". Lub sijhawm no, thaj chaw saib yog dub kiag li. Yog tias tus qauv nthuav tawm isotropy hauv optics (ib qho refractor), txawm tias lub sijhawm tig li cas, qhov kev pom tseem tsaus. Qhov no yog vim hais tias cov kev taw qhia ntawm kev co ntawm linearly polarized lub teeb tsim los ntawm polarizing daim iav tsis hloov. Raws li Marius txoj cai, qhov siv ntawm lub teeb xa mus yog 0. Yog tias tus qauv muaj cov yam ntxwv ntawm birefringence, qhov kev pom yuav ua kom ci dua. Qhov no yog vim hais tias lub teeb linearly polarized emitted los ntawm daim iav polarizing nkag mus rau hauv lub cev birefringent thiab tsim ob hom linearly polarized teeb (o lub teeb thiab e teeb) nrog sib txawv vibration cov lus qhia. Thaum ob hom teeb no dhau los ntawm daim iav polarizing, vim tias e lub teeb tsis ua raws li txoj cai refraction thiab nws cov kev taw qhia polarization tsis yog 90 degree nrog rau daim iav polarizing, cov duab ci tuaj yeem pom nyob rau hauv qhov kev pom los ntawm daim iav polarizing. .
Daim ntawv thov ntawm polarizing microscope hauv metallographic tsom xam:
1, Kev xav ntawm lub teeb polarized ntawm anisotropic hlau sib tsoo qhov chaw.
Kev soj ntsuam anisotropic crystals nyob rau hauv orthogonally polarized lub teeb. Vim qhov sib txawv orientations ntawm txhua grain nyob rau hauv metallographic sib tsoo nto ntawm optically anisotropic hlau, piv txwv li, qhov sib txawv txoj hauj lwm ntawm "optical axis" ntawm txhua grain, lub polarization dav hlau ntawm reflected polarized lub teeb nyob rau hauv txhua lub grain tig ntawm txawv lub kaum sab xis. Los ntawm kev siv lub tshuab ntsuas polarizing, cov nplej sib piv nrog qhov sib txawv ntawm qhov ci tuaj yeem pom hauv qhov muag. Rotating lub theem yog sib npaug rau kev hloov lub kaum sab xis ntawm lub polarization kev taw qhia thiab lub optical axis. Tig lub theem 360 degree thiab saib plaub qhov ci thiab plaub qhov kev hloov pauv tsaus nti hauv qhov pom. Qhov no yog cov nyhuv polarization ntawm anisotropic crystals nyob rau hauv orthogonal polarized lub teeb.
2, Kev xav ntawm lub teeb polarized ntawm isotropic hlau sib tsoo qhov chaw
Thaum cov hlau isotropic pom nyob rau hauv orthogonally polarized lub teeb, vim lawv cov khoom kho qhov muag zoo ib yam hauv txhua qhov kev qhia, lub dav hlau polarization ntawm lub teeb pom kev tsis tuaj yeem tig. Linear polarized teeb yog vertically xwm txheej ntawm isotropic hlau sib tsoo nto, thiab vim hais tias lub teeb pom kev zoo yog tseem linearly polarized, nws yog thaiv los ntawm orthogonal polarizing daim iav. Yog li ntawd, lub teeb pom kev polarized tsis tuaj yeem dhau los ntawm daim iav polarizing, thiab qhov pom ntawm qhov tsaus ntuj, nthuav tawm qhov tshwm sim ploj mus. Lub rotating loading platform kuj tsis muaj kev hloov nyob rau hauv brightness. Qhov no yog qhov tshwm sim ntawm cov hlau isotropic nyob rau hauv orthogonal polarization. Yog tias kawm isotropic hlau nyob rau hauv orthogonal polarization, yuav tsum muaj ib txoj hauv kev tshwj xeeb ntawm kev hloov kho qhov muag ntawm cov khoom siv lead ua qub. Cov kev siv feem ntau suav nrog kev sib sib zog nqus etching lossis kho qhov chaw anodizing. Piv txwv li, qee cov neeg siv sib sib zog nqus etching los soj ntsuam cov koob zoo li martensite thiab thawj cov nplej austenite hauv cov pa roj carbon ntau nickel chromium hlau. Qee tus neeg siv txoj kev no los soj ntsuam martensite, bainite, low-carbon martensite, thiab lwm yam.
3, Polarization tsom xam ntawm non-metallic inclusions
Kev txheeb xyuas qhov tseeb ntawm cov khoom tsis yog xim hlau feem ntau yuav tsum tau siv ntau txoj hauv kev kom tau txais kev txiav txim kom raug. Ntawm lawv, txoj kev metallographic yog ib qho yooj yim thiab ntau txoj hauv kev, tuav txoj haujlwm tseem ceeb. Feem ntau, cov khoom siv kho qhov muag raug tshuaj xyuas nyob rau hauv lub tshuab polarizing siv lub teeb ci, tsaus nti, thiab polarized lub teeb teb.
