Tshawb xyuas cov txheej txheem ntxiv dag zog ntawm cov khoom siv tooj liab alloy
Feem ntau siv cov txheej txheem ntxiv dag zog rau tooj liab thiab tooj liab alloys muaj xws li: deformation ntxiv dag zog, nplua nplej ntxiv dag zog, cov khoom muaj zog ntxiv, hnub nyoog nag lossis daus (tej nag xob nag cua) ntxiv dag zog, dispersion ntxiv dag zog, cov khoom sib xyaw ntxiv, thiab ntxiv cov kab lus.
1. Lub zog deformation
Deformation reinforcing yog los txhim kho lub zog thiab hardness ntawm tooj liab alloy los ntawm cov yas deformation. Nws yog ib qho ntawm feem ntau siv ntxiv dag zog txoj kev ntawm tooj liab alloy. Txij li cov khoom siv lead ua tsis zoo uas ua los ntawm kev ua haujlwm txias tsis tshua muaj kev cuam tshuam rau cov khoom siv hluav taws xob, qhov kev siv dag zog no txhim kho lub zog thaum tseem ua rau cov hlau ua tau zoo heev. Cov yam ntxwv ntawm deformation ntxiv dag zog yog tias thaum lub zog ntawm cov khoom nce, nws cov plasticity poob sai sai, thiab cov hluav taws xob conductivity kuj yuav txo qis me ntsis vim qhov nce ntawm qhov sib txawv ntawm qhov ceev. Tsis tas li ntawd, thaum qhov kev pab cuam kub nce, cov khoom yuav raug rov qab thiab recrystallization txheej txheem thiab soften, thiab ib qho deformation ntxiv dag zog tuaj yeem tsuas yog ua kom lub zog ntawm cov hlau mus rau qhov txwv, yog li nws feem ntau siv ua ke nrog lwm txoj kev ntxiv dag zog.
2. Fine grain ntxiv dag zog
Fine grain reinforcing yog siv cov kev ntsuas ceev ceev lossis kev kho cua sov kom tau txais cov nplej zoo thaum lub sij hawm casting. Qee cov kab hlau nplaum tseem tuaj yeem muab ntxiv los ua kom zoo dua cov nplej. Lub grain loj yog txo, lub zog ntawm cov alloy yog nce, thiab nws muaj me ntsis cuam tshuam rau cov hluav taws xob conductivity ntawm lub alloy. Yog li ntawd, nplua nplej ntxiv dag zog tau dhau los ua ib txoj hauv kev ntxiv dag zog rau tooj liab alloys. Qhov zoo tshaj plaws ntawm kev nplua-grain ntxiv dag zog yog tias nws tuaj yeem txhim kho plasticity ntawm cov khoom thaum txhim kho lub zog ntawm cov khoom. Qhov no yog vim hais tias tom qab cov nplej ua kom zoo, qhov kev ntxhov siab tshwm sim los ntawm kev cuam tshuam ntawm cov ciam teb thaum cov khoom deformed tuaj yeem txo tau zoo, ncua kev pib ntawm cov kab nrib pleb, thiab ntau qhov deformation tuaj yeem ua tiav ua ntej cov khoom tawg. Grain refinement yog dav siv vim qhov zoo dua no.
3. Cov kua nplaum ua kom muaj zog
Qhov tshwm sim ntawm kev ua kom lub zog thiab hardness ntawm cov hlau los ntawm kev sib koom ua ke ntawm cov ntsiab lus solute los ua ib qho kev daws teeb meem yog hu ua solid solution strengthening. Cov tshuaj tiv thaiv muaj zog tshwm sim vim tias qhov sib cais ntawm cov atoms distortion ua rau muaj kev cuam tshuam ntawm cov khoom siv lead ua ntawm cov kuab tshuaj hlau, yog li ua rau muaj kev cuam tshuam rau kev txav mus los. Kev xyaum tau ua pov thawj tias kev tswj xyuas cov ntsiab lus ntawm cov ntsiab lus hauv cov khoom siv tau zoo tuaj yeem txhim kho lub zog thiab hardness ntawm cov khoom thaum tseem tuav tau zoo plasticity thiab toughness. Piv txwv li: ntxiv 19% npib tsib xee rau tooj liab tuaj yeem nce phib ntawm cov hlau los ntawm 220MPa rau 380 ~ 400MPa, thiab hardness ntawm HB44 mus rau HB70, thaum lub plasticity tseem tuav ψ=50%. Yog tias tooj liab tau ua tiav cov txiaj ntsig zoo ib yam los ntawm lwm txoj kev (xws li kev ua haujlwm hnyav thaum lub caij txias deformation), nws cov plasticity yuav luag ploj tag. Solid solution reinforcing yog ib txoj hauv kev ntxiv dag zog uas siv cov kev sib cuam tshuam ntawm cov atoms thiab txav dislocations nyob rau hauv cov kev daws teeb meem kom ua rau muaj kev ntxhov siab ntau ntxiv. Los ntawm kev ntxiv qhov tsim nyog ntawm cov ntsiab lus alloying rau lub hauv paus los tsim cov kev daws teeb meem, lub zog ntawm cov hlau feem ntau yuav raug txhim kho. Raws li Mott-Nabbaro txoj kev xav, rau cov kev daws teeb meem nyias, qhov kev hloov pauv ntawm lub zog tawm los nrog cov ntsiab lus ntawm cov ntsiab lus tau qhia tau hais tias: б=бo+kCm. Nyob rau hauv cov mis, б yog lub alloy yield zog; бo yog lub zog tawm los ntawm cov hlau ntshiab; C yog cov atomic loj concentration; k thiab m yog qhov tsis tu ncua txiav txim siab los ntawm cov khoom ntawm matrix thiab alloy ntsiab, qhov twg tus nqi ntawm m yog nyob nruab nrab ntawm 0.5 thiab 1.
4. Kev laus nag lossis daus (ua nag lossis daus) ntxiv dag zog
Lub hauv paus ntsiab lus ntawm lub hnub nyoog nag lossis daus ntxiv yog ntxiv cov ntsiab lus alloying rau tooj liab uas muaj cov khoom me me solubility ntawm chav tsev kub thiab cov khoom loj solubility ntawm qhov kub thiab txias. Los ntawm kev kub-kub cov khoom siv kho mob, cov khoom siv alloying tsim cov tshuaj supersaturated hauv lub hauv paus. Qhov no Lub zog yog zoo dua piv nrog cov ntshiab tooj liab. Tom qab ntawd dhau los ntawm kev laus, cov kua dej supersaturated decomposes, cov ntsiab lus alloy precipitate nyob rau hauv ib daim ntawv, thiab dispersed thiab faib nyob rau hauv lub hauv paus los ua ib tug nag lossis daus theem. Cov theem precipitated tuaj yeem tiv thaiv kev txav ntawm cov ciam teb ntawm cov qoob loo thiab kev tsis sib haum xeeb, yog li txhim kho lub zog ntawm cov hlau zoo heev. Cov ntsiab lus alloying uas tsim los nag kom muaj zog yuav tsum ua tau raws li ob qho xwm txheej hauv qab no: ua ntej, cov khoom solubility hauv tooj liab ntawm qhov kub thiab txias yog qhov sib txawv heev, yog li cov txheej txheem muaj zog txaus tuaj yeem tsim tau thaum laus; Thib ob, cov khoom solubility hauv tooj liab ntawm chav tsev kub yog qhov sib txawv heev. Lub solubility yog heev me me kom ntseeg tau siab conductivity ntawm lub matrix. Precipitation reinforcing yog siv dav siv los txhawb txoj hauv kev muaj zog, siab-conductivity tooj liab alloys. Nyob rau hauv tooj liab alloys, nyob rau hauv thiaj li yuav tsim cov laus nag lossis daus, cov ntsiab lus ntxiv xws li Ti, Co, P, Ni, Si, Mg, Cr, Zr, Be, Fe, thiab lwm yam. txhim kho lub zog ntawm cov khoom thaum txo kev puas tsuaj rau cov hluav taws xob conductivity.
5. Kev nthuav dav ntxiv
Dispersion strengthening yog ib yam khoom uas npaj los ntawm hmoov metallurgy thiab lwm txoj kev tom qab tag nrho sib tov ib tug dispersion ntxiv dag zog rau theem hmoov ntawm ib tug tej yam duab thiab loj nrog tooj liab hmoov. Qhov thib ob qhov hais (Al2O3, ThO2, Zro2, thiab lwm yam) yog dispersed thiab faib nyob rau hauv tooj liab matrix, thiab lub zog ntawm cov tooj liab alloy yog zoo dua vim lub dispersion ntxiv dag zog rau cov nyhuv. Txoj kev no tsis tshua muaj kev cuam tshuam rau hluav taws xob thiab thermal conductivity ntawm tooj liab thaum txhim kho lub zog. Yuav kom tau dispersedly faib theem ob hais nyob rau hauv tooj liab matrix, nws muaj peev xwm txiav txim siab hais tias theem ob hais ntxiv rau lub tooj liab matrix los yog dispersedly faib theem ob particles yog generated nyob rau hauv situ nyob rau hauv lub tooj liab matrix los ntawm ib tug tej yam txheej txheem. Cov txheej txheem tshwj xeeb suav nrog: txoj kev sib xyaw ua ke, txoj kev sib koom ua ke, txoj hauv kev oxidation sab hauv, rov qab gel nag lossis daus txoj kev, electrolytic nag lossis daus txheej txheem, thiab lwm yam.
(1) Lub mechanism. Thaum lub sij hawm cov yas deformation, cov kab dislocation tsis tuaj yeem txiav ncaj qha los ntawm theem thib ob particle, tab sis nyob rau hauv qhov kev txiav txim ntawm sab nraud quab yuam, cov kab dislocation tuaj yeem khoov ib ncig ntawm theem thib ob, thiab thaum kawg lub nplhaib dislocation yog sab laug nyob ib ncig ntawm theem ob particle thiab muab txoj hauv kev. . Hla dhau. Cov dabtsi yog khoov ntawm dislocations yuav ua rau kom lub lattice distortion zog nyob rau hauv lub dislocation- cuam tshuam cheeb tsam, uas ua rau kom cov kev tiv thaiv rau lub zog ntawm dislocation kab thiab ua rau kom lub pliaj kuj.
(2) (2) Ansel-Lenier mechanism. GS Ansell et al. thov lwm tus qauv dislocation rau yielding ntawm dispersion-strengthened alloys. Lawv siv qhov tawg ntawm dispersed theem ob particles vim dislocation tsub zuj zuj raws li cov txheej txheem rau yield. Thaum cov kev ntxhov siab ntawm cov khoom sib npaug sib npaug ntawm cov kev ntxhov siab ntawm cov khoom tawg, cov dispersion-strengthened alloy yields.
6. Fiber in-situ composite reinforcement
Txoj kev no feem ntau yog hais txog kev ntxiv cov khoom siv ntau dhau (Cr, Fe, V, Nb, thiab lwm yam) rau tooj liab kom tau txais ob-theem complex. Cov ntsiab lus ntau dhau muaj nyob rau hauv cov khoom sib xyaw ua ke nyob rau hauv daim ntawv ntawm ib theem thiab cov qauv dendritic. Tom qab ntawd, cov hlau yog stretched nrog ib tug loj deformation, thiaj li hais tias cov dendritic qauv ntawm cov alloy ntsiab yog hloov mus rau hauv ib tug fiber ntau qauv. Lub xub ntiag ntawm fibers tsub kom qhov tsis kam mus rau dislocation txav, yog li ntxiv dag zog rau cov khoom.
7. Ntxiv cov kab lus
Ntxiv qee cov kab hauv qab rau lub hauv paus rau alloy nws tuaj yeem tsis tsuas yog ntxiv dag zog rau cov hlau, tab sis kuj yog ib qho txiaj ntsig zoo rau kev tsim cov khoom siv corrosion-resistant. Qee qhov ntawm cov kab no ntxiv dag zog rau cov hlau los ntawm kev tsim cov theem tawg, thiab qee qhov los ntawm kev ua kom huv ntawm cov qauv matrix, tab sis tsis muaj leej twg txo nws txoj kev tiv thaiv corrosion, yog li txhim kho tag nrho cov kev ua tau zoo ntawm cov hlau.
