Tus nqi ntawm cov hlau yog txiav txim ncaj qha los ntawm lawv cov khoom siv tshuaj thiab lub cev. Nyob rau hauv cov ntaub ntawv ntawm xws li ib tug ntsuas raws li hluav taws xob conductivity, qhov kev sib raug zoo tsis yog li ntawd ncaj qha. Cov hlau uas siv hluav taws xob tshaj plaws, thaum ntsuas ntawm chav tsev kub (+ 20 ° C), yog nyiaj.
Tab sis tus nqi siab txwv tsis pub siv cov nyiaj hauv hluav taws xob engineering thiab microelectronics. Cov ntsiab lus nyiaj hauv cov khoom siv no tsuas yog siv thaum muaj kev lag luam ua tau.
Lub ntsiab lus ntawm kev coj ua
Kev siv cov hlau nplaum muaj keeb kwm ntev. Cov kws tshawb fawb thiab cov kws tsim qauv ua haujlwm hauv kev tshawb fawb thiab thev naus laus zis uas siv hluav taws xob tau txiav txim siab ntev rau cov khoom siv rau cov xov hlau, cov khoom siv hluav taws xob, cov neeg sib cuag, cov ntawv luam tawm Circuit Board, thiab lwm yam. Ib lub cev muaj zog hu ua hluav taws xob conductivity pab txiav txim siab cov khoom siv hluav taws xob feem ntau hauv ntiaj teb.
Lub tswvyim ntawm conductivity yog inverse rau hluav taws xob tsis kam. kev nthuav qhia ntauconductivity muaj feem xyuam rau chav tsev ntawm kev tiv thaiv, uas nyob rau hauv lub thoob ntiaj teb system ntawm units (SI) yog ntsuas nyob rau hauv ohms. Chav tsev ntawm hluav taws xob conductivity hauv SI system yog Siemens. Lavxias teb sab xaiv rau chav tsev no yog Sm, thoob ntiaj teb ib qho yog S. Ib qho hluav taws xob conductivity ntawm 1 Sm muaj ib feem ntawm ib qho hluav taws xob network nrog ib tug tsis kam ntawm 1 Ohm.
Kev coj ua
Kev ntsuas lub peev xwm ntawm cov khoom siv hluav taws xob hu ua hluav taws xob conductivity. Cov hlau hluav taws xob feem ntau muaj qhov ntsuas zoo sib xws. Cov yam ntxwv no tuaj yeem txiav txim siab rau txhua yam khoom lossis nruab nrab ntsuas thiab muaj tus lej qhia. Cov hluav taws xob conductivity ntawm ib tug cylindrical conductor ntawm chav tsev ntev thiab chav tsev cross-sectional cheeb tsam muaj feem xyuam rau qhov tshwj xeeb kuj ntawm no conductor.
Lub kaw lus ntawm kev coj ua yog Siemens ib 'meter' - Sm / m. Yuav kom paub seb cov hlau twg yog cov khoom siv hluav taws xob tshaj plaws hauv ntiaj teb, nws txaus los sib piv lawv cov conductivity tshwj xeeb, txiav txim siab sim. Koj tuaj yeem txiav txim siab qhov kev tiv thaiv siv lub cuab yeej tshwj xeeb - microohmmeter. Cov yam ntxwv no yog inversely dependent.
Kev coj tus kheej ntawm cov hlau
Lub tswv yim ntawm cov hluav taws xob tam sim no raws li kev coj ua ntawm cov khoom siv hluav taws xob zoo li sib haum xeeb rau cov khoom siv raws li siv lead ua lattices yam ntxwv ntawm cov hlau. Cov neeg nqa khoom them nyiaj thaum muaj hluav taws xob tam sim no hauv cov hlau yog cov hluav taws xob dawb, thiab tsis yog ions, zoo li cov ntaub ntawv hauv cov kua dej. Nws tau raug sim tsim tias thaum tam sim no tshwm sim hauv cov hlau, tsis muajmuaj kev hloov ntawm cov teeb meem ntawm cov conductors.
Metallic tshuaj txawv ntawm lwm tus hauv cov ntawv cog lus looser ntawm qib atomic. Cov qauv sab hauv ntawm cov hlau yog tus cwj pwm los ntawm qhov muaj ntau ntawm "kho siab" electrons. uas, nyob rau hauv me ntsis cuam tshuam ntawm electromagnetic rog, tsim ib tug ncaj qha ntws. Yog li ntawd, nws tsis yog nyob rau hauv vain uas hlau yog qhov zoo tshaj plaws conductors ntawm hluav taws xob tam sim no, thiab nws yog precisely xws li molecular kev sib cuam tshuam uas txawv cov feem ntau electroly conductive hlau. Lwm cov cuab yeej tshwj xeeb ntawm cov hlau yog raws li cov qauv ntawm cov khoom siv lead ua lattice ntawm cov hlau - siab thermal conductivity.
Top zoo tshaj plaws conductors - hlau
4 hlau ntawm qhov tseem ceeb rau lawv siv raws li cov khoom siv hluav taws xob tau muab faib rau hauv qhov kev txiav txim hauv qab no ntsig txog tus nqi ntawm cov conductivity, ntsuas hauv S / m:
- Silver - 62 500 000.
- Copper - 59,500,000.
- Kub - 45,500,000.
- Aluminium - 38,000,000.
Nws tuaj yeem pom tias cov hlau hluav taws xob feem ntau yog nyiaj. Tab sis zoo li kub, nws yog siv los npaj cov hluav taws xob network nkaus xwb hauv cov xwm txheej tshwj xeeb. Yog vim li cas tus nqi siab.
Tab sis tooj liab thiab txhuas yog qhov kev xaiv ntau tshaj plaws rau cov khoom siv hluav taws xob thiab cov khoom siv cable vim lawv cov hluav taws xob tsis zoo thiab kev pheej yig. Lwm cov hlau tsis tshua muaj siv los ua cov khoom siv.
Yam cuam tshuam rau cov conductivity ntawm hlau
Txawm tias cov hluav taws xob feem ntau siv taucov hlau txo nws cov conductivity yog tias nws muaj lwm yam additives thiab impurities. Alloys muaj qhov sib txawv siv lead ua lattice qauv dua li "ntshiab" hlau. Nws yog qhov txawv los ntawm kev ua txhaum ntawm symmetry, tawg thiab lwm yam tsis xws luag. Conductivity kuj txo nrog qhov kub thiab txias.
Qhov muaj zog tiv thaiv muaj nyob hauv cov alloys pom daim ntawv thov hauv cov khoom cua sov. Nws tsis yog qhov xwm txheej uas nichrome, fechral thiab lwm yam alloys tau siv los ua cov khoom ua haujlwm ntawm cov hluav taws xob thiab cov cua sov.
Cov khoom siv hluav taws xob feem ntau yog cov nyiaj muaj txiaj ntsig, siv ntau dua los ntawm jewelers rau minting npib, thiab lwm yam. Tab sis hauv kev siv tshuab thiab ntsuas, nws cov khoom tshwj xeeb thiab lub cev tau siv dav. Piv txwv li, nyob rau hauv tas li ntawd mus rau siv nyob rau hauv cov chav nyob thiab cov rooj sib txoos nrog txo tsis kam, nyiaj plating tiv thaiv pab pawg neeg los ntawm oxidation. Cov khoom tshwj xeeb ntawm cov nyiaj thiab nws cov alloys feem ntau ua rau nws siv ncaj ncees txawm tias tus nqi siab.
