Copper-deposited carbon fiber aluminium ua npuas ncauj sandwich vaj huam sib luag kev ua tau zoo piv rau cov pa txhuas ua npuas ncauj sandwich vaj huam sib luag

Aluminium ua npuas ncauj sandwich(AFS) panels muaj kev sib xyaw ua ke ntawm cov qauv thiab kev ua haujlwm xws li tsis tshua muaj siab, muaj zog tshwj xeeb, muaj zog nqus dej, muaj peev xwm ua kom tsis muaj zog, thiab tiv thaiv electromagnetic. Cov khoom zoo heev no ua rau AFS muaj peev xwm zoo hauv aerospace, kev thauj mus los, thiab marine fields. Piv nrog cov hlau tsis tshua muaj hlau, cov hlau hlau sab nraud ntawm AFS tuaj yeem ua rau cov npuas dej zoo thiab txhim kho nws cov khoom siv kho tshuab, xws li tensile thiab dabtsi yog khoov zog. Feem ntau, AFS tau tsim los ntawm cov nplaum nplaum, uas txuas nrog cov txhuas ua npuas ncauj rau cov hlau nplaum uas siv epoxy resin nplaum.

Txawm hais tias cov txheej txheem nplaum nplaum ua tau zoo txhim kho cov txheej txheem damping, nws yog nrog los ntawm cov kev txwv, nrog rau cov teeb meem hauv kev rov ua dua tshiab thiab cuam tshuam rau delamination tsis ua hauj lwm nyob rau hauv high-temperature los yog corrosive tej yam kev mob. Txhawm rau daws cov kev txwv no, kev tshawb fawb dav dav tau mob siab rau kom ua tiav kev sib koom ua ke ntawm cov vaj huam sib luag thiab cov txheej txheem tseem ceeb.

Tam sim no, txoj kev npaj tseem ceeb tshaj plaws rau AFS txhawm rau ua tiav kev sib koom ua ke ntawm metallurgical feem ntau muab faib ua peb pawg: welding, yaj foaming, thiab packing dov hmoov metallurgy txoj kev. Ntawm cov txheej txheem no, packing dov hmoov metallurgy txoj kev yog suav tias yog superior rau kev tswj lub pore qauv thiab ua tau raws li qhov kub thiab txias foaming. Peb cov hauj lwm yav dhau los tau siv cov thev naus laus zis no los tsim cov AFS loj loj nrog cov khoom nthuav dav zoo dua thiab cov qauv ntawm tes rau cov ntawv thov kev lag luam.

Txawm li cas los xij, vim qhov tsis tshua muaj compressive mechanical zog ntawm cov tub ntxhais ua npuas ncauj, kev txhim kho ntawm lub zog ntawm AFS yog txwv, yog li kev txhim kho ntxiv ntawm lub zog ntawm cov tub ntxhais ua npuas ncauj yog qhov tseem ceeb rau AFS.

Txog rau hnub tim, cov txheej txheem tau tshaj tawm los txhim kho cov khoom siv tshuab compressive ntawmaluminium ua npuas ncaujCov nram qab no: kev kho deg, kev kho cua sov, thiab kev txhawb zog los ntawm kev ntxiv cov khoom, fibers, alloying ntsiab, thiab lwm yam. Ntawm lawv, luv carbon fibers nrog tsawg ntom, siab elastic modulus, thiab loj nam piv tau attracted dav xim raws li cog lus txhawb cov ntaub ntawv. Ntxiv mus, deg metallization ntawm carbon fibers, los ntawm electroplating los yog tshuaj plating xws li tooj liab plating los yog npib tsib xee plating, ntxiv txhim kho lub wettability ntawm cov carbon fibers nyob rau hauv lub txhuas yaj thiab tsis txhob muaj teeb meem interfacial tshwm sim ntawm cov carbon fibers thiab txhuas yaj. Cov pa roj carbon fiber luv yog tam sim no dav siv los txhawb cov txhuas matrix composites.

Bhav Singhetal. npaj tooj liab-coated carbon fibers reinforced aluminium matrix composites los ntawm do casting txoj kev. Muetal. fabricated aluminium matrix composites txhawb nrog nickel-coated carbon fibers siv ob-yob casting txoj kev. Cov txiaj ntsig tau pom tias muaj kev txhim kho tseem ceeb hauv lub zog tensile ntawm cov khoom sib xyaw nrog ntxiv ntawm carbon fibers. Txawm li cas los xij, muaj qee qhov kev tshawb fawb tau ua raualuminium ua npuas ncauj reinforcednrog tooj liab-coated carbon fibers. Caoetal. thawj npaj tooj liab-coated carbon fibers reinforced txhuas ua npuas ncauj los ntawm cov yaj foaming txoj kev. Cov txiaj ntsig tau pom tias 0.35 vol% ntawm Cf tuaj yeem ua kom ruaj khov ntawm cov txhuas ua npuas ncauj los ntawm kev tiv thaiv cov yeeb yaj kiab ua kua, thiab qhov ntau ntawm cov fibers ntxiv rau hauv npuas yog ruaj khov dua. Muetal. qhia tau hais tias cov khoom damping ntawm txhuas ua npuas ncauj npaj los ntawm cov yaj foaming txoj kev tau zoo heev nrog ntxiv ntawm Cf.

Raws li, nws tuaj yeem txiav txim siab tias qhov sib ntxiv ntawm Cf tuaj yeem yog lub tswv yim zoo los txhim kho cov foaming stability thiab txhua yam khoom ntawmaluminium foams. Tsis tas li ntawd, tsis muaj cov ntaub ntawv qhia txog tooj liab-plated carbon fibers reinforced aluminium foam sandwich panels npaj los ntawm cov hmoov metallurgy txoj kev, uas txhawb cov kws tshawb fawb los ua kom muaj kev tshawb fawb ntau ntxiv hauv daim teb no.

Ntau cov kev tshawb fawb tau ua tiav ntawm nucleation mechanism thiab stability ntawmaluminium foamsnrog rau qhov sib ntxiv ntawm cov theem reinforcing. Qhov sib txawv ntawm pore naj npawb thiab pore morphology,

xws li qhov loj me, kev faib tawm, thiab cov duab, feem ntau yog los ntawm nucleation mechanisms thiab stability. Heterogeneous nucleation teebmeem thiab oxide network stabilization mechanisms hauv hmoov metallurgy system tau raug tshawb xyuas tag nrho. Quaternary alloy hmoov uas muaj Al-Si-Mg-Cu siv hauv daim ntawv no tau nthuav tawm qhov tshwj xeeb nthuav dav thiab qis foaming kub, nrog rau qhov kub thiab txias ntawm 507 ◦C thiab cov kua dej kub ntawm 596 ◦C. Txawm li cas los xij, tsis muaj kev tshawb fawb txog nucleation mechanism, stability, thiab compressive mechanical zog ntawm cov hmoov compacts uas muaj qhov tshwj xeeb alloy muaj pes tsawg leeg, tshwj xeeb tshaj yog thaum koom nrog Cf. Hauv kev ua haujlwm yav dhau los, kev tshawb nrhiav ntawm nucleation thiab stabilization mechanisms feem ntau yog ua los ntawm cov txheej txheem tsis nyob hauv qhov chaw, suav nrog tomographic tsom xam ntawm cov qauv uas tau txias sai sai tom qab foaming cuam tshuam. Hmoov tsis zoo, submicron npuas nucleation feem ntau tshwm sim thaum lub sij hawm ua ntej cua sov thiab nthuav tawm sai sai nyob rau hauv lub sij hawm luv luv ntawm 100 ms mus rau 1 s, feem ntau nthuav tawm cov teeb meem rau kev soj ntsuam lub sij hawm. Cov txheej txheem niaj hnub synchrotron hluav taws xob X-ray imaging txheej txheem muaj lub zog siab thiab kev daws teeb meem spatiotemporal, tso cai rau lub sijhawm tiag tiag, nyob rau hauv qhov kev soj ntsuam ntawm nucleation thiab kev loj hlob ntawm aluminium foams ntawm qhov kub thiab txias. Tam sim no, tsuas yog cov kws tshawb fawb txwv tau tshawb nrhiav cov foaming kinetics ntawm Al-Si-Mg alloy hmoov los ntawm hluav taws xob synchrotron. Piv txwv li, García-Morenoetal. qhia txog qhov tseem ceeb dynamic phenomena nyob rau hauv cov kua txhuas ua npuas ncauj, nrog rau nucleation thiab kev loj hlob, npuas rearrangement, kua retraction, agglomeration, thiab zaj duab xis rupture. Kam et al. tau kawm txog cov txheej txheem nucleation thiab kev loj hlob ntawm AlSi8Mg4 txhuas ua npuas ncauj los ntawm hluav taws xob synchrotron. Lawv qhov kev tshawb pom tau qhia tias hydrogen generated los ntawm decomposition ntawm adsorbates ntawm cov hmoov hlau saum npoo sawv cev rau lwm qhov tseem ceeb nucleation mechanism. Txawm li cas los xij, kev sib cuam tshuam ntawm cov khoom ua ntej yog qhov sib txawv, thiab qhov kev ua kom muaj zog ntawm foaming tuaj yeem cuam tshuam los ntawm lawv cov muaj pes tsawg leeg. Rau ob qho tib si Al-Si-Cu-Mg hmoov system thiab Al-Si-Cu-Mg hmoov system nrog ntxiv Cf, kev nkag siab thiab tshawb nrhiav qhov pib thiab kev loj hlob ntawm cov hlau ua npuas ncauj yog qhov tseem ceeb rau kev txhim kho cov txheej txheem ntxiv ntawm cov npuas dej los txhim kho cov khoom. rau daim ntawv thov.

Hauv kev ua haujlwm no, Cf / AFS thiab AFS nrog metallurgical interfacial bonding tau npaj los ntawm packing dov hmoov metallurgy txoj kev. Cov npuas evolution ntawm Cf / AFS thiab AFS tau pom nyob rau hauv qhov chaw los ntawm cov hluav taws xob synchrotron los qhia cov txheej txheem ntawm Cf ntawm npuas nucleation, kev loj hlob thiab kev sib koom ua ke, thiab kev ruaj ntseg. Tsis tas li ntawd, Cf/AFS thiab AFS tau foamed ntawm 620 ◦C rau 15 min nyob rau hauv lub chamber furnace. Tom qab ntawd, qhov pore loj faib, pore microstructure, thiab compressive mechanical zog ntawm cov qauv foamed tau pom thiab kuaj. Raws li cov kev tshawb fawb saum toj no, cov qauv thiab lub zog compressive ntawm Cf / AFS thiab AFS tau raug soj ntsuam zoo.

2. Cov ntaub ntawv thiab cov txheej txheem

2.1. Cov khoom nyoos

Rau cov khoom siv raw tau siv rau kev npaj AFS thiab Cf / AFS: Al hmoov (qhov nruab nrab loj: 45 μm, purity> 99.70%), Si hmoov (qhov nruab nrab loj: 38 μm, purity> 99.50%), Cu hmoov (qhov nruab nrab loj: 38 μm, purity> 99.90%), Mg hmoov (qhov nruab nrab loj: 75 μm, purity) > 99.70%), TiH2 hmoov (qhov nruab nrab loj: 45 μm, purity> 99.70%), thiab tooj liab-coated carbon fiber (qhov nruab nrab loj: 1 ~ 2 hli, thickness ntawm tooj liab-coated: 1.4 μm).

2.2. Fabrication ntawm Cf/AFS

Lub schematic ntawm packing dov hmoov metallurgy txoj kev yog illustrated nyob rau hauvFig. 1. Thaum lub sij hawm sib tov, cov quaternary alloy AlSi6Mg4Cu4 hmoov tau npaj, nrog cov hmoov Al, Si, Cu, thiab Mg nyob rau hauv proportions ntawm 86 wt%, 6 wt%, 4 wt%, thiab 4 wt%, feem. 1 wt% oxidized TiH2 hmoov (kev kho cua sov hauv huab cua rau 1.5 teev ntawm 470 ◦C) tau ntxiv los ua tus neeg sawv cev tshuab uas tso tawm H2 sai sai ntawm qhov kub thiab txias nthuav tawm cov yaj. Tsis tas li ntawd, 0.5 wt% ntawm cov pa roj carbon fibers tau muab tso ua ke raws li theem kev txhawb zog. Qhov tseem ceeb, txhawm rau txhim kho kev ntub dej thiab tiv thaiv kev puas tsuaj xws li Al4C3 ntawm fiber-aluminium melt interface thaum foaming, carbon fibers tau tooj liab-coated ntawm electroplating. Cov txheej txheem electroplating tau piav qhia hauv Refs.Daim duab 2qhia txog tooj liab-coated carbon fibers tau los ntawm cov txheej txheem electroless plating. Cov txheej txheej muaj qhov sib xws thiab txuas txuas ntxiv ntawm fiber ntau nto(Fig. 2(a)–(b)). Tom qab ntawd, qhov sib txawv ntawm cov khoom siv sib txawv siv hauv txoj kev tshawb no tau npaj los ntawm kev sib xyaw ua ke ntawm cov hmoov uas tau hais tseg saum toj no nrog thiab tsis muaj Cf hauv peb qhov sib tov rau 3 teev. Cov hmoov sib tov sib xyaw ua ke yog ntim rau hauv cov kab noj hniav kaw, ua raws li cov txheej txheem txias thiab kub dov.

Lub caij txias dov tau zoo tshem tawm huab cua los ntawm cov kab noj hniav thiab qhov chaw nruab nrab ntawm cov khoom los ntawm ntau qhov kev hla thiab kev nyuaj siab me me. Qhov kub dov theem ua kom ntseeg tau tias cov khoom ua ntej ua tiav qhov sib txheeb ze tshaj 98% los ntawm kev sib koom ua ke ntawm lub vaj huam sib luag thiab hmoov, uas ua rau cov txheej txheem foaming tom ntej. Cov txheej txheem dov kom ntxaws tau piav qhia hauv Refs. AFS thiab Cf / AFS foamable precursors tau txais los ntawm cov txheej txheem saum toj no. Thaum kawg, ob qho tib si foamable precursors tau rhuab ntawm 620 ◦C rau 15 min los fabricate Cf/AFS thiab AFS specimens, uas tau siv rau pore loj tsom xam, microstructural characterization, thiab compressive mechanical zog kuaj.

2.3. Cov yam ntxwv thiab cov txheej txheem xeem

2.3.1. Microstructural characterization

Lub microstructure morphology ntawm Cf / AFS thiab AFS tau tshawb xyuas los ntawm qhov chaw emission scanning electron microscopy (SEM, Zeiss Ultra Plus). Lub zog dispersive spectroscopy (EDS) tau siv los txheeb xyuas qhov muaj pes tsawg leeg ntawm ntau theem hauv cov phab ntsa ntawm tes ntawm cov qauv foamed. Cov ntu ntev ntawm cov qauv tau txais los ntawm kev txiav cov qauv foamed siv lub tshuab electro-discharging (EDM, DK7745). Ua raws li qhov no, cov qauv 'ntev ntu tau coated nrog cov xim thiab tom qab ntawd sanded thiab polished siv 800-grit thiab 1500-grit sandpaper, feem. Thaum kawg, qhov sib npaug ntawm tes diameters (Dmean) ntawm cov qauv polished hla ntu tau txiav txim siab siv cov duab tsom xam software, Image Pro Plus 6.0.

Fig. 1.Schematic ntawm packing dov hmoov metallurgy txoj kev.

Daim duab 2.SEM cov duab ntawm (a) tooj liab-coated carbon fibers, thiab (b) qhia pom qhov loj ntawm thaj av uas cim los ntawm lub square liab hauv (a). Cov duab (c) thiab (d) yog EDS cov txiaj ntsig ntawm qhov point A hauv (b).

Fig. 3.Schematic daim duab ntawm lub synchrotron hluav taws xob sim teeb.

2.3.2. Nyob rau hauv-situ foaming soj ntsuam los ntawm synchrotron hluav taws xob

Lub schematic daim duab ntawm lub synchrotron hluav taws xob sim teeb yog sketched nyob rau hauvFig. 3. Cov kev sim tau ua nyob rau ntawm beamline 4W1A ntawm Beijing Synchrotron Radiation Facility (BSRF, Beijing Institute of High Energy Physics, Suav Academy of Sciences, Suav). Tsis zoo li cov qauv kev nqus-zoo sib xws, daim ntawv no siv cov duab sib piv nrog Synchrotron Radiation Light Source. Txoj hauv kev no hais txog cov kev txwv ntawm kev nqus cov duab ib txwm muaj, uas tsis muaj txiaj ntsig rau kev pom cov khoom tsis muaj zog. Cov txheej txheem foaming ntawm cov hnoos qeev tau ua nyob rau hauv lub qhov cub ua npuas ncauj, uas muaj 15 hli los ntawm 15 hli square qhov rais positioned perpendicular mus rau X-ray beam kev taw qhia. Cov qauv loj, raws li tau piav qhia hauv daim duab 3, ntsuas 15 hli × 15 hli × 2 hli. Cov qauv yog muab tso rau hauv ib lub pwm foaming uas muaj qee yam ntawm cov ntawv ceramic. Thoob plaws hauv cov txheej txheem foaming, X-rays tuaj yeem dhau los ntawm cov qauv thiab raug ntes los ntawm lub koob yees duab charge-coupled device (CCD). Kev xaiv X-ray qhov chaw ua haujlwm ntawm qhov kev siv ntawm 20 Kev, thiab qhov pom qhov siab tshaj plaws ntawm 7.4 mm × 7.4 mm tau ua haujlwm los ua kom pom kev pom ntawm tag nrho cov txheej txheem foaming.

Nws yog tsim nyog sau cia tias cov qauv pom tau muab tso rau hauv ib qho kev perpendicular rau ob qho tib si dov kev taw qhia thiab tangential kev taw qhia. Ob lub precursors uas muaj 0.5 wt% Cf thiab cov uas tsis muaj 0.5 wt% Cf tau lawv sab panels tshem tawm ntawm ob sab ntawm cov qauv siv EDM. Cov nyhuv ntawm Cf ntawm cov yam ntxwv foaming ntawm txhuas ua npuas ncauj tau tshawb xyuas. Tsis tas li ntawd, cov precursors nrog sib txawv compositions tau foamed nyob rau hauv tib lub cua sov rauv ntawm ib tug preset kub ntawm 620 ◦C.

2.3.3. Compression mechanical properties test

Cov qauv compression raug txiav rau hauv cov qauv cylindrical nrog qhov siab ntawm 23 hli thiab txoj kab uas hla ntawm 20 hli los ntawm EDM, thiab txhua qhov kev taw qhia tau ua kom muaj qhov tsawg kawg nkaus 10 qhov pores kom tsis txhob muaj qhov loj me. Quasi-static compression tests tau ua raws li cov qauv ISO13314-2011 thiab GB / T31930-2015, siv AG-XPLUS electron universal khoom kuaj tshuab nrog lub peev xwm siab tshaj plaws ntawm 100 KN. Peb cov qauv raug sim rau txhua pab pawg, thiab cov qauv kev ntxhov siab-kev nyuaj siab hauv daim ntawv no sawv cev rau qhov nruab nrab cov txiaj ntsig tau los ntawm peb cov qauv kuaj. Tag nrho cov kev ntsuam xyuas tau ua nyob rau hauv kev tswj kev txav chaw, tswj qhov kev sib tw ntawm lub taub hau tas li ntawm 2 mm / min (raws li qhov kev sib tw thawj zaug ntawm 10- 3 s- 1) ntawm chav tsev kub.

Daim duab 4.Lub sij hawm-evolved synchrotron hluav taws xob cov duab ntawm Cf / AFS foaming txheej txheem: (a) unfoamed precursor ntawm t0 lub sij hawm ntawm 380 ◦C; (b) – (c) dissolution ntawm elemental tooj liab thiab hom II nucleation thaum lub sij hawm precursor melting; (d)–(g) heterogeneous nucleation thiab kev loj hlob ntawm npuas; thiab (h)–(i) npuas sib koom ua ke thiab rupture.

3. Cov txiaj ntsig thiab kev sib tham

3.1. Nyob rau hauv situ foaming cwj pwm nyob rau hauv synchrotron hluav taws xob

3.1.1. Ua npuas ncauj evolution ntawm Cf/AFS

Daim duab 4qhia txog cov duab ntawm cov duab hluav taws xob synchrotron uas piav txog cov txheej txheem foaming ntawm Cf/AFS. Cov duab qub ntawm Cf/AFS(Fig. 4 (a))raug ntes thaum lub matrix nyob rau hauv lub xeev ntawm 380 ◦C, thiab lub sij hawm no tau teem li t0. Piv nrog rau lwm cov khoom nyob rau hauv precursor, Cf zoo nkaus li dub nyob rau hauv lub feem ntau grey txhuas-nplua nuj matrix. Qhov no tuaj yeem raug ntaus nqi rau cov ntsiab lus tooj liab siab ntawm fiber ntau, raws li qhia hauvDaim duab 2(c)–(d), uas muaj qhov loj tshaj plaws txheeb ze atomic huab hwm coj piv rau lwm yam khoom ntawm lub precursor. Tsis tas li ntawd, feem ntau ntawm Cf raug soj ntsuam kom sib cais thiab cais, tsis yog pawg ua ke, raws li tau nthuav tawm hauvDaim duab 4(a). Qhov no txhais tau hais tias nrog 0.5 wt% ntxiv ntawm Cf, 3 h stirring txheej txheem tuaj yeem ua tiav qhov xav tau ntawm kev tawg.

Ntawm t0 + 194s (raws li pom hauvDaim duab 4 (b)), muaj ntau ntau ntawm cov dawb, ze li ntawm kheej kheej npuas nrog diameters li ntawm 90 μm mus rau 180 μm tuaj yeem pom hauv grey aluminium matrix (cim nrog lub xub liab). Tus naj npawb ntawm npuas txuas ntxiv nce hauv 46 s, raws li qhia hauvDaim duab 4 (c). Tsis tas li ntawd, lwm qhov kev hloov pauv tseem ceeb tshwm sim hauv matrix yog tias qee cov npuas me me yuav tsim rau ntawm Cf nrog qhov pib ntawm Cu dissolutions (cim nrog lub thawv liab dotted). Qhov tshwm sim no yuav tshwm sim los ntawm hom II nucleation tshwm sim hauv cov hmoov tooj liab uas muaj cov hmoov sib tov. Nws yog dav lees paub tias qhov sib ntxiv ntawm Cu txo qis qhov kub ntawm cov alloys. Qhov no ua rau hauv ib cheeb tsam melting nyob ib ncig ntawm ib tug neeg hmoov hais nyob rau hauv cov hmoov precursor uas muaj tooj liab hmoov thaum lub sij hawm cua sov txheej txheem, tsim ib tug ntau npaum li cas ntawm Al-Si-Mg-Cu quaternary eutectic yaj ntawm qis kub. Lub pas dej quaternary eutectic melts zoo li ib cheeb tsam uas tsis muaj zog nyob rau hauv cov hlau thiab yog ntau dua rau nucleation. Yog li ntawd, npuas yuav ntau dua nucleate thiab loj hlob ze ntawm tooj liab-coated ntawm fiber ntau. Tsis tas li ntawd, cov kua qis qis hauv cov matrix ntawm lub sijhawm no ua rau cov pa roj los ntawm qhov decomposition ntawm TiH2 kom yooj yim sau rau hauv cov txhuas matrix. Hom II nucleation tuaj yeem zam tau cov roj sib xyaw ua kom cov kua qis qis matrix sib nrug thiab nthuav tawm cov kab nrib pleb los ntawm cov kua, uas ua rau poob loj ntawm cov hydrogen.

Daim duab 4(d)qhia tau hais tias cov npuas pib nucleate thiab loj hlob nyob rau thaj tsam ntawm Cf raws li cov matrix tag nrho melts, thiab cov npuas qhov chaw sib raug rau cov txheej tooj liab-coated ploj (cim nrog lub thawv liab dotted). Nws yog qhov zoo-tsim tias qhov sib ntxiv ntawm cov theem ob ua rau muaj ntau qhov chaw nucleation heterogeneous, yog li txo lub zog thaiv rau kev tsim cov npuas tshiab hauv cov hlau yaj. Lub caij no, tus nqi nucleation muaj feem xyuam rau tag nrho heterogeneous nucleation cheeb tsam ib chav tsev ntim. Yog li ntawd, nws tuaj yeem pom tias cov npuas pib pib nucleate ntawm qhov chaw uas carbon fibers nyob thiab nthuav dav raws qhov ntev ntawm carbon fiber. Nrog rau qhov nce ntxiv ntawm cov yaj feem ntau, ntau cov npuas tshiab txuas ntxiv los ntawmFig. 4(e)–4(g). Txawm li cas los xij, tus nqi ntawm kev sib koom ua ke hauv zos thiab kev tawg ntawm cov npuas yog qeeb, qhia tias cov npuas muaj kev ruaj ntseg siab. Ntawm t0 + 426s, tus naj npawb ntawm npuas nce ntau, thiab

lub precursor ntim nthuav dav loj(Fig. 4(h)). Tsis tas li ntawd, qhov tshwm sim ntawm qee cov npuas sib koom ua ke (cim nrog cov xub liab), qhov twg cov npuas me me tau nqus los ntawm cov loj dua vim Ostwald maturation, yog ib qho kev inevitable thaum lub sij hawm evolution ntawm metallic foams [40]. Qhov no maturation tshwm sim kuj ua rau cov tsos ntawm ib tug me me ntawm cov loj thiab irregular npuas (cim nrog lub liab xub nyob rau hauvDaim duab 4 (i)).

Daim duab 5.Lub sij hawm-evolved dluab ntawm cov txheej txheem foaming ntawm AFS ntawm ntau theem: (a) unmelted precursor ntawm t0 lub sij hawm ntawm 380 ◦C; (b) dissolution ntawm elemental tooj liab thiab hom II nucleation thaum lub sij hawm precursor melting; (c) nucleation thiab kev loj hlob ntawm cov npuas; thiab (d)–(f) npuas sib xyaw thiab rupture.

3.1.2. Ua npuas ncauj evolution ntawm AFS

Daim duab 5 qhia tau hais tias cov duab ntawm cov duab hluav taws xob synchrotron qhia txog cov txheej txheem foaming ntawm AFS. Zoo ib yam li Cf/AFS, thawj daim duab rau cov kab hluav taws xob synchrotron raug ntes thaum AFS nyob rau theem khoom ntawm 380 ◦C (saibDaim duab 5(a)). Thaum lub matrix yog rhuab saum lub solidus kub, me npuas dawb ua pom nyob rau hauvDaim duab 5(b) thiab (c), uas tshwm sim los ntawm decomposition ntawm TiH2 thiab tshwm sim ntawm hom II nucleation nyob rau hauv lub Cu-nplua nuj cheeb tsam. Txawm li cas los xij, tus naj npawb ntawm cov npuas tsim tawm thiab lawv qhov kev faib tawm ceev hauvDaim duab 5 (c)yog notably qis dua piv rauDaim duab 4 (c). Qhov no qhia tias Cf / AFS muab ntau txoj hauv kev rau kev tso pa tawm thaum ntxov thaum lub sijhawm nucleation, tiv thaiv qhov ntau dhau rau-mation ntawm cov kab nrib pleb hauv aluminium matrix nrog cov kua dej tsawg.

Tsawg tus naj npawb ntawm AFS nucleation qhov chaw thiab qhov tshwm sim ntau dua ntawm kev loj hlob ntawm cov npuas tsis zoo piv rau Cf / AFS tuaj yeem pom los ntawmFig. 5(d)–(f). Cov evolution ntawm AFS npuas yog tsis xwm yeem, thiab lawv qhov ntau thiab tsawg nthuav dav qhov hloov pauv vim yog kev sib koom ua ke ntawm ob qho tib si micrometer npuas npuas thiab txawv txav millimeter-loj npuas loj (cim nrog lub xub liab). Ntxiv mus, qhov kev tsis sib haum xeeb thiab tsis sib haum xeeb thaum lub sij hawm cov txheej txheem nucleation thaum ntxov tuaj yeem ua rau muaj qhov sib txawv tseem ceeb hauv qhov kawg pore qauv thiab cov khoom siv tshuab ntawm AFS thiab Cf / AFS.

3.2. Kev tsom xam macrostructure

Txhawm rau tshawb xyuas qhov sib txawv ntawm macroscopic pore morphology thiab pore txoj kab uas hla ntawm AFS thiab Cf / AFS, ob lub sandwich vaj huam sib luag tau npaj nyob rau hauv qhov chaw kuaj mob ntawm qhov kub thiab txias ntawm 620 ◦C rau 15 min. Cov macrostructures thiab cell loj faib ntawm AFS thiab Cf/AFS tau qhia hauvDaim duab 6. Kev sib piv ntawm cov ntu ntsug ntawm ob lub qauv sandwich qauv qhia tau hais tias Cf / AFS foams muaj cov hlwb zoo dua thiab muaj qhov tsis xws luag xws li kev tawg lossis kev sib koom ua ke ntawm cov hlwb (saibDaim duab 6 (b)). Ntawm qhov tsis sib xws, raws li qhia hauvDaim duab 6(a), AFS nthuav tawm cov pore homogeneity tsis zoo nrog rau qhov muaj qee qhov txawv txav loj. Lub caij no, qhov sib npaug pore txoj kab uas hla rau AFS thiab Cf / AFS yog 2.9 ± 0.2 mm thiab 1.9 ± 0.1 mm, ntsig txog, qhia tias lub pore txoj kab uas hla yog ntxiv refined los ntawm qhov sib ntxiv ntawm Cf (saibDaim duab 6 (c) thiab (d)).

Lub evolution ntawm lub pore qauv yog cuam tshuam los ntawm ob qho kev sib tw mechanisms: lub decomposition ntawm TiH2 thiab cov merging thiab rupture ntawm cov npuas. Lub decomposition ntawm TiH2 pab txhawb rau qhov nce ntawm cov nucleation, porosity, thiab expansion npaum li cas, thaum lub merging thiab rupture ntawm npuas yuav txo tus naj npawb ntawm pores thiab nce lub cheeb ntawm lub pores. Kev txo cov npuas sib xyaw ua ke thiab cov xwm txheej tawg ua rau kom tau txais cov qauv cellular zoo dua. Yog li ntawd, lub siab ruaj khov ntawm cov npuas dej yog tsim nyog los tuav lub homogeneity ntawm lub pore qauv thaum lub sij hawm foaming txheej txheem. Rau Cf / AFS, qhov sib ntxiv ntawm Cf zoo heev txhim kho cov wettability ntawm fibers nrog aluminium yaj. Zoo ib yam li cov lus tshaj tawm Cf reinforced aluminium ua npuas ncauj [44] npaj los ntawm cov txheej txheem yaj foaming, qhov sib ntxiv ntawm Cf stabilizes aluminium npuas los ntawm kev tiv thaiv cell phab ntsa tawg thiab txo agglomeration. Lub caij no, Cf tuaj yeem tsim cov qauv zoo li hauv cov phab ntsa ntawm tes, uas ua rau muaj kev sib cais quab yuam thiab tiv thaiv kev tawg ntawm npuas, yog li, txhim kho cov qauv ntawm tes, ua npuas ncauj ruaj khov, thiab kev sib txig ntawm qhov pore faib.

3.3. Microstructural characterization

Daim duab 7(a)qhia txog microstructure ntawm phab ntsa cell tom qab foaming nrog AFS. Raws li tau tshaj tawm rau AlSi6Cu4Mg4 alloy foams, eutectic Al-Si, Mg2Si, Al2Cu, thiab Al5Cu2Mg8Si6, muaj nyob rau hauv cov hlau, uas yog pom zoo nrog cov kev tshawb pom tau los ntawm EDS tsom xam hauvDaim duab 7 (b). Cov theem nkig no txo ​​cov khoom siv hluav taws xob ntawm txhuas ua npuas ncauj los ntawm kev ua kom lub qhov pore phab ntsa tsis muaj zog los yog ua raws li cov khoom tawg thaum lub sij hawm deformation. Yog li ntawd, kev txhim kho cov cuab yeej cuab tam ntawm phab ntsa pore los ntawm kev sib ntxiv ntawm cov theem txhawb zog yog ib lub tswv yim zoo thiab muaj txiaj ntsig.

Rau Cf / AFS, nws tuaj yeem pom los ntawmDaim duab 7 (c) thiab (d)tias Cf tau muab faib rau hauv phab ntsa ntawm tes lossis ntawm ntug ntawm phab ntsa ntawm tes, qhia tias Cf muaj cov dej ntub zoo heev nrog cov txhuas yaj. Tsis tas li ntawd, nws tseem ceeb heev (saib rauDaim duab 7(d)) uas ib qho me me ntawm theem precipitated Al2Cu cov ntaub ntawv ntawm qhov sib cuam tshuam ntawm fibers thiab aluminium yaj. Qhov tshwm sim no ua rau kom ua tiav kev sib raug zoo ntawm cov fibers thiab matrix. Qhov kev loj hlob ntawm cov tshuaj tiv thaiv diffusion no tuaj yeem pom nyob rau hauv intuitivelyDaim duab 4(a)–(c). Nco ntsoov tias, theem precipitated tsis tag ib puag ncig cov pa roj carbon fibers, thiab lub xeev thiab tus nqi ntawm qhov kev faib tawm no tau txais txiaj ntsig zoo rau Cf / AFS. Raws li kev tshawb fawb ntawm Lv li al, ntawm Cf reinforced aluminium matrix composite cov ntaub ntawv, nws tau pom tias qhov tsim nyog tus nqi ntawm precipitated theem tuaj yeem cuam tshuam thiab tswj lub zog interfacial daim ntawv cog lus.

Daim duab 6.Vertical seem ntawm tus qauv qauv (a) AFS thiab (b) Cf/AFS. Qhov sib npaug ntawm txoj kab uas hla piv rau thaj tsam feem ntawm cov phiaj xwm sib thooj rau (a) thiab (b) tau piav qhia hauv (c) thiab (d), feem. Cov kab nrib pleb nyob rau hauv (c) thiab (d) sawv cev rau lub log-zoo li qub. Regression (R2) sawv cev rau qhov zoo ntawm kev haum.

Daim duab 7.SEM cov duab (a) thiab (b) qhia cov microstructures sib raug rauDaim duab 6(a) AFS thiabDaim duab 6(b) Cf/AFS, feem, ntxiv,Daim duab 7(b) thiab (d) qhia thaj chaw magnifications ntawmDaim duab 7(a) thiab (c), feem.

3.4. Mechanism ntawm Cf stabilizing Al-Si-Mg-Cu ua npuas ncauj

Raws li kev soj ntsuam saum toj no, ib qho kev sawv cev ntawm lub tshuab ua npuas ncauj rau Cf / AFS thiab AFS tau sau tseg hauvDaim duab 8. Qhov sib txawv tseem ceeb ntawm Cf/AFS thiab AFS nyob rau hauv lub nucleation theem, npuas loj hlob, thiab merging theem, thiab gradual solidification theem, raws li qhia nyob rau hauvDaim duab 8(a) thiab (b).

Daim duab 8.Schematic daim duab ntawm Cf/AFS thiab AFS foaming cwj pwm: (a) Cf/AFS; thiab (b) AFS.

Nyob rau theem nucleation ntawm AlSi6Cu4Mg4 alloy foams, npuas zoo li nucleate nyob rau hauv cov kua quaternary eutectic nyob ib ncig ntawm cov tooj liab hais, es tsis nucleate ntawm qhov chaw ntawm TiH2 hais. Hom nucleation no nyob rau hauv cheeb tsam uas tsis muaj zog tshaj plaws ntawm precursor (hom II nucleation) muab ntau txoj kev khiav tawm rau cov gases tso tawm los ntawm TiH2 decomposition, zam lub tsub zuj zuj ntawm gases thiab ua rau tawg mus rau propagate nyob rau hauv lub txhuas yaj. Qhov sib ntxiv ntawm tooj liab-coated carbon fibers pom tau ntxiv tsim ntau txoj kev tso tawm H2. Txawm li cas los xij, txij li cov txhuas yaj tsis muaj cov kua dej txaus nyob rau theem no, nws nyuaj rau cov npuas me me kom muaj qhov txaus ntawm H2 kom loj hlob ntxiv. Yog li ntawd, cov npuas me me no tawg nyob rau hauv lub yaj thaum kub nce. Thaum lub precursor yog melted kiag li, lub H2 tso tawm los ntawm nruj dehydrogenation cov tshuaj tiv thaiv ntawm TiH2 yuav nucleate thiab loj hlob sai raws li nucleation point. Lub Cf muab ntau qhov chaw nucleation heterogeneous rau tiam ntawm npuas, uas ua rau kom cov nqi nucleation zoo heev. Ib txhij, lub xub ntiag ntawm Cf zoo inhibits kev sib cuag thiab kev sib koom ua ke ntawm thawj npuas thiab zam qhov tsim ntawm anomalously loj npuas.

Thaum lub sij hawm kev loj hlob thiab kev sib koom ua ke ntawm cov npuas, qhov sib ntxiv ntawm Cf ua rau muaj txiaj ntsig zoo ntawm kev ua npuas ncauj. Qhov laj thawj yog vim li cas Cf thiab txhuas yaj muaj qhov ntub dej zoo, thiab cov fibers tuaj yeem nkag tau yooj yim ntawm ob lub roj-kua sib cuam tshuam los tsim cov qauv network (raws li qhia hauvDaim duab 7 (c)). Raws li cov yeeb yaj kiab ua kua yog thinned, cov fibers tuaj yeem tsim kom muaj kev sib cais los tiv thaiv kev nqus los ntawm cov ciam teb toj siab, yog li tiv thaiv cov kua zaj duab xis los ntawm rupturing. Yog li Cf / AFS xav tau lub sijhawm ua npuas ntev dua piv rau AFS, nrog kev ruaj ntseg siab dua uas tuaj yeem tswj tau qhov sib xws ntawm cov qauv pore thaum lub sijhawm hloov pauv ntawm cov npuas dej.

Thaum lub sij hawm qeeb qeeb, npuas hauv Cf / AFS tsis loj hlob ntxiv lawm thiab cov fibers tau kos rau hauv phab ntsa ntawm tes (cim nrog lub thawv liab dotted). Qhov tuav ntawm fibers no tiv thaiv kev nqus ntawm cov npuas me los ntawm cov loj, raws li pom nyob rau hauv Ostwald maturation, thiab inhibits cell phab ntsa tawg vim solidification expansion. Raws li qhov tshwm sim, Cf / AFS nthuav tawm cov qauv pore ntau homogeneous thiab tsawg dua pore tsis xws luag piv rau AFS.

3.5. Mechanical zog

Lub compressive stress-strain curves rau Cf / AFS thiab AFS nrog yuav luag tib lub porosity (83.2% thiab 81.4%, feem) tau nthuav tawm hauvDaim duab 9(a). Lub compressive stress-strain nkhaus qhia ib tug yam ntxwv peb theem, muaj xws li linear elastic cheeb tsam, toj siab cheeb tsam, thiab densification cheeb tsam. Lub zog tawm los ntawm AFS thiab Cf / AFS yog 8.44 MPa thiab 11.87 MPa, feem. Lub zog tawm los ntawm Cf / AFS tau nce 40.6% piv rau AFS. Lub caij no, lub zog nqus peev xwm ntawm Cf / AFS zoo dua li ntawm AFS ntawm tib hom, raws li qhia hauvDaim duab 9 (b). Lub zog nqus peev xwm ntawm AFS thiab Cf / AFS yog kwv yees li 3.3 MJ / m3 thiab 6.1 MJ / m3, feem. Lub zog nqus peev xwm ntawm Cf / AFS tau txhim kho los ntawm 84.8% piv nrog AFS.

Daim duab 9.Compressive stress-train curves thiab zog absorption peev curves ntawm Cf/AFS thiab AFS: (a) compressive stress-train curves; (b) zog nqus peev xwm nkhaus.

Kev koom ua ke ntawm Cf tau txhim kho cov cuab yeej cuab tam ntawm cov tub ntxhais ua npuas ncauj. Nws yog qhov paub zoo tias cov khoom siv kho tshuab ntawmaluminium ua npuas ncaujyog ze ze rau cov qauv pore thiab strut mechanical zog. Kev tshuaj xyuas Macrostructural qhia tias qhov sib ntxiv ntawm Cf ua kom zoo dua qhov pore loj, txhim kho pore faib, thiab txo qhov pore tsis xws luag. Zoo ib yam li qhov kev tshawb pom ntawm Sasikumar et al. thiab Yangetal. me me pore txoj kab uas hla thiab nqaim pore tis muaj txiaj ntsig zoo los txhim kho lub zog compressive thiab lub zog nqus efficiency. Ntxiv mus, cov txiaj ntsig ntawm microstructure ntawm cov khoom siv kho tshuab ntawm cov npuas dej yog feem ntau vim yog Cf embedded nyob rau hauv lub pore phab ntsa ntawm cov npuas dej. Lub diffusion thiab dissolution ntawm tooj liab-coated ntawm cov carbon fibers nyob rau hauv lub txhuas matrix yuav ua tau ib tug firmer interfacial daim ntawv cog lus ntawm cov fibers thiab cov txhuas matrix, uas pab txhawb rau kev thauj mus los. Lub siab modulus carbon fiber stapled nyob rau hauv lub pore phab ntsa yuav txo tau lub deformation ntawm lub pore phab ntsa nyob rau hauv compression load thiab txhim kho lub load-bearing muaj peev xwm. Tag nrho cov xwm txheej no nyiam Cf / AFS kom ua tiav cov txiaj ntsig siab dua thiab muaj peev xwm nqus lub zog piv rau AFS.

4. Cov lus xaus

Cf/AFS thiab AFS tau npaj los ntawm kev ntim cov hmoov hlau metallurgy hauv txoj haujlwm no. Cov cwj pwm foaming ntawm Cf / AFS thiab AFS tau pom zoo los ntawm cov hluav taws xob synchrotron rau

tshawb xyuas qhov cuam tshuam ntawm Cf ntawm cov npuas nucleation thiab kev loj hlob. Tsis tas li ntawd, Cf ntawm qhov pore morphology, pore faib, thiab compression zog ntawm txhuas foams tau raug tshuaj xyuas kom zoo. Lub ntsiab lus xaus yog raws li nram no:

(1) Synchrotron hluav taws xob nyob rau hauv qhov kev soj ntsuam qhia tau hais tias ob qho tib si Cf / AFS thiab AFS foaming txheej txheem muaj peb theem sib txawv: npuas nucleation, npuas loj hlob thiab merger, thiab solidification.

Hauv kev sib piv rau AFS, cov txheej txheem foaming ntawm Cf / AFS qhia tau tias muaj kev ruaj ntseg dua thiab ua npuas sib xws. AFS yog qhov yooj yim dua rau kev tsim qhov txawv txav loj thiab ntxhib pores thaum lub sijhawm pore evolution txheej txheem. Tsis tas li ntawd, qhov tsis sib xws yog los ntawm cov txiaj ntsig heterogeneous nucleation ntawm Cf, uas tiv thaiv npuas phab ntsa tawg thiab txo cov coalescence thaum nce tus nqi nucleation.

(2) Qhov sib ntxiv ntawm 0.5 wt.% Cf refines qhov sib npaug pore txoj kab uas hla ntawm 2.9 ± 0.2 hli mus rau 1.9 ± 0.1 hli, txo qhov ntxhib pore tsis xws luag. Ib txhij, lub microstructure qhia zoo wettability ntawm Cf, uas yog muab faib raws lub pore phab ntsa thiab gas-khoom interface, yog li pab txhawb kev ua npuas ncauj stability.

(3) Piv nrog AFS, qhov compressive yield zog thiab lub zog nqus peev xwm ntawm Cf / AFS nce li ntawm 40.6% thiab 84.8%, feem. Qhov kev tshawb pom ntawm txoj kev tshawb no tuaj yeem muab cov tswv yim rau kev txhawb nqa ntawm aluminium foam sandwich panels nrog metallurgical bonding interfaces uas muaj peev xwm rau kev siv engineering hauv kev lag luam tsheb thiab aerospace.

Kab lus los ntawm Journal of Materials Research thiab Technology