Bronze vs. Brass – Qhov txawv yog dab tsi?
Ntev ua ntej hnub ntawm txhuas thiab hlau, hlau alloys tau tsim, cov ntaub ntawv tsim los ntawm kev sib koom ua ke ob qho tib si hlau ua ke. Los ntawm kev ua li ntawd, cov txiaj ntsig alloy tsis tsuas yog khaws qee cov khoom ntawm txhua lub caij, tab sis tuaj yeem muaj cov khoom tshiab tsis pom nyob rau hauv ib qho, uas tau hloov pauv peb cov khoom siv niaj hnub xaiv. Ob lub alloys uas pib qhov kev hloov pauv no yog tooj liab thiab tooj dag, cov hlau qub qub uas tau muab pov tseg hauv kuv lub tebchaws rau ntau tshaj plaub lossis tsib txhiab xyoo. Cov hlau no muab lub ntsiab lus pib rau tag nrho lwm cov alloys, thiab tsab xov xwm no yuav tshawb txog bronze thiab tooj dag thiab qhov sib txawv ntawm lawv. Lub cev, tshuaj, thiab txhua yam khoom ntawm bronze thiab tooj dag yuav qhia ntxaws, nrog rau txoj hauv kev uas lawv tseem siv niaj hnub no. Kab lus no yog tsom qhia tias cov hlau no, thaum laus dua li lwm cov khoom siv engineering, tseem yog cov khoom tseem ceeb rau peb txoj kev vam meej nyob rau niaj hnub no.
Bronze
Bronze yog qhov tshwm sim ntawm kev ntxiv tin rau tooj liab, txawm hais tias feem ntau muaj ntau cov ntsiab lus ntxiv, raws li bronze tau tshawb pom los ntawm Suav nyob ib ncig ntawm ntau txhiab xyoo BC, ua ntej cov chemistry raug tsim. Niaj hnub no, bronze yog suav hais tias yog ib chav kawm ntawm tooj liab alloys, txhais los ntawm lawv cov khoom ua haujlwm thiab cov ntsiab lus tshwj xeeb alloying. Cov hlau xws li txhuas, manganese, antimony, npib tsib xee, zinc, silicon, thiab lwm yam tau pom los txhim kho cov khoom ntawm bronze, yog li cov neeg tsim qauv tam sim no muaj ntau yam bronze qib xaiv los ntawm.
Bronze feem ntau reddish xim av/golden nyob rau hauv cov xim thiab yog nkig, tab sis sib dua li cam khwb cia hlau. Nws muaj qhov sib txheeb ze ntawm 8.8 g / cm3 thiab pom muaj kev sib txhuam qis thaum sib cuag nrog lwm cov hlau. Nws yooj yim ua cua sov thiab hluav taws xob, nrog rau qhov chaw melting ntawm 950 - 1050 degree, nyob ntawm cov ntsiab lus tin. Vim nws cov ntsiab lus tooj liab siab, nws oxidizes hauv huab cua, uas muab bronze nws txawv mottled patina. Qhov no oxidation tiv thaiv bronze los ntawm corroding, tshwj xeeb tshaj yog nyob rau hauv dej ntsev ib puag ncig; Txawm li cas los xij, yog tias cov tshuaj chlorine tuaj yeem hnov mob nrog cov tooj liab, cov txheej txheem hu ua "bronze disease" pib, thiab corrosion ua rau corrosion ntau dua, maj mam rhuav tshem cov hlau thaum lub sijhawm. Nws tiv taus dej ntsev ua rau tooj liab muaj txiaj ntsig zoo rau lub nkoj fittings thiab underwater marine qhov chaw, nrog rau cov duab puab uas yuav tsum tau tiv thaiv los ntawm degradation nyob rau hauv ib puag ncig sab nraud. Nws muaj cov khoom zoo tshaj plaws casting thiab tuaj yeem yooj yim nrum rau hauv bearings, clips, hluav taws xob sib txuas, springs, thiab lwm yam.
tooj dag
tooj dag tau pom nyob ib ncig ntawm 500 BC thiab yog ib qho alloy ntawm tooj liab thiab zinc, txawm hais tias nws kuj muaj lwm cov ntsiab lus, ib yam li tooj liab. Vim tias muaj ntau qhov sib tshooj ntawm tooj dag thiab tooj liab, tooj dag feem ntau qhia los ntawm nws cov feem ntau ntawm zinc thiab cov txheeb ze tsis muaj tin (txawm hais tias tsis meej pem. Tin-plated tooj dag alloys kuj muaj nyob, plooj cov kab ntxiv). Lead yog ib qho khoom siv ntxiv rau tooj dag los txhim kho nws txoj haujlwm ua haujlwm, nrog rau lwm cov khoom tshwj xeeb uas ua rau cov tooj dag alloy.
Brass yog ci kub, tooj liab, lossis txawm tias nyiaj, nyob ntawm qhov piv ntawm zinc rau tooj liab. Nws yog ductile ntau dua bronze thiab nthuav tawm zoo sib xws tsis tshua muaj kev sib txhuam thaum sib cuag nrog lwm yam hlau. Nws muaj qhov ntom ntawm li 8.73 g / cm3 thiab lub melting point tsawg li 900-1000 degree , nyob ntawm cov alloy. Cov tooj dag yog cov khoom siv hluav taws xob kub thiab tiv taus corrosion, tshwj xeeb tshaj yog rau galvanic corrosion los ntawm seawater. Nws cam khwb cia zoo, yog qhov ruaj khov thiab txaus nyiam, thiab txawm tias muaj qee yam tshuaj tua kab mob vim nws cov ntsiab lus tooj liab siab. Feem ntau siv rau tooj dag yog nyob rau hauv cov twj paj nruag, hniav trim, screws, radiators, mos txwv casings, thiab lwm yam.
