Zirconium alloys: muaj pes tsawg leeg, khoom, daim ntawv thov

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

Kev siv zirconium alloy yog tam sim no dav dav hauv tshuaj thiab nuclear zog. Hauv lwm qhov kev lag luam, cov khoom siv no kuj siv tau, tab sis tsawg dua. Nws yog tsim nyog sau cia tias ntau yam alloys los ntawm cov khoom siv raw no tau txais koob meej. Los ntawm nws tus kheej, zirconium tsis tau dhau los ua cov khoom siv nrov, vim nws qhov zoo yog qhov phem dua li cov hlau ntawm tib lub hlau.

cov ntaub ntawv dav dav

Zirconium (Zr) yog ib qho khoom ntawm lub sijhawm lub sijhawm uas nws tus lej atomic yog 40 thiab nws qhov hnyav atomic yog 91.22. Nyob rau hauv ib txwm muaj thiab nyob rau hauv ib txwm muaj, cov khoom no yog cov hlau nplaum nrog cov xim dawb dawb. Qhov ceev ntawm cov khoom siv raw no nce mus txog 6.45 g / cm33. Cov hlau no nyob rau hauv nws daim ntawv ntshiab, uas tsis muaj impurities, yog qhov txawv los ntawm qhov tseeb hais tias nws muaj ib tug heev ductility, thiab nws yog heev yooj yim mus ua ob qho tib si txias thiab kub. Nws yog ib qho tsim nyog sau cia ntawm no tias cov khoom siv raw, xws li titanium, piv txwv li, yuav plam nws cov khoom siv dag zog yog tias nws tau ua ke nrog impurities ntawm cov khoom tsis yog xim hlau. Zirconium thiab oxygen yog suav tias yog cov sib xyaw ua ke phem tshaj plaws.

Cov khoom siv thiaballoy

Zirconium nws tus kheej yog qhov txawv los ntawm qhov tseeb tias nws muaj kev sib haum xeeb rau ntau cov kua qaub. Cov khoom siv raw no tsis yaj hauv ib puag ncig xws li nitric thiab hydrochloric acid lossis alkali. Qhov no feature yog qhov tseem ceeb. Nyob rau hauv nws lub hauv paus, ntau zirconium alloys yog tsim. Piv txwv li, yog tias koj noj cov khoom siv magnesium alloys thiab ntxiv cov khoom xws li zirconium rau lawv, cov khoom yuav dhau los ua cov tshuaj tiv thaiv corrosion. Yog tias koj tsim ib qho alloy ntawm titanium thiab zirconium, ces cov kua qaub tiv thaiv ntawm thawj lub caij yuav nce.

Nws tseem tsim nyog sau cia tias tag nrho cov zirconium alloys nrog rau lwm cov hlau yog cov yam ntxwv los ntawm qhov tseeb tias lawv tsis poob lawv qhov hnyav nyob rau hauv qhov kub thiab txias, qhov tsis kam rau cov neeg kho tshuab poob siab tseem nyob rau theem siab heev. Ib qho piv txwv yog magnesium alloy nrog ob peb feem pua zinc thiab tsuas yog ob peb feem kaum ntawm ib feem zirconium. Cov hlau uas tshwm sim yuav luag yuav luag ob npaug li muaj zog li magnesium, thiab nws tseem tuaj yeem tswj nws lub zog ntawm qhov kub txog 200 degrees Celsius.

Kev piav qhia ntawm nta

Zirconium alloys nquag siv hauv thaj chaw xws li roj av cladding, roj channel kav, thiab ntau qhov chaw ntawm cov roj sib dhos. Zirconium nws tus kheej kuj yog tus yam ntxwv los ntawm qhov tseeb hais tias cov neutron absorption cross section yog qhov tsawg. Raws li qhov ntsuas no, nws tsuas yog thib ob rau cov tshuaj xws li magnesium thiab beryllium. Tsis tas li ntawd, lub melting point ntawm zirconium yog siab heev.

Zirconium alloys siv nyob rau hauv ntau qhov kev lag luam yog tus cwj pwm los ntawm qhov tseeb tias lawv muaj kev tiv thaiv corrosion siab heev hauv dej, hauv chav dej sib xyaw, hauv cov dej saturated thiab superheated rau qhov kub ntawm li 350-360 degrees Celsius. Nws tseem tsim nyog sau cia tias qhov ntsuas kub no yuav tsum tau nce mus rau qhov muaj nqis siab dua yav tom ntej.

Alloy parameters

Cov khoom ntawm zirconium alloys nyob rau hauv cov nqe lus ntawm txhua yam kev ruaj ntseg yog siab heev, uas tsis tuaj yeem hais txog cov zirconium ntshiab. Nws yog los ntawm alloying tias lub zog siab ntawm cov khoom tiav. Piv txwv li, ib qho alloy xws li niobium (Nb) thiab 1% zirconium (Zr) yuav yog tus cwj pwm los ntawm qhov tseeb tias lub zog tawm los ntawm cov khoom ntawm qhov kub ntawm 20, 200, 300 thiab 400 degrees Celsius yuav yog 200, 160, 120. thiab 90 MPa. Qhov no alloy yog nquag siv rau roj pas nrig cladding. Thiab, piv txwv li, yog tias koj hloov cov ntsiab lus ntawm zirconium alloy nrog niobium, uas yog, nce cov ntsiab lus zirconium mus rau 2.5%, ces lub zog tawm los yuav nce mus rau 280, 220, 200 thiab 180 MPa, ntawm tib qhov kub.

Txawm li cas los xij, cov ntaub ntawv no muaj lawv qhov tsis zoo. Qhov tsis zoo muaj xws li qhov tseeb tias cov hlau alloy nrog zirconium hloov mus rau qhov siab dhau heev thaum qhov kub nce mus txog 320-350 degrees Celsius thiab siab dua. Lwm qhov tsis zoo yog tias Zr nquag yaj hydrogen, uas feem ntau tshwm sim thaum corrosion. Vim li no, cov khoom xws li zirconium hydrides yuav raug tsim, uas txo cov ductility ntawm raw khoom, uas ua rau cov hlau nkig.

Zirconium hauv tshuaj

Zirconium alloys yog siv heev hauv tshuaj. Cov kws tshawb fawb los ntawm kev sim tau pom tias txawm tias hnav zirconium bracelets yooj yim tuaj yeem pab kho qee yam kab mob, thiab nws tuaj yeem ua rau tib neeg txoj kev noj qab haus huv tag nrho.

Hnub no, cov tshuaj cog (retainers) feem ntau yog siv rau hauv cov tshuaj xws li traumatology thiab maxillofacial phais. Fixators yog siv rau pob txha, kho cov pob txha kom lawv tsis txav mus. Nws yog nyob rau hauv cov ntaub ntawv no uas ib tug muaj peev xwm paub qhov txawv xws li zoo ntawm kev siv zirconium alloys xws li: siab biological compatibility (lub ntsiab lus tsis muaj kev tsis haum tshuaj ntawm tib neeg lub cev rau xws li ib tug alloy los yog tsis kam), siab zog yam ntxwv ntawm cov alloy, uas yog ib qho tseem ceeb heev. rau fixators. Nws tseem tsim nyog sau cia tias qhov tsis muaj kev tsis lees paub lossis kev ua xua rau cov tshuaj no ua rau muaj qhov tseeb tias tsis tas yuav rov ua haujlwm phais kom tshem tawm cov retainer yog tias lub cev dheev pib tsis kam cog.

Zirconium hauv kev lag luam nuclear fais fab

Txog 50s ntawm lub xyoo pua xeem, nws tau ntseeg tias zirconium tsis haum rau siv hauv cheeb tsam no. Txawm li cas los xij, nws yog nyob rau hauv 50s. Thawj thawj zaug, cov khoom tau txais uas tau ua kom huv huv los ntawm cov impurity xws li hafnium. Tom qab purification, nws muab tawm tias cov zirconium ntshiab muaj ib qho me me thermal neutron absorption hla ntu. Nws yog qhov zoo no uas tau los ua qhov tseem ceeb thiab ua rau nws tuaj yeem siv zirconium alloys hauv kev lag luam hluav taws xob nuclear.

Nws yuav tsum tau ntxiv tias tsuas yog purified zirconium tsis tuaj yeem siv vim tias qhov corrosion kuj tsawg dhau hauv dej kub. Tom qab ntawd, nws tau txiav txim siab siv zirconium-based alloys. Lawv tau ua pov thawj tias lawv muaj nqis nyob rau hauv cov cua txias reactors thiab qhov chaw zoo sib xws.

Kev siv dav dav ntawm cov hlau

Zirconium yog dav siv los ua cov khoom sib xyaw. Qhov no yog vim qhov tseeb tias cov hlau uas cov tshuaj no ntxiv ua kom sov-resistant, acid-resistant, thiab lwm yam. Ntawd yog, cov hlau alloy ntawm cov hlau thiab zirconium zoo heev tshaj qhov pib raw khoom hauv nws cov yam ntxwv.

Ferrozirconium yog siv dav heev. Nws yog ib qho alloy ntawm zirconium thiab hlau. Cov ntsiab lus ntawm cov khoom alloying Zr ncav cuag 20% ntawm tag nrho cov huab hwm coj. Cov khoom no yog siv hauv metallurgy ua deoxidizer thiab degasser rau hlau. Piv txwv li, aluminium-zirconium alloys yog suav hais tias yog cov feem ntau resistant rau corrosion thiab siv nyob rau hauv cathode daim phiaj rau lub tshuab nqus tsev raj. Cov ntsiab lus ntawm Zr nyob rau hauv xws li ib tug alloy tsis ntau tshaj 3% ntawm tag nrho cov loj.

Hauv ferrous metallurgy, ntxiv rau ferrozirconium, feem ntau siv Zr thiab silicon alloy. Nws yog siv rau degassing steel. Ib qho alloy ntawm tooj liab thiab zirconium yog dav siv rau kev tsim cov khoom siv hluav taws xob rau cov khoom siv hluav taws xob.

Nrhiav zirconium

Nws tsim nyog sau cia tias zirconium yog qhov tsis tshua muaj. Cov ntsiab lus ntawm cov khoom no nyob rau hauv lub ntiaj teb crust tsis tshaj0.025% ntawm qhov hnyav. Zirconium occupies kaum ob kab nyob rau hauv lub rooj ntawm prevalence ntawm hlau. Cov khoom siv raw no yog dispersed heev, thiab yog li ntawd nws yog ib qho nyuaj heev los nrhiav ib qho loj deposits ntawm nws. Nws yog feem ntau pom raws li ib tug tshuaj compound nyob rau hauv lub lithosphere, raws li zirconium nws tus kheej yog ib tug lithophile keeb.