Materiais de Construção

LUCAS FILIPE MARTINS DA SILVA FERNANDO JORGE LINO ALVES ANTÓNIO TORRES MARQUES

MATERIAIS DE CONSTRUÇÃO

1.2. Ciรชncia e engenharia dos materiais 2 HVWXGR GRV PDWHULDLV SRGH VHU GLYLGLGR HP &LrQFLD GRV 0DWHULDLV H (QJHQKDULD GRV 0DWHULDLV 1D FLrQFLD GRV PDWHULDLV HVWXGD VH D UHODomR HQWUH D HVWUXWXUD H DV SURSULHGD GHV GHVWHV 3RU RXWUR ODGR QD HQJHQKDULD GRV PDWHULDLV SUHWHQGH VH FRP EDVH QD UHODomR HVWUXWXUD SURSULHGDGHV GHVHQYROYHU PDWHULDLV SDUD REWHU XP GHWHUPLQDGR FRQMXQWR GH SURSULHGDGHV 2 FLHQWLVWD GH PDWHULDLV GHVHQYROYH RX VLQWHWL]D QRYRV PDWHULDLV HQTXDQWR R HQJHQKHLUR GH PDWHULDLV GHVHQYROYH XPD GHWHUPLQDGD DSOLFDomR XVDQGR QRYRV PDWHULDLV

1

2V PDWHULDLV HVWmR LQWLPDPHQWH OLJDGRV DR QtYHO GH GHVHQYROYLPHQWR GDV VRFLHGDGHV $V SULPHLUDV FLYLOL]Do}HV HUDP GHVLJQDGDV HP IXQomR GR QtYHO GH GHVHQYROYLPHQWR GRV PDWHULDLV FRPR D ,GDGH GD 3HGUD D ,GDGH GR %URQ]H RX D ,GDGH GR )HUUR 2V SULPHLURV VHUHV KXPDQRV WLQKDP XPD YDULHGDGH PXLWR OLPLWDGD GH PDWHULDLV GLVSRQtYHLV RFRUUHQGR WRGRV HOHV QDWXUDOPHQWH FRPR DV SHGUDV D PDGHLUD D DUJLOD D SHOH H RVVRV GRV DQLPDLV TXH FDoDYDP HWF &RP R SDVVDU GRV DQRV IRUDP VHQGR GHVFREHUWDV WpFQLFDV SDUD PHOKRUDU R FRPSRUWDPHQWR GRV PDWHULDLV FRPR WUDWDPHQWRV WpUPLFRV RX D DGLomR GH HOHPHQWRV 6y PDLV UHFHQWHPHQWH VH FRPSUHHQGHX D UHODomR HQWUH RV HOHPHQWRV TXH FRPS}HP RV PDWHULDLV H DV VXDV SURSULHGDGHV $ SDUWLU GDt FRQVHJXLX VH GHVHQYROYHU PDWHULDLV VLQWpWLFRV FRP SURSULHGDGHV DGDSWDGDV jV QRVVDV QHFHVVLGDGHV 2 DSDUHFLPHQWR GH PXLWDV WHFQRORJLDV Vy IRL SRVVtYHO JUDoDV DR GHVHQYROYLPHQWR GH PDWHULDLV DYDQoDGRV 3RU H[HPSOR RV DYL}HV VXSHUVVyQLFRV Vy R SRGHP VHU UHFRUUHQGR D PDWHULDLV OHYHV H UHVLVWHQWHV FRPR R WLWkQLR RX PDWHULDLV FRPSyVLWRV

CAPร TULO 1

1.1. Histรณria

INTRODUร ร O

1. Introduรงรฃo

CAP├НTULO 1

3

INTRODU├З├ГO

PHVPD FRLVD D UpJXD GHSHQGH GH QRYR GD IRUPD GD UpJXD H GH RXWUD SURSULHGDGH LQWUtQVHFD GR DoR D VXD WHQVmR OLPLWH GH HODVWLFLGDGH RX WHQVmR GH FHGrQFLD ─▒ \ 2V PDWHULDLV FRP XPD HOHYDGD WHQVmR GH FHGrQFLD ─▒ \ WrP XPD HOHYDGD UHVLVWrQFLD j GHIRUPDomR SOiVWLFD FRPR SRU H[HPSOR DoR WUDWDGR RX WLWkQLR VHQGR GLItFHLV GH GHIRUPDU SODVWLFDPHQWH -i R FKXPER WHP XPD EDL[D WHQVmR GH FHGrQFLD ─▒ \ H p PXLWR IiFLO GH GHIRUPDU SODVWL FDPHQWH 4XDQGR RV PHWDLV GHIRUPDP SODVWLFDPHQWH WRUQDP VH PDLV UHVLVWHQWHV GL] VH TXH R PDWHULDO HQFUXD PDV H[LVWH XP OLPLWH FKDPDGR WHQVmR GH URWXUD ─▒U SDUD DOpP GR TXDO R PDWHULDO SDUWH $ GHIRUPDomR SOiVWLFD TXH R PDWHULDO FRQVHJXH DJXHQWDU DQWHV GH URPSHU HVWi UHODFLRQDGD FRP D GXFWLOLGDGH $ )LJXUD F LOXVWUD D FRQVHTXrQFLD GH WHU XP PDWHULDO FRP XPD UHVLVWrQFLD LQDGHTXDGD QXP DYLmR

Figura 1.1. Propriedades mec├вnicas. (a) Situa├з├гo normal, (b) Rigidez insuямБciente (E muito baixo), (c) Resist├кncia mec├вnica insuямБciente (─▒y muito baixo), (d) Tenacidade insuямБciente (Kc muito baixo), (e) Demasiado denso (╚б muito elevado) (adaptado de Ashby et al (2007)).

2XWUD SURSULHGDGH PXLWR LPSRUWDQWH p D WHQDFLGDGH 6H D UpJXD IRVVH IHLWD GH YLGUR RX GH SOiVWLFR WUDQVSDUHQWH QmR HUD SRVVtYHO GHIRUPi OD SODVWLFDPHQWH SDUWLQGR D UpJXD GH UHSHQWH VHP DYLVR 2V PDWHULDLV TXH WrP HVWH WLSR GH FRPSRUWDPHQWR VmR PDWHULDLV

19 CAPÍTULO 2

(OHYDP D WHPSHUDWXUD GR SRQWR $ H EDL[DP D GR SRQWR $ 2V HOHPHQWRV TXH HVWDEL OL]DP D IDVH &)& VmR GHVLJQDGRV JDPDJHQRV %DL[DP D WHPSHUDWXUD $ H HOHYDP D GR SRQWR $ $ )LJXUD PRVWUD HVTXHPDWLFDPHQWH HVVHV GRLV WLSRV GH FRPSRUWDPHQWR $V VROXo}HV VyOLGDV QR IHUUR )HȖ VmR FKDPDGDV DXVWHQLWHV 'HVLJQDP VH SRU Ȗ H VmR &)& $V VROXo}HV VyOLGDV QR IHUUR )HĮ RX )Hį VmR FKDPDGDV IHUULWHV 'HVLJQDP VH SRU Į RX į H VmR &&&

AÇOS

Figura 2.1. Pontos de transformação do ferro; curvas T(t).

Figura 2.2. (a) Elementos alfagenos e (b) gamagenos.

2 FDUERQR p XP HOHPHQWR IRUWHPHQWH JDPDJHQR 3RU HVVD UD]mR H SRUTXH SHUPLWH D IRUPDomR GH FDUERQHWRV R FDUERQR WHP XP SDSHO SDUWLFXODU QDV OLJDV IHUURVDV 'H IDFWR HVWi VHPSUH SUHVHQWH GHYLGR DR PRGR GH HODERUDomR (PERUD DV OLJDV LQGXVWULDLV DoRV H IHUURV IXQGLGRV PHVPR QmR OLJDGDV FRQWHQKDP VHPSUH RXWURV HOHPHQWRV p QHFHVViULR HVWXGDU R VLVWHPD ELQiULR IHUUR FDUERQR TXH VHUYH GH UHIHUrQFLD DR HVWXGR GH WRGDV DV OLJDV IHUURVDV 2 FRQMXQWR GDV OLJDV ELQiULDV IHUUR FDUERQR DSUHVHQWD DV IDVHV VHJXLQWHV

CAPร TULO 2

31

Aร OS

(P UHVXPR R DXPHQWR GD YHORFLGDGH GH DUUHIHFLPHQWR FRQGX] D HVWUXWXUDV FDGD YH] PDLV ยฟQDV WDQWR GRV JUmRV IHUUtWLFRV SROLJRQDLV HTXLD[LDLV SROLJRQDLV LUUHJXODUHV DFLFXODUHV FRPR GD SHUOLWH 2 FRQWUROR GD YHORFLGDGH GH DUUHIHFLPHQWR p SRUWDQWR XP PHLR GH FRQWURODU D PLFURHVWUXWXUD GR DoR 2 GLDJUDPD GD )LJXUD FRUUHVSRQGH D XPD YHORFLGDGH GH DUUHIHFLPHQWR GHWHUPLQDGD

Figura 2.14. Evoluรงรตes microestruturais de um aรงo com 0,4%C durante o arrefecimento.

MATERIAIS DE CONSTRUÇÃO

48

PARTE A: METAIS

7UDQVIRUPDomR SHUOtWLFD (VWD WUDQVIRUPDomR LQWHUYpP SDUD WHPSHUDWXUDV HOHYDGDV GR GRPtQLR GDV WUDQVIRUPD o}HV LVRWpUPLFDV GD DXVWHQLWH 2 DJUHJDGR ) & IRUPDGR p GR WLSR SHUOtWLFR ODPHODU $ IDVH QXFOHDQWH p R FDUERQHWR 2 FUHVFLPHQWR FRRSHUDWLYR GDV ODPHODV ID] VH VHP UHODomR FULVWDORJUi¿FD FRP D IDVH PmH DXVWHQtWLFD 2 HVSDoDPHQWR LQWHUODPHODU GLPLQXL FRP D WHPSHUDWXUD FRQGX]LQGR D PLFURHVWUXWXUDV PXLWR ¿QDV SDUD YDORUHV GH 7L VLWXDGRV QD ]RQD LQIHULRU GR GRPtQLR SHUOtWLFR 3RU FRQVHJXLQWH R FRQVWLWXLQWH IRUPDGR WHP XPD GXUH]D WDQWR PDLV HOHYDGD TXDQWR PDLV EDL[D IRU D WHPSHUDWXUD GH IRUPDomR 7L $ WUDQVIRUPDomR SHUOtWLFD ID] LQWHUYLU LPSRUWDQWHV IHQyPHQRV GH GLIXVmR GR FDUERQR H GRV HOHPHQWRV GH OLJD HP VXEVWLWXLomR QD DXVWHQLWH 2V FDUERQHWRV IRUPDGRV VmR TXHU FHPHQWLWHV OLJDGDV TXHU FDUERQHWRV OLJDGRV SDUD RV HOHPHQWRV PDLV FDUERUtJHQRV 7UDQVIRUPDo}HV EDLQtWLFDV ¬ PHGLGD TXH 7L EDL[D D GLIXVmR GRV HOHPHQWRV HP VXEVWLWXLomR WRUQD VH PDLV GLItFLO H D WUDQVIRUPDomR SHUOtWLFD p SURJUHVVLYDPHQWH VXEVWLWXtGD SRU XPD QRYD WUDQVIRUPD omR GLWD EDLQtWLFD 1D WUDQVIRUPDomR EDLQtWLFD D IDVH QXFOHDQWH p D IHUULWH )RUPD VH SRU FRUWH GD UHGH GH DXVWHQLWH SRU JHUPLQDomR VHJXQGR SODQRV RFWDpGULFRV GD DXV WHQLWH H H[LVWHP UHODo}HV FULVWDORJUi¿FDV GR WLSR .XUGMXPRY H 6DFKV >^ `$ ^ `) !$ !)@ 2V FDUERQHWRV IRUPDGRV VmR HVVHQFLDOPHQWH FDUERQHWRV GH IHUUR R FDUERQR VHQGR R ~QLFR HOHPHQWR TXH WHP XP FRH¿FLHQWH GH GLIXVmR VX¿FLHQWHPHQWH HOHYDGR 'LVWLQJXHP VH GRLV WLSRV SULQFLSDLV GH EDLQLWH 1D ]RQD VXSHULRU GR GRPtQLR EDLQtWLFR EDLQLWH VXSHULRU D IHUULWH IRUPD VH HP µULSDV¶ H DV SODTXHWDV GH FDUERQH WRV GH IHUUR SUHFLSLWDP HQWUH HVVDV ULSDV DSUR[LPDGDPHQWH SDUDOHODV D HODV )LJXUD D $ SUHVHQoD HQWUH ULSDV GD IDVH FDUERQHWR IUiJLO FRQIHUH j EDLQLWH VXSHULRU PiV FDUDFWHUtVWLFDV GH UHVLOLrQFLD

Figura 2.30. Estruturas bainíticas observadas em microscopia eletrónica. (a) Bainite superior e (b) Bainite inferior.

CAPร TULO 2

69

Aร OS

GD SHoD GD H[LVWrQFLD GH IHQyPHQRV H[R RX HQGRWpUPLFRV DTXDQGR GDV WUDQVIRUPDo}HV GH IDVHV PDV WDPEpP GR SRGHU GH DUUHIHFLPHQWR GR ร XLGR GH WrPSHUD $ LPSRUWkQFLD SUiWLFD GR FRQKHFLPHQWR GDV OHLV GH DUUHIHFLPHQWR H[SOLFD R HVIRUoR WDQWR WHyULFR FRPR H[SHULPHQWDO SDUD IRUQHFHU DR XWLOL]DGRU GDGRV WmR SUHFLVRV TXDQWR SRVVtYHO VREUH HVWH SUREOHPD 2V UHVXOWDGRV DSUHVHQWDP VH VRE GLYHUVDV IRUPDV YiOLGDV SDUD WRGDV DV FODVVHV QmR OLJDGDV RX IUDFDPHQWH OLJDGDV SDUD DV TXDLV RV YDORUHV GDV FRQGXWLYLGDGHV WpUPLFDV VmR SRXFR GLIHUHQWHV &XUYDV GH DUUHIHFLPHQWR SDUD IRUPDV VLPSOHV H GLYHUVRV PHLRV VmR UHSUHVHQWDGDV QDV PHVPDV FRRUGHQDGDV TXH DV FXUYDV 75& $ )LJXUD Gi R H[HPSOR GH OHLV GH DUUHIHFLPHQWR DR yOHR SDUD YHLRV 7DPEpP H[LVWHP FXUYDV VHPHOKDQWHV SDUD D iJXD H SDUD R DU

Figura 2.51. Curvas de arrefecimento em รณleo de veios de diversos diรขmetros, segundo o atlas IRSID.

$ VXSHUSRVLomR GH WUDQVSDUHQWHV DRV GLDJUDPDV 75& SHUPLWH GHWHUPLQDU DV GXUH]DV DSyV WrPSHUD H D FRQVWLWXLomR GR DoR $ )LJXUD PRVWUD WDO DSOLFDomR SDUD R DoR &U 3RU H[HPSOR SRGH VH REVHUYDU TXH R DoR WHPSHUD SDUD YHLRV GH H PP 8P YHLR FRP XP GLkPHWUR GH PP ยฟFD UHFR]LGR 'HVSUH]D VH $UHV QHVVDV HVWLPDWLYDV 3URFHGHQGR GHVWH PRGR SRGH VH HP SULQFtSLR GHWHUPLQDU R WUDWDPHQWR WpUPLFR QHFHVViULR HVFROKD GR PHLR GH WrPSHUD SDUD FDUDFWHUtVWLFDV DSyV WrPSHUD ยฟ[DGDV SDUD XPD SHoD GH GLPHQV}HV H GH FODVVH FRQKHFLGDV 1R HQWDQWR HVWH PpWRGR p EDVWDQWH OLPLWDGR H HPERUD FRQVWLWXD

2.4.7.4. Diâmetro crítico

MATERIAIS DE CONSTRUÇÃO

80

PARTE A: METAIS

2 GLkPHWUR FUtWLFR SDUD XP GDGR PHLR GH DUUHIHFLPHQWR p DTXHOH D SDUWLU GR TXDO GHL[D GH DSDUHFHU QR Q~FOHR GD SHoD XPD ]RQD FRP GXUH]D LQIHULRU D GH PDUWHQVLWH )LJXUD

FRQVLGHUDQGR TXH GH PDUWHQVLWH UHSUHVHQWD XPD HVWUXWXUD QmR WHPSHUDGD

$ GHWHUPLQDomR GR GLkPHWUR FUtWLFR HVWi DVVRFLDGD jV FXUYDV GH SHQHWUDomR GH WrPSHUD XPD YH] TXH D GXUH]D GHYH VHU PHGLGD DR ORQJR GD VHFomR GH FDGD GLkPHWUR WDO FRPR QD GHWHUPLQDomR GDV FXUYDV HP 8 FRPR PRVWUDGR QD )LJXUD $ WHPSHUDELOLGDGH DXPHQWD FRP R GLkPHWUR FUtWLFR (VWH PpWRGR p PXLWR PRURVR GHYLGR jV YiULDV PHGLo}HV GH PLFURGXUH]D H R GLkPHWUR FUtWLFR GHSHQGH GR PHLR GH DUUHIHFLPHQWR

Figura 2.63. Determinação do diâmetro crítico (adaptado de Soares (2002)).

2.4.7.5. Utilização do ensaio Jominy 2 HQVDLR -RPLQ\ WHP SRU REMHWLYR D REWHQomR QXPD Vy RSHUDomR H QXP SURYHWH QRUPDOL ]DGR GH LQGLFDo}HV JOREDLV VREUH D WHPSHUDELOLGDGH GH XP DoR (VWH HQVDLR HVWi GHVFULWR QD QRUPD SRUWXJXHVD 13 e UHDOL]DGR HP WUrV HWDSDV ¾ DXVWHQLWL]DomR GH XP SURYHWH PDTXLQDGR QR DoR D WHVWDU H GH GLPHQV}HV QRUPD OL]DGDV )LJXUD $ WHPSHUDWXUD GH DXVWHQLWL]DomR GHSHQGH GR WLSR GH DoR H R WHPSR GH DXVWHQLWL]DomR p GH PLQ ¾ DUUHIHFLPHQWR QD SRQWD SRU XP MDWR GH iJXD HP FRQGLo}HV LPSRVWDV

4.2.1. Latões (ligas Cu-Zn, 5 a 45% de Zn) 2V ODW}HV FRQWrP HQWUH D GH ]LQFR H HYHQWXDOPHQWH RXWURV HOHPHQWRV HP PDLV EDL[DV SURSRUo}HV SDUD PHOKRUDUHP SURSULHGDGHV HVSHFt¿FDV 3RVVXHP XPD FRU TXH YDL GR URVDGR DR DPDUHOR FRP XP WHRU HP ]LQFR FUHVFHQWH R TXH OLJDGR D XPD ERD UHVLVWrQFLD j FRUURVmR H XPD ERD DSWLGmR DRV WUDWDPHQWRV GH VXSHUItFLH SHUPLWH UHDOL]DU SHoDV GH DJUDGiYHO DVSHWR 3RGHP VHU IXQGLGRV WUDEDOKDGRV D IULR RX D TXHQWH VHJXQGR D VXD FRPSRVLomR 6mR IDFLOPHQWH HVWDPSDGRV HPEXWLGRV RX PDTXLQDGRV $ 7DEHOD DSUHVHQWD D FRPSRVLomR SURSULHGDGHV H DSOLFDo}HV GH DOJXPDV OLJDV GH FREUH

MATERIAIS DE CONSTRUÇÃO

136

/DWmR GH FDUWXFKRV

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/DWmR GH 0XQW]

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%URQ]H IRVIRURVR

6Q 3

&XSUR DOXPtQLR &XSUR QtTXHO

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5HVLVWrQFLD j GHIRUPDomR SOiVWLFD 03D

'XFWLOLGDGH H[WHQVmR DSyV URWXUD

5HFR]LGR

(QGXUHFLGR SRU ± SUHFLSLWDomR HVWUXWXUDO 5HFR]LGR

(QFUXDGR D IULR + GXUR

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(QFUXDGR D IULR

%URQ]H DR 6Q =Q FKXPER %URQ]H DR )H $O DOXPtQLR

5HFR]LGR

(QFUXDGR D IULR + GXUR

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(QFUXDGR D IULR 5HFR]LGR

(QFUXDGR D IULR + GXUR

/LJDV YD]DGDV /DWmR DR =Q 3E %UXWR GH FKXPER 6Q YD]DPHQWR %UXWR GH YD]DPHQWR %UXWR GH YD]DPHQWR

± ±

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5HVLVWrQFLD j WUDomR 03D

&RPSRVLomR PiVVLFD GRV HOHPHQWRV GH OLJD

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(VWDGR HVWUXWXUDO

PARTE A: METAIS

1RPH GD OLJD

Tabela 4.7. Composição, propriedades e aplicações de algumas ligas de cobre (adaptado de Callister (2000)).

)LR HOpWULFR UHELWHV MXQWDV SDQHODV SUHJRV WHOKDGRV 0RODV SLQRV GH GLVSDUR EXFKDV YiOYXODV GLDIUDJPDV 1~FOHRV GH UDGLDGRU GH DXWRPyYHLV FRPSRQHQWHV GH PXQLo}HV GLVSRVLWLYRV HOpWULFRV GH OkPSDGDV URGDSpV 3DUDIXVRV H SRUFDV YDUDV GH EUDVDJHP SOD FDV GH FRQGHQVDGRU WXERV GH SHUPXWDGRUHV GH FDORU SHoDV IRUMDGDV D TXHQWH )ROHV GLVFRV GH HPEUDLDJHP GLDIUDJPDV IXVtYHLV FOLSV PRODV +pOLFHV PDULQKDV SiV GH WXUELQDV &RPSRQHQWHV GH FRQGHQVDGRUHV H SHUPXWDGRUHV GH FDORU WXEXODo}HV GH iJXD VDOJDGD )HUUDJHQV GH PyYHLV FRPSRQHQWHV GH UDGLDGRUHV FRPSRQHQWHV GH yWLFDV EUDoDGHLUDV GH EDWHULD 5RODPHQWRV EXFKDV DQpLV GH SLVWmR FRP SRQHQWHV GH PiTXLQDV D YDSRU HQJUHQDJHQV 5RODPHQWRV HQJUHQDJHQV EXFKDV YiOYXODV

4.2.1.1. Latões simples (binários Cu-Zn) 6mR GHVFULWRV SHOR GLDJUDPD GH HTXLOtEULR GD )LJXUD 'LVWLQJXHP VH DV WUrV VROXo}HV VyOLGDV Į ȕ H Ȗ 1RWH TXH D IDVH ȕ SRGH WUDQVIRUPDU VH QXPD IDVH ȕ¶ RUGHQDGD TXH p GXUD H IUiJLO 2V ODW}HV LQGXVWULDLV GLYLGHP VH HP GXDV FDWHJRULDV

Figura 10.3. Mรณdulo de Young vs. densidade de vรกrios materiais (adaptado de Ashby et al. (2007)).

$ EDL[D ULJLGH] QR HVWDGR LVRWUySLFR )LJXUD HVWi HVVHQFLDOPHQWH OLJDGD j GHQVLGDGH GD HQHUJLD GDV OLJDo}HV UHVSRQViYHLV SHOD FRHVmR GDV FDGHLDV 1RV PHWDLV H RXWURV PDWH ULDLV LQRUJkQLFRV D FRHVmR p DVVHJXUDGD SRU XPD UHGH WULGLPHQVLRQDO GH OLJDo}HV IRUWHV PHWiOLFDV LyQLFDV RX FRYDOHQWHV 1RV SROtPHURV VHQGR DV OLJDo}HV IRUWHV DR ORQJR GD FDGHLD H IUDFDV SHUSHQGLFXODUPHQWH jV FDGHLDV HVWDV SRGHP IDFLOPHQWH GHVORFDU VH XPDV HP UHODomR jV RXWUDV 1R HQWDQWR VH WRGDV DV FDGHLDV IRUHP SDUDOHODV ยฟEUDV RULHQWDGDV GH .(9/$5ย SRODPLGD DURPiWLFD GH SROLHWLOHQR HWF D ULJLGH] H D UHVLVWrQFLD QD GLUHomR GDV FDGHLDV p GD PHVPD RUGHP GH JUDQGH]D RX DWp VXSHULRU j GRV PHWDLV $ GHVLJQDomR GH SROtPHURV RX D FRQVLGHUDomR GD HVWUXWXUD TXtPLFD GH XP SROtPHUR D SDUWLU GR FRQKHFLPHQWR GR VHX QRPH p XPD iUHD TXH IUHTXHQWHPHQWH FDXVD JUDQGHV GLยฟFXOGDGHV D TXHP VH LQLFLD QR HVWXGR GHVWHV PDWHULDLV (VWH SUREOHPD WRUQD VH PDLV FRPSOH[R SHOD YDULHGDGH GH GHVLJQDo}HV FRPHUFLDLV TXH VmR XVDGDV SDUD GHVFUHYHU FHUWRV SROtPHURV H J SROLDPLGD 3$ RX 1</21ย 1R FDVR GH SROtPHURV GH DGLomR RX QRV

CAPร TULO 10

235

ESTRUTURA

$ EDL[D GHQVLGDGH GH XP PDWHULDO HVWi DFLPD GH WXGR OLJDGD j PDVVD DWyPLFD GRV HOH PHQWRV TXH R FRPS}HP &RPR RV SROtPHURV VmR HVVHQFLDOPHQWH IRUPDGRV SRU iWRPRV OHYHV FRPR R FDUERQR RX R KLGURJpQLR VmR GRV PDWHULDLV PHQRV GHQVRV TXH H[LVWHP )LJXUD H )LJXUD

2 SHVR PROHFXODU PpGLR p GH┬┐QLGR FRPR D VRPD GH SURGXWRV GR SHVR PROHFXODU GH FDGD IUDomR 0L PXOWLSOLFDGD SHOR SHVR GHVVD IUDomR :L

MATERIAIS DE CONSTRU├З├ГO

248

PARTE C: POL├НMEROS

(10.3)

Figura 10.22. InямВu├кncia do peso molecular nas propriedades de ямВuxo, mec├вnicas e f├нsicas dos pol├нmeros (adaptado de Ehrenstein (2001).

10.3.2. Pol├нmeros tridimensionais 8PD UHGH LGHDO p XPD UHGH QD TXDO WRGDV DV FDGHLDV VmR HODVWLFDPHQWH DWLYDV L H DVVH JXUDP D OLJDomR HQWUH GRLV QyV VHP TXH GRLV RXWURV QyV HVWHMDP OLJDGRV SRU PDLV GR TXH XPD FDGHLD

12.1.1. Extrusão

MATERIAIS DE CONSTRUÇÃO

316

PARTE C: POLÍMEROS

$ H[WUXVmR p XPD WpFQLFD GH WUDQVIRUPDomR GRV WHUPRSOiVWLFRV TXH SHUPLWH REWHU HP FRQWtQXR REMHWRV DFDEDGRV RX VHPL SURGXWRV FRP XPD VHFomR FRQVWDQWH $ H[WUXVmR p XP SURFHVVR FRQWtQXR QR TXDO XP SDUDIXVR IRUQHFH XP ÀX[R FRQWtQXR GH SROtPHUR µIXQGLGR¶ SDUD XPD ¿HLUD TXH FRQIHUH DR SURGXWR XPD IRUPD SUp GHWHUPLQDGD DV GLPHQV}HV GR SURGXWR VROLGL¿FDGR H DUUHIHFLGR GHSHQGHP ± SDUD DOpP GD IRUPD H GLPHQV}HV GD ¿HLUD ± GDV FRQGLo}HV GH SURFHVVDPHQWR LQFOXLQGR R DUUHIHFLPHQWR *UkQXORV GH SROtPHUR VmR LQWURGX]LGRV QXP SDUDIXVR VHP ¿P TXH URGD GHQWUR GH XP FLOLQGUR DTXHFLGR FRPR VH PRVWUD QD )LJXUD

Figura 12.1. Esquema de uma extrusora.

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13.6.3.1. Crazing

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0XLWRV SROtPHURV FRPR R SROLHWLOHQR R SROLSURSLOHQR H D SROLDPLGD WrP XP FRPSRU WDPHQWR VHPHOKDQWH DR YLVWR QD VHFomR DQWHULRU j WHPSHUDWXUD DPELHQWH 2XWURV FRP XPD PDLRU 7J FRPR R SROLHVWLUHQR Vy WrP HVVH FRPSRUWDPHQWR D WHPSHUDWXUDV PDLV DOWDV ¬ WHPSHUDWXUD DPELHQWH HVVHV SROtPHURV URPSHP SHOD IRUPDomR GH XPD JUDQGH TXDQWLGDGH GH SHTXHQDV IHQGDV FUD]LQJ FRPR PRVWUDGR QD )LJXUD $V SHTXHQDV IHQGDV WRUQDP R SROtPHUR EUDQFR DFRQWHFHQGR SRU H[HPSOR TXDQGR VH GREUDP SHoDV GH SOiVWLFR GH WRGRV RV GLDV FRPR WDPSDV GH HVIHURJUi¿FD $V SHTXHQDV IHQGDV PDUFDP R LQtFLR GD IUDWXUD SRUTXH SRXFR GHSRLV GD VXD IRUPDomR XPD IHQGD GH JUDQGHV GLPHQV}HV GHVHQYROYH VH OLJDQGR DV IHQGDV SHTXHQDV H SURSDJDQGR DWp j URWXUD

Figura 13.12. Rotura por crazing num polímero.

13.6.3.2. Bandas de corte (shear bands) 2V SROtPHURV TXH WrP XPD OLPLWDGD GXFWLOLGDGH HP WUDomR GHYLGR DR IHQyPHQR GH FUD]LQJ SRGHP QR HQWDQWR DSUHVHQWDU XPD HOHYDGD FDSDFLGDGH GH GHIRUPDomR j FRPSUHVVmR IRUPDQGR EDQGDV GH FRUWH VKHDU EDQGV FRPR PRVWUDGR QD )LJXUD &DGD EDQGD FRUUHVSRQGH D XPD GHIRUPDomR GH FRUWH ¬ PHGLGD TXH DXPHQWD R Q~PHUR GH EDQGDV D GHIRUPDomR WRWDO YDL WDPEpP DXPHQWDQGR

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Figura 13.18. Fluência à tração, a 20 oC, dum polipropileno (PP) homopolímero ICI (adaptado de "PROPATHENE" Polypropylene Data for Design, Technical Service Note PP110 3rd Edition ICI 1979).

CAPĂ?TULO 13

361

MATERIAIS DE CONSTRUร ร O

376

PARTE D: COMPร SITOS

3RGHP WHU XP FRPSRUWDPHQWR DOWDPHQWH DQLVRWUySLFR HP SDUWLFXODU RV GH UHIRUoRV XQL GLUHFLRQDLV Mi TXH D VXD PDWUL] p PXLWR PHQRV UHVLVWHQWH H UtJLGD GR TXH DV ยฟEUDV 7HP KDYLGR UHFHQWHPHQWH DOJXP LQWHUHVVH QRV FRPSyVLWRV GH PDWUL] PHWiOLFD FRPR DOXPtQLR UHIRUoDGR FRP SDUWtFXODV GH FHUkPLFR RX WLWkQLR FRP ยฟEUDV 1R FDVR GRV FRPSyVLWRV GH PDWUL] PHWiOLFD RV DXPHQWRV GH UHVLVWrQFLD H GH ULJLGH] QmR VmR VXEVWDQFLDLV VHQGR R FRPSRUWDPHQWR D DOWD WHPSHUDWXUD RX DV SURSULHGDGHV WULEROyJLFDV DV SULQFLSDLV PRWL YDo}HV 2V FRPSyVLWRV GH PDWUL] PHWiOLFD DLQGD WrP SRXFD H[SUHVVmR D QtYHO LQGXVWULDO FRQWUDULDPHQWH DRV FRPSyVLWRV GH PDWUL] SROLPpULFD 1R FDVR GRV FRPSyVLWRV GH PDWUL] FHUkPLFD D SURSULHGDGH TXH VH WHQWD PHOKRUDU p D WHQDFLGDGH PDV WDO ยฑ FRPR QR FDVR GRV FRPSyVLWRV FRP PDWUL] PHWiOLFD ยฑ R VHX GHVHQYROYLPHQWR DLQGD VH HQFRQWUD QXPD IDVH LQLFLDO

Figura 14.1. Classi๏ฌ caรงรฃo dos vรกrios tipos de compรณsitos.

Figura 14.2. (a) Microestrutura esquemรกtica de compรณsitos de matriz polimรฉrica (laminado de epรณxido reforรงado com ๏ฌ bras de carbono), (b) metรกlica (partรญculas de carboneto de silรญcio num alumรญnio) e (c) cerรขmica (mono๏ฌ lamentos de carboneto de silรญcio num vidro).

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MATERIAIS DE CONSTRUÇÃO

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PARTE D: COMPÓSITOS

Figura 15.1. Método de moldação manual.

Figura 15.2. Enrolamento filamentar.

15.1.1.3. Pultrusão &RPR QR HQURODPHQWR ¿ODPHQWDU QD SXOWUXVmR DV ¿EUDV VmR HP SULPHLUR OXJDU LPSUHJ QDGDV SRU XP EDQKR GH UHVLQD SDVVDQGR D VHJXLU SRU XPD ¿HLUD FRP XPD GHWHUPLQDGD JHRPHWULD HP TXH D UHVLQD p FXUDGD )LJXUD 2 FRPSyVLWR p SX[DGR SRU URORV ORFDOL]DGRV D VHJXLU j ¿HLUD 8P VLVWHPD GH FRUWH QR ¿QDO GR SURFHVVR SHUPLWH REWHU XP

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Figura 15.4. Moldaรงรฃo por RTM.

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CAPร TULO 15

15.1.1.4. Moldaรงรฃo por transferรชncia/injeรงรฃo de resina

FABRICAร ร O DE COMPร SITOS

Figura 15.3. Pultrusรฃo.

(16.2)

2 PyGXOR GR PHVPR PDWHULDO VROLFLWDGR SHUSHQGLFXODUPHQWH jV ¿EUDV (F )LJXUD E

p PXLWR PHQRU VHQGR GDGR SRU (16.3)

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MATERIAIS DE CONSTRUÇÃO

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PARTE D: COMPÓSITOS

(16.4)

Figura 16.1. (a) Fibras unidirecionais a 0° (paralelas à direção de solicitação). (b) Fibras unidirecionais a 90° (perpendiculares à direção de solicitação). (c) Fibras em tecido ou laminado 0-90°. (d) Laminado 0-45-90-135 quase isotrópico.

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MATERIAIS DE CONSTRUร ร O

420

PARTE D: COMPร SITOS

(P SDtVHV FRP FOLPD IULR R DXPHQWR GH WHPSHUDWXUD GR FLPHQWR p XVDGR SDUD HYLWDU R FRQJHODPHQWR GD iJXD 1R HQWDQWR SDUD JUDQGHV HVWUXWXUDV FRPR EDUUDJHQV R DTXHFL PHQWR p SUREOHPiWLFR H GHYHP VHU XVDGRV WXERV GH DUUHIHFLPHQWR HPEHELGRV QR EHWmR SDUD HYDFXDU R FDORU TXH VmR GHL[DGRV QR OXJDU DWXDQGR FRPR XPD HVSpFLH GH UHIRUoR

Figura 16.10. Presa e endurecimento do cimento. (a) Mistura do cimento com รกgua. (b) Presa do cimento apรณs 15 minutos. (c) Endurecimento apรณs dias.

MATERIAIS DE CONSTRUÇÃO

430

PARTE D: COMPÓSITOS

$V FpOXODV SULQFLSDLV FKDPDGDV µ¿EUDV¶ RX µWUDTXHtGRV¶ GD PDGHLUD HVWmR DOLQKDGDV D[LDOPHQWH VHQGR DR ORQJR GHVWD GLUHomR TXH D PDGHLUD p PDLV UHVLVWHQWH $ PDGHLUD FRQWpP DQpLV QD GLUHomR UDGLDO GH GLIHUHQWHV GHQVLGDGHV HP IXQomR GDV HVWDo}HV 1R LQYHUQR H QR RXWRQR R FUHVFLPHQWR p OHQWR R TXH Gi GHQVLGDGHV HOHYDGDV $ PDLRU SDUWH GR FUHVFLPHQWR RFRUUH QR FDPELXP TXH ¿FD PHVPR SRU EDL[R GD FDVFD $ SDUWH UHVWDQWH GD PDGHLUD HVWi SUDWLFDPHQWH PRUWD WHQGR XPD IXQomR HVWUXWXUDO SDUD VHJXUDU D iUYRUH

Figura 17.5. Estrutura macroscópica da madeira com o eixo de coordenadas axial, radial e tangencial.

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