Tin thiab txhuas alloy: cov khoom thiab lub npe

2024 Tus sau: Howard Calhoun | [email protected]. Kawg hloov kho: 2023-12-17 10:28

Nws yog qhov zoo tshaj plaws los pib cov lus piav qhia ntawm lub ncauj lus no nrog cov tin thiab txhuas sib cais. Lead, tin thiab alloys ntawm cov khoom no muaj qee yam khoom uas yog vim lawv lub xeev thawj zaug.

piav qhia dav dav ntawm tin

Nws yog ib qho tseem ceeb uas yuav tsum nco ntsoov ntawm no tias ob hom ntawm cov khoom siv raw no txawv. Thawj hom yog hu ua dawb tin, thiab nws yog β-kev hloov kho ntawm cov khoom no. Hom thib ob yog kev hloov kho α, uas zoo dua lub npe hu ua tin grey. Thaum tsiv los ntawm ib qho kev hloov kho mus rau lwm qhov, uas yog los ntawm dawb mus rau grey, qhov kev hloov pauv loj ntawm cov khoom ntim tau tshwm sim, txij li cov txheej txheem xws li tawg ntawm cov hlau rau hauv cov hmoov tshwm sim. Cov cuab yeej no hu ua tin plague. Nws tseem yog ib qho tseem ceeb uas yuav tsum nco ntsoov ntawm no tias ib qho ntawm cov khoom tsis zoo tshaj plaws ntawm cov tin yog nws nyiam Frost. Hauv lwm lo lus, ntawm qhov kub ntawm -20 txog +30 degrees Celsius, kev hloov pauv hloov pauv ntawm ib lub xeev mus rau lwm qhov tuaj yeem pib. Tsis tas li ntawd, kev hloov pauv yuav mus ntxiv txawm tias qhov kub thiab txias tau nce, tab sis tom qab cov txheej txheem tau pib. Vim li no, cov khoom siv raw yuav tsum muab khaws cia rau hauv qhov chaw uas muaj qhov kub thiab txias.

khoom tin thiab txhuas

hais tias tin,txhuas thiab alloys ntawm cov ntaub ntawv no muaj tsawg heev cov khoom sib xws. Piv txwv li, lub purer lub tin, ntau dua lub caij nyoog uas nws yuav raug cuam tshuam los ntawm tus kab mob plague. Lead, nyob rau hauv lem, tsis undergo allotropic transformations.

Txawm li cas los xij, nws tseem tsim nyog sau cia tias cov tshuaj ntxiv tau siv los ua kom qeeb ntawm qhov kev hloov pauv hauv tin. Qhov zoo tshaj plaws, cov ntaub ntawv xws li bismuth thiab antimony pom lawv tus kheej. Qhov sib ntxiv ntawm cov tshuaj no nyob rau hauv ib lub ntim ntawm 0.5% yuav txo tus nqi ntawm allotropic transformation rau yuav luag 0, uas txhais tau hais tias dawb tin tuaj yeem suav hais tias ruaj khov. Nws tuaj yeem raug sau tseg ntawm no tias tsawg dua, tab sis tseem, cov hlau nplaum thiab cov hlau lead yog siv rau tib lub hom phiaj.

Yog tias peb tham txog cov khoom ntawm cov hlau lead, ces nws muaj cov ntsiab lus melting ntau dua - 327 degrees Celsius dua li tin - 232 degrees. Qhov ceev ntawm txhuas nyob rau hauv chav tsev kub yog 11.34 g / cm3.

Tin thiab txhuas yam ntxwv

Nws tsim nyog pib nrog qhov tseeb tias recrystallization ntawm kev ua hauj lwm-hardened tin, txhuas thiab alloys tshwm sim ntawm qhov kub thiab txias uas xav tau hauv qab chav tsev kub. Vim li no, lawv cov txheej txheem kub.

Qhov taw qhia dav dav yog qhov tiv thaiv corrosion nyob rau hauv huab cua. Txawm li cas los xij, qhov sib txawv me ntsis yog nyob rau hauv kev tiv thaiv corrosion nyob rau hauv kev cuam tshuam ntawm cov khoom me. Piv txwv li, txhuas manifests nws tus kheej zoo tshaj plaws thaum interacting nrog concentrated compositions ntawm tej acids - sulfuric, phosphoric, thiab lwm yam. Tin, nyob rau hauv lem, zoo tshaj resists daws los ntawm.zaub mov acids. Lub peev xwm ntawm cov tshuaj no nyias kuj txawv. Tin yog siv dav rau tinning tin, thaum cov hlau lead tau pom nws txoj hauv kev rau hauv cov khoom siv sulfuric acid.

Alloy systems

Ntawm no nws yog ib qho tseem ceeb uas yuav tau pib nrog qhov tseeb tias cov hlau nplaum thiab cov hlau lead yog cov khoom siv fusible ntau dua li sib cais. Xws li kev sib tov yog feem ntau siv los ua cov solders, rau kev tsim cov typographic fonts, rau casting fuses, thiab lwm yam. Xws li ib tug system li "tin - lead" belongs rau pab pawg neeg ntawm eutectic hom. Ib qho tseem ceeb ntawm tag nrho cov ntaub ntawv nyob rau hauv pawg no yog hais tias lawv melting kub nyob rau hauv lub cheeb tsam ntawm 120 mus rau 190 degrees Celsius. Tsis tas li ntawd, muaj pab pawg ntawm ternary eutectics. Ib qho piv txwv yog tin-lead-zinc alloy system. Qhov kub ntawm cov khoom siv no poob qis dua, thiab nws qhov kev txwv yog 92-96 degrees Celsius. Yog tias koj ntxiv cov khoom thib plaub rau cov hlau, tom qab ntawd lub melting kub yuav poob mus rau 70 degrees. Yog hais tias peb tham txog kev siv ib tug alloy ntawm tin nrog txhuas raws li solder, ces feem ntau mus txog 2% ntawm ib yam khoom xws li antimony yog nkag mus rau hauv lawv muaj pes tsawg leeg. Qhov no yog ua los txhawm rau txhim kho qhov ntws ntawm cov solder. Nws yog ib qho tsim nyog sau cia ntawm no tias qhov kub ntawm qhov kub tuaj yeem tswj tau los ntawm "tin / lead" piv. Fusible raw khoom melts ntawm 190 degrees.

Babbits

Nrog lub npe ntawm cov hlau nplaum thiab cov hlau lead, twb pom lawm - nws yog eutectic. Cov pab pawg no ntawm cov khoom uas muaj xws li ib tug muaj pes tsawg leeg yog dav siv nyob rau hauv zus tau tej cov bearing alloys, uas yog hu ua "babbits". Cov khoom siv no yog siv los ua cov khoom ntim rau cov kabmob. Qhov tseem ceeb tshaj plaws ntawm no yog xaiv cov khoom tsim nyog kom nws thiaj li yooj yim khiav mus rau hauv cov ncej. Thaum xub thawj siab ib muag, nws zoo nkaus li tias qhov loj ntawm tin thiab txhuas alloys nrog ntau yam solders yog ib txoj hauv kev zoo heev. Txawm li cas los xij, hauv kev muaj tiag, qhov no tsis yog qhov tseeb kiag li. Cov ntaub ntawv zoo li no tau dhau los ua mos heev, thiab cov coefficient ntawm kev sib txhuam ntawm cov ncej thiab cov ntxig ntxig yog siab. Nyob rau hauv lwm yam lus, thaum lub sij hawm ua hauj lwm, lawv rhuab ntau dhau lawm, vim hais tias ntawm no, low-melting hlau pib "stick" rau lub ncej. Txhawm rau zam qhov tsis txaus no, ib qho me me ntawm cov khib nyiab ntxiv tau pib ntxiv. Ua li no, cov khoom tau txais uas yog mos thiab tawv tib lub sijhawm.

Kev sib piv

Yuav kom ua tiav ib yam khoom uas muaj qhov txawv txav, cov tshuaj hauv qab no tau siv. Qhov tseem ceeb tshaj plaws yog tias lawv pw tam sim ntawd hauv ob theem α + β. Crystals ntawm β-theem yog enriched nrog solder xws li antimony. Lawv ua raws li cov khoom nkig. Lub α-theem crystals, nyob rau hauv lem, yog ib tug mos mos thiab yas puag. Txhawm rau kom tsis txhob muaj qhov tsis zoo xws li melting ntawm cov khoom siv lead ua thiab lawv qhov nce, lwm qhov sib xyaw yog ntxiv rau qhov sib tov - tooj liab. Yog liYog li, los ntawm ib daim ntawm cov hlau lead thiab tin nrog rau qhov sib ntxiv ntawm lwm yam khoom, nws muaj peev xwm tsim ib tug babbit bearing khoom uas combines ob yam zoo sib xws - hardness thiab softness. Babbit B83 tau dhau los ua cov khoom lag luam classic thiab feem ntau ntawm cov khoom lag luam no. Cov muaj pes tsawg leeg ntawm no alloy yog raws li nram no: 83% Sn; 11% Sb; 6% Cu.

Kev xaiv

Nws yuav tsum tau hais tias los ntawm qhov pom ntawm kev lag luam, tin-based babbits yog qhov tsis zoo, vim tias cov khoom siv no raug nqi ntau heev. Tsis tas li ntawd, tin nws tus kheej yog suav tias yog ib qho khoom tsis tshua muaj. Rau ob qho laj thawj no, lwm cov bearings tau tsim los ntawm cov hlau lead, antimony thiab tooj liab. Nyob rau hauv no muaj pes tsawg leeg, antimony crystals ua raws li lub hauv paus khoom. Lub hauv paus mos yog ib qho ncaj qha alloy ntawm txhuas thiab antimony. tooj liab yog siv nyob rau hauv tib txoj kev raws li cov hlau lead nyob rau hauv lub yav dhau los muaj pes tsawg leeg, uas yog, los tiv thaiv lub hauv paus crystals los ntawm floating.

Txawm li cas los xij, ntawm no nws tsim nyog hais txog qhov tsis txaus. Cov hmoov txhuas / antimony eutectic tsis yog ductile li tin theem. Yog li ntawd, qhov chaw ua nyob rau hauv txoj kev no raug kev txom nyem los ntawm kev hnav sai. Txhawm rau tiv thaiv qhov teeb meem no, koj tseem yuav tsum tau ntxiv qee qhov ntawm cov tin. Kev siv zinc-tin-lead ternary eutectics tsis ntau heev.