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

MATERIAIS DE CONSTRUÇÃO


1.2. Ciรชncia e engenharia dos materiais 2HVWXGRGRVPDWHULDLVSRGHVHUGLYLGLGRHP&LrQFLDGRV0DWHULDLVH(QJHQKDULDGRV 0DWHULDLV1DFLrQFLDGRVPDWHULDLVHVWXGDVHDUHODomRHQWUHDHVWUXWXUDHDVSURSULHGD GHVGHVWHV3RURXWURODGRQDHQJHQKDULDGRVPDWHULDLVSUHWHQGHVHFRPEDVHQDUHODomR HVWUXWXUDSURSULHGDGHVGHVHQYROYHUPDWHULDLVSDUDREWHUXPGHWHUPLQDGRFRQMXQWRGH SURSULHGDGHV2FLHQWLVWDGHPDWHULDLVGHVHQYROYHRXVLQWHWL]DQRYRVPDWHULDLVHQTXDQWR RHQJHQKHLURGHPDWHULDLVGHVHQYROYHXPDGHWHUPLQDGDDSOLFDomRXVDQGRQRYRVPDWHULDLV

1

2VPDWHULDLVHVWmRLQWLPDPHQWHOLJDGRVDRQtYHOGHGHVHQYROYLPHQWRGDVVRFLHGDGHV $VSULPHLUDVFLYLOL]Do}HVHUDPGHVLJQDGDVHPIXQomRGRQtYHOGHGHVHQYROYLPHQWRGRV PDWHULDLVFRPRD,GDGHGD3HGUDD,GDGHGR%URQ]HRXD,GDGHGR)HUUR2VSULPHLURV VHUHVKXPDQRVWLQKDPXPDYDULHGDGHPXLWROLPLWDGDGHPDWHULDLVGLVSRQtYHLVRFRUUHQGR WRGRVHOHVQDWXUDOPHQWHFRPRDVSHGUDVDPDGHLUDDDUJLODDSHOHHRVVRVGRVDQLPDLV TXHFDoDYDPHWF&RPRSDVVDUGRVDQRVIRUDPVHQGRGHVFREHUWDVWpFQLFDVSDUDPHOKRUDU RFRPSRUWDPHQWRGRVPDWHULDLVFRPRWUDWDPHQWRVWpUPLFRVRXDDGLomRGHHOHPHQWRV6y PDLVUHFHQWHPHQWHVHFRPSUHHQGHXDUHODomRHQWUHRVHOHPHQWRVTXHFRPS}HPRVPDWHULDLV HDVVXDVSURSULHGDGHV$SDUWLUGDtFRQVHJXLXVHGHVHQYROYHUPDWHULDLVVLQWpWLFRVFRP SURSULHGDGHVDGDSWDGDVjVQRVVDVQHFHVVLGDGHV2DSDUHFLPHQWRGHPXLWDVWHFQRORJLDVVy IRLSRVVtYHOJUDoDVDRGHVHQYROYLPHQWRGHPDWHULDLVDYDQoDGRV3RUH[HPSORRVDYL}HV VXSHUVVyQLFRVVyRSRGHPVHUUHFRUUHQGRDPDWHULDLVOHYHVHUHVLVWHQWHVFRPRRWLWkQLR RXPDWHULDLVFRPSyVLWRV

CAPรTULO 1

1.1. Histรณria

INTRODUร‡รƒO

1. Introduรงรฃo


CAP├НTULO 1

3

INTRODU├З├ГO

PHVPDFRLVD DUpJXDGHSHQGHGHQRYRGDIRUPDGDUpJXDHGHRXWUDSURSULHGDGHLQWUtQVHFD GRDoRDVXDWHQVmROLPLWHGHHODVWLFLGDGHRXWHQVmRGHFHGrQFLD─▒ \2VPDWHULDLVFRP XPDHOHYDGDWHQVmRGHFHGrQFLD─▒ \WrPXPDHOHYDGDUHVLVWrQFLDjGHIRUPDomRSOiVWLFD FRPRSRUH[HPSORDoRWUDWDGRRXWLWkQLR VHQGRGLItFHLVGHGHIRUPDUSODVWLFDPHQWH -iRFKXPERWHPXPDEDL[DWHQVmRGHFHGrQFLD─▒ \HpPXLWRIiFLOGHGHIRUPDUSODVWL FDPHQWH4XDQGRRVPHWDLVGHIRUPDPSODVWLFDPHQWHWRUQDPVHPDLVUHVLVWHQWHV GL]VH TXHRPDWHULDOHQFUXD PDVH[LVWHXPOLPLWHFKDPDGRWHQVmRGHURWXUD─▒USDUDDOpPGR TXDORPDWHULDOSDUWH$GHIRUPDomRSOiVWLFDTXHRPDWHULDOFRQVHJXHDJXHQWDUDQWHVGH URPSHUHVWiUHODFLRQDGDFRPDGXFWLOLGDGH$)LJXUDFLOXVWUDDFRQVHTXrQFLDGHWHU XPPDWHULDOFRPXPDUHVLVWrQFLDLQDGHTXDGDQXPDYLmR

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)).

2XWUDSURSULHGDGHPXLWRLPSRUWDQWHpDWHQDFLGDGH6HDUpJXDIRVVHIHLWDGHYLGURRX GH SOiVWLFR WUDQVSDUHQWH QmR HUD SRVVtYHO GHIRUPiOD SODVWLFDPHQWH SDUWLQGR D UpJXD GHUHSHQWHVHPDYLVR2VPDWHULDLVTXHWrPHVWHWLSRGHFRPSRUWDPHQWRVmRPDWHULDLV


19 CAPÍTULO 2

(OHYDPDWHPSHUDWXUDGRSRQWR$HEDL[DPDGRSRQWR$2VHOHPHQWRVTXHHVWDEL OL]DPDIDVH&)&VmRGHVLJQDGRVJDPDJHQRV%DL[DPDWHPSHUDWXUD$ HHOHYDPDGR SRQWR$$)LJXUDPRVWUDHVTXHPDWLFDPHQWHHVVHVGRLVWLSRVGHFRPSRUWDPHQWR $VVROXo}HVVyOLGDVQRIHUUR)HȖVmRFKDPDGDVDXVWHQLWHV'HVLJQDPVHSRUȖHVmR &)&$VVROXo}HVVyOLGDVQRIHUUR)HĮRX)HįVmRFKDPDGDVIHUULWHV'HVLJQDPVHSRU ĮRXįHVmR&&&

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 IRUPDomRGHFDUERQHWRVRFDUERQRWHPXPSDSHOSDUWLFXODUQDVOLJDVIHUURVDV'HIDFWR HVWiVHPSUHSUHVHQWHGHYLGRDRPRGRGHHODERUDomR(PERUDDVOLJDVLQGXVWULDLVDoRV HIHUURVIXQGLGRVPHVPRQmROLJDGDVFRQWHQKDPVHPSUHRXWURVHOHPHQWRVpQHFHVViULR HVWXGDURVLVWHPDELQiULRIHUURFDUERQRTXHVHUYHGHUHIHUrQFLDDRHVWXGRGHWRGDVDV OLJDVIHUURVDV2FRQMXQWRGDVOLJDVELQiULDVIHUURFDUERQRDSUHVHQWDDVIDVHVVHJXLQWHV


CAPรTULO 2

31

Aร‡OS

(PUHVXPRRDXPHQWRGDYHORFLGDGHGHDUUHIHFLPHQWRFRQGX]DHVWUXWXUDVFDGDYH] PDLVยฟQDVWDQWRGRVJUmRVIHUUtWLFRV SROLJRQDLVHTXLD[LDLV SROLJRQDLVLUUHJXODUHV  DFLFXODUHV FRPRGDSHUOLWH2FRQWURORGDYHORFLGDGHGHDUUHIHFLPHQWRpSRUWDQWRXP PHLRGHFRQWURODUDPLFURHVWUXWXUDGRDoR2GLDJUDPDGD)LJXUDFRUUHVSRQGHD XPDYHORFLGDGHGHDUUHIHFLPHQWRGHWHUPLQDGD

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


MATERIAIS DE CONSTRUÇÃO

48

PARTE A: METAIS

7UDQVIRUPDomRSHUOtWLFD (VWDWUDQVIRUPDomRLQWHUYpPSDUDWHPSHUDWXUDVHOHYDGDVGRGRPtQLRGDVWUDQVIRUPD o}HVLVRWpUPLFDVGDDXVWHQLWH2DJUHJDGR )& IRUPDGRpGRWLSRSHUOtWLFRODPHODU$ IDVHQXFOHDQWHpRFDUERQHWR2FUHVFLPHQWRFRRSHUDWLYRGDVODPHODVID]VHVHPUHODomR FULVWDORJUi¿FDFRPDIDVHPmHDXVWHQtWLFD2HVSDoDPHQWRLQWHUODPHODUGLPLQXLFRPD WHPSHUDWXUDFRQGX]LQGRDPLFURHVWUXWXUDVPXLWR¿QDVSDUDYDORUHVGH7LVLWXDGRVQD]RQD LQIHULRUGRGRPtQLRSHUOtWLFR3RUFRQVHJXLQWHRFRQVWLWXLQWHIRUPDGRWHPXPDGXUH]D WDQWRPDLVHOHYDGDTXDQWRPDLVEDL[DIRUDWHPSHUDWXUDGHIRUPDomR7L$WUDQVIRUPDomR SHUOtWLFDID]LQWHUYLULPSRUWDQWHVIHQyPHQRVGHGLIXVmRGRFDUERQRHGRVHOHPHQWRVGH OLJDHPVXEVWLWXLomRQDDXVWHQLWH2VFDUERQHWRVIRUPDGRVVmRTXHUFHPHQWLWHVOLJDGDV TXHUFDUERQHWRVOLJDGRVSDUDRVHOHPHQWRVPDLVFDUERUtJHQRV 7UDQVIRUPDo}HVEDLQtWLFDV ¬PHGLGDTXH7LEDL[DDGLIXVmRGRVHOHPHQWRVHPVXEVWLWXLomRWRUQDVHPDLVGLItFLO HDWUDQVIRUPDomRSHUOtWLFDpSURJUHVVLYDPHQWHVXEVWLWXtGDSRUXPDQRYDWUDQVIRUPD omRGLWDEDLQtWLFD1DWUDQVIRUPDomREDLQtWLFDDIDVHQXFOHDQWHpDIHUULWH)RUPDVH SRUFRUWHGDUHGHGHDXVWHQLWHSRUJHUPLQDomRVHJXQGRSODQRVRFWDpGULFRVGDDXV WHQLWHHH[LVWHPUHODo}HVFULVWDORJUi¿FDVGRWLSR.XUGMXPRYH6DFKV>^`$ ^`) !$ !)@2VFDUERQHWRVIRUPDGRVVmRHVVHQFLDOPHQWHFDUERQHWRVGHIHUURR FDUERQRVHQGRR~QLFRHOHPHQWRTXHWHPXPFRH¿FLHQWHGHGLIXVmRVX¿FLHQWHPHQWH HOHYDGR'LVWLQJXHPVHGRLVWLSRVSULQFLSDLVGHEDLQLWH1D]RQDVXSHULRUGRGRPtQLR EDLQtWLFR EDLQLWHVXSHULRU DIHUULWHIRUPDVHHPµULSDV¶HDVSODTXHWDVGHFDUERQH WRVGHIHUURSUHFLSLWDPHQWUHHVVDVULSDVDSUR[LPDGDPHQWHSDUDOHODVDHODV )LJXUD D $SUHVHQoDHQWUHULSDVGDIDVHFDUERQHWRIUiJLOFRQIHUHjEDLQLWHVXSHULRUPiV FDUDFWHUtVWLFDVGHUHVLOLrQFLD

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


CAPรTULO 2

69

Aร‡OS

GDSHoDGDH[LVWrQFLDGHIHQyPHQRVH[RRXHQGRWpUPLFRVDTXDQGRGDVWUDQVIRUPDo}HV GHIDVHVPDVWDPEpPGRSRGHUGHDUUHIHFLPHQWRGRร€XLGRGHWrPSHUD$LPSRUWkQFLD SUiWLFDGRFRQKHFLPHQWRGDVOHLVGHDUUHIHFLPHQWRH[SOLFDRHVIRUoR WDQWRWHyULFRFRPR H[SHULPHQWDO SDUDIRUQHFHUDRXWLOL]DGRUGDGRVWmRSUHFLVRVTXDQWRSRVVtYHOVREUHHVWH SUREOHPD2VUHVXOWDGRVDSUHVHQWDPVHVREGLYHUVDVIRUPDVYiOLGDVSDUDWRGDVDVFODVVHV QmROLJDGDVRXIUDFDPHQWHOLJDGDVSDUDDVTXDLVRVYDORUHVGDVFRQGXWLYLGDGHVWpUPLFDV VmRSRXFRGLIHUHQWHV&XUYDVGHDUUHIHFLPHQWRSDUDIRUPDVVLPSOHVHGLYHUVRVPHLRVVmR UHSUHVHQWDGDVQDVPHVPDVFRRUGHQDGDVTXHDVFXUYDV75&$)LJXUDGiRH[HPSOR GHOHLVGHDUUHIHFLPHQWRDRyOHRSDUDYHLRV7DPEpPH[LVWHPFXUYDVVHPHOKDQWHVSDUD DiJXDHSDUDRDU

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

$VXSHUSRVLomRGHWUDQVSDUHQWHVDRVGLDJUDPDV75&SHUPLWHGHWHUPLQDUDVGXUH]DVDSyV WrPSHUDHDFRQVWLWXLomRGRDoR$)LJXUDPRVWUDWDODSOLFDomRSDUDRDoR&U3RU H[HPSORSRGHVHREVHUYDUTXHRDoRWHPSHUDSDUDYHLRVGHHPP8PYHLRFRPXP GLkPHWURGHPPยฟFDUHFR]LGR'HVSUH]DVH$UHVQHVVDVHVWLPDWLYDV3URFHGHQGRGHVWH PRGRSRGHVHHPSULQFtSLRGHWHUPLQDURWUDWDPHQWRWpUPLFRQHFHVViULR HVFROKDGR PHLRGHWrPSHUD SDUDFDUDFWHUtVWLFDVDSyVWrPSHUDยฟ[DGDVSDUDXPDSHoDGHGLPHQV}HV HGHFODVVHFRQKHFLGDV1RHQWDQWRHVWHPpWRGRpEDVWDQWHOLPLWDGRHHPERUDFRQVWLWXD


2.4.7.4. Diâmetro crítico

MATERIAIS DE CONSTRUÇÃO

80

PARTE A: METAIS

2GLkPHWURFUtWLFR SDUDXPGDGRPHLRGHDUUHIHFLPHQWR pDTXHOHDSDUWLUGRTXDOGHL[D GHDSDUHFHUQRQ~FOHRGDSHoDXPD]RQDFRPGXUH]DLQIHULRUDGHPDUWHQVLWH )LJXUD   FRQVLGHUDQGRTXHGHPDUWHQVLWHUHSUHVHQWDXPDHVWUXWXUDQmRWHPSHUDGD  $GHWHUPLQDomRGRGLkPHWURFUtWLFRHVWiDVVRFLDGDjVFXUYDVGHSHQHWUDomRGHWrPSHUD XPDYH]TXHDGXUH]DGHYHVHUPHGLGDDRORQJRGDVHFomRGHFDGDGLkPHWURWDOFRPR QDGHWHUPLQDomRGDVFXUYDVHP8FRPRPRVWUDGRQD)LJXUD$WHPSHUDELOLGDGH DXPHQWDFRPRGLkPHWURFUtWLFR(VWHPpWRGRpPXLWRPRURVRGHYLGRjVYiULDVPHGLo}HV GHPLFURGXUH]DHRGLkPHWURFUtWLFRGHSHQGHGRPHLRGHDUUHIHFLPHQWR

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

2.4.7.5. Utilização do ensaio Jominy 2HQVDLR-RPLQ\WHPSRUREMHWLYRDREWHQomRQXPDVyRSHUDomRHQXPSURYHWHQRUPDOL ]DGRGHLQGLFDo}HVJOREDLVVREUHDWHPSHUDELOLGDGHGHXPDoR(VWHHQVDLRHVWiGHVFULWR QDQRUPDSRUWXJXHVD13eUHDOL]DGRHPWUrVHWDSDV ¾ DXVWHQLWL]DomRGHXPSURYHWHPDTXLQDGRQRDoRDWHVWDUHGHGLPHQV}HVQRUPD OL]DGDV )LJXUD $WHPSHUDWXUDGHDXVWHQLWL]DomRGHSHQGHGRWLSRGHDoRH RWHPSRGHDXVWHQLWL]DomRpGHPLQ ¾ DUUHIHFLPHQWRQDSRQWDSRUXPMDWRGHiJXDHPFRQGLo}HVLPSRVWDV


4.2.1. Latões (ligas Cu-Zn, 5 a 45% de Zn) 2VODW}HVFRQWrPHQWUHDGH]LQFRHHYHQWXDOPHQWHRXWURVHOHPHQWRVHPPDLV EDL[DV SURSRUo}HV SDUD PHOKRUDUHP SURSULHGDGHV HVSHFt¿FDV 3RVVXHP XPD FRU TXH YDLGRURVDGRDRDPDUHORFRPXPWHRUHP]LQFR FUHVFHQWHR TXHOLJDGRDXPDERD UHVLVWrQFLDjFRUURVmRHXPDERDDSWLGmRDRVWUDWDPHQWRVGHVXSHUItFLHSHUPLWHUHDOL]DU SHoDVGHDJUDGiYHODVSHWR3RGHPVHUIXQGLGRVWUDEDOKDGRVDIULRRXDTXHQWHVHJXQGR DVXDFRPSRVLomR6mRIDFLOPHQWHHVWDPSDGRVHPEXWLGRVRXPDTXLQDGRV$7DEHOD DSUHVHQWDDFRPSRVLomRSURSULHGDGHVHDSOLFDo}HVGHDOJXPDVOLJDVGHFREUH

MATERIAIS DE CONSTRUÇÃO

136

/DWmRGH FDUWXFKRV

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/DWmRGH 0XQW]

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6Q3

&XSUR DOXPtQLR &XSUR QtTXHO

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5HVLVWrQFLDj GHIRUPDomR SOiVWLFD 03D

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(QGXUHFLGRSRU ± SUHFLSLWDomR HVWUXWXUDO 5HFR]LGR  (QFUXDGRDIULR  +GXUR

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5HFR]LGR  (QFUXDGRDIULR  +GXUR

5HFR]LGR  (QFUXDGRDIULR  5HFR]LGR  (QFUXDGRDIULR  +GXUR

/LJDVYD]DGDV /DWmRDR =Q3E %UXWRGH FKXPER 6Q YD]DPHQWR %UXWRGH YD]DPHQWR %UXWRGH YD]DPHQWR

± ±

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&RPSRVLomR PiVVLFD GRVHOHPHQWRV GHOLJD

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(VWDGR HVWUXWXUDO

PARTE A: METAIS

1RPHGDOLJD

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

)LRHOpWULFRUHELWHVMXQWDVSDQHODVSUHJRV WHOKDGRV 0RODVSLQRVGHGLVSDUREXFKDVYiOYXODV GLDIUDJPDV 1~FOHRVGHUDGLDGRUGHDXWRPyYHLV FRPSRQHQWHVGHPXQLo}HVGLVSRVLWLYRV HOpWULFRVGHOkPSDGDVURGDSpV 3DUDIXVRVHSRUFDVYDUDVGHEUDVDJHPSOD FDVGHFRQGHQVDGRUWXERVGHSHUPXWDGRUHV GHFDORUSHoDVIRUMDGDVDTXHQWH )ROHVGLVFRVGHHPEUDLDJHPGLDIUDJPDV IXVtYHLVFOLSVPRODV +pOLFHVPDULQKDVSiVGHWXUELQDV &RPSRQHQWHVGHFRQGHQVDGRUHVH SHUPXWDGRUHVGHFDORUWXEXODo}HVGHiJXD VDOJDGD )HUUDJHQVGHPyYHLVFRPSRQHQWHV GHUDGLDGRUHVFRPSRQHQWHVGHyWLFDV EUDoDGHLUDVGHEDWHULD 5RODPHQWRVEXFKDVDQpLVGHSLVWmRFRP SRQHQWHVGHPiTXLQDVDYDSRUHQJUHQDJHQV 5RODPHQWRVHQJUHQDJHQVEXFKDVYiOYXODV

4.2.1.1. Latões simples (binários Cu-Zn) 6mRGHVFULWRVSHORGLDJUDPDGHHTXLOtEULRGD)LJXUD'LVWLQJXHPVHDVWUrVVROXo}HV VyOLGDVĮȕHȖ1RWHTXHDIDVHȕSRGHWUDQVIRUPDUVHQXPDIDVHȕ¶RUGHQDGDTXHpGXUD HIUiJLO2VODW}HVLQGXVWULDLVGLYLGHPVHHPGXDVFDWHJRULDV


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

$EDL[DULJLGH]QRHVWDGRLVRWUySLFR )LJXUD HVWiHVVHQFLDOPHQWHOLJDGDjGHQVLGDGH GDHQHUJLDGDVOLJDo}HVUHVSRQViYHLVSHODFRHVmRGDVFDGHLDV1RVPHWDLVHRXWURVPDWH ULDLVLQRUJkQLFRVDFRHVmRpDVVHJXUDGDSRUXPDUHGHWULGLPHQVLRQDOGHOLJDo}HVIRUWHV PHWiOLFDVLyQLFDVRXFRYDOHQWHV 1RVSROtPHURVVHQGRDVOLJDo}HVIRUWHVDRORQJRGD FDGHLDHIUDFDVSHUSHQGLFXODUPHQWHjVFDGHLDVHVWDVSRGHPIDFLOPHQWHGHVORFDUVHXPDV HPUHODomRjVRXWUDV1RHQWDQWRVHWRGDVDVFDGHLDVIRUHPSDUDOHODV ยฟEUDVRULHQWDGDVGH .(9/$5ยŠ SRODPLGDDURPiWLFD GHSROLHWLOHQRHWF DULJLGH]HDUHVLVWrQFLDQDGLUHomR GDVFDGHLDVpGDPHVPDRUGHPGHJUDQGH]DRXDWpVXSHULRUjGRVPHWDLV $ GHVLJQDomR GH SROtPHURV RX D FRQVLGHUDomR GD HVWUXWXUD TXtPLFD GH XP SROtPHUR DSDUWLUGRFRQKHFLPHQWRGRVHXQRPHpXPDiUHDTXHIUHTXHQWHPHQWHFDXVDJUDQGHV GLยฟFXOGDGHVDTXHPVHLQLFLDQRHVWXGRGHVWHVPDWHULDLV(VWHSUREOHPDWRUQDVHPDLV FRPSOH[RSHODYDULHGDGHGHGHVLJQDo}HVFRPHUFLDLVTXHVmRXVDGDVSDUDGHVFUHYHUFHUWRV SROtPHURV HJSROLDPLGD3$RX1</21ยŠ 1RFDVRGHSROtPHURVGHDGLomRRXQRV

CAPรTULO 10

235

ESTRUTURA

$EDL[DGHQVLGDGHGHXPPDWHULDOHVWiDFLPDGHWXGROLJDGDjPDVVDDWyPLFDGRVHOH PHQWRVTXHRFRPS}HP&RPRRVSROtPHURVVmRHVVHQFLDOPHQWHIRUPDGRVSRUiWRPRV OHYHVFRPRRFDUERQRRXRKLGURJpQLRVmRGRVPDWHULDLVPHQRVGHQVRVTXHH[LVWHP )LJXUDH)LJXUD 


2SHVRPROHFXODUPpGLRpGH┬┐QLGRFRPRDVRPDGHSURGXWRVGRSHVRPROHFXODUGHFDGD IUDomR0LPXOWLSOLFDGDSHORSHVRGHVVDIUDomR: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 8PDUHGHLGHDOpXPDUHGHQDTXDOWRGDVDVFDGHLDVVmRHODVWLFDPHQWHDWLYDVLHDVVH JXUDPDOLJDomRHQWUHGRLVQyVVHPTXHGRLVRXWURVQyVHVWHMDPOLJDGRVSRUPDLVGRTXH XPDFDGHLD


12.1.1. Extrusão

MATERIAIS DE CONSTRUÇÃO

316

PARTE C: POLÍMEROS

$H[WUXVmRpXPDWpFQLFDGHWUDQVIRUPDomRGRVWHUPRSOiVWLFRVTXHSHUPLWHREWHUHP FRQWtQXRREMHWRVDFDEDGRVRXVHPLSURGXWRVFRPXPDVHFomRFRQVWDQWH$H[WUXVmRpXP SURFHVVRFRQWtQXRQRTXDOXPSDUDIXVRIRUQHFHXPÀX[RFRQWtQXRGHSROtPHURµIXQGLGR¶ SDUDXPD¿HLUDTXHFRQIHUHDRSURGXWRXPDIRUPDSUpGHWHUPLQDGDDVGLPHQV}HVGR SURGXWRVROLGL¿FDGRHDUUHIHFLGRGHSHQGHP±SDUDDOpPGDIRUPDHGLPHQV}HVGD¿HLUD ±GDVFRQGLo}HVGHSURFHVVDPHQWRLQFOXLQGRRDUUHIHFLPHQWR*UkQXORVGHSROtPHURVmR LQWURGX]LGRVQXPSDUDIXVRVHP¿PTXHURGDGHQWURGHXPFLOLQGURDTXHFLGRFRPRVH PRVWUDQD)LJXUD

Figura 12.1. Esquema de uma extrusora.

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13.6.3.1. Crazing

MATERIAIS DE CONSTRUÇÃO

356

PARTE C: POLÍMEROS

0XLWRVSROtPHURVFRPRRSROLHWLOHQRRSROLSURSLOHQRHDSROLDPLGDWrPXPFRPSRU WDPHQWRVHPHOKDQWHDRYLVWRQDVHFomRDQWHULRUjWHPSHUDWXUDDPELHQWH2XWURVFRP XPDPDLRU7JFRPRRSROLHVWLUHQRVyWrPHVVHFRPSRUWDPHQWRDWHPSHUDWXUDVPDLV DOWDV¬WHPSHUDWXUDDPELHQWHHVVHVSROtPHURVURPSHPSHODIRUPDomRGHXPDJUDQGH TXDQWLGDGHGHSHTXHQDVIHQGDV FUD]LQJ FRPRPRVWUDGRQD)LJXUD$VSHTXHQDV IHQGDVWRUQDPRSROtPHUREUDQFRDFRQWHFHQGRSRUH[HPSORTXDQGRVHGREUDPSHoDVGH SOiVWLFRGHWRGRVRVGLDVFRPRWDPSDVGHHVIHURJUi¿FD$VSHTXHQDVIHQGDVPDUFDPR LQtFLRGDIUDWXUDSRUTXHSRXFRGHSRLVGDVXDIRUPDomRXPDIHQGDGHJUDQGHVGLPHQV}HV GHVHQYROYHVHOLJDQGRDVIHQGDVSHTXHQDVHSURSDJDQGRDWpjURWXUD

Figura 13.12. Rotura por crazing num polímero.

13.6.3.2. Bandas de corte (shear bands) 2VSROtPHURVTXHWrPXPDOLPLWDGDGXFWLOLGDGHHPWUDomRGHYLGRDRIHQyPHQRGHFUD]LQJ SRGHPQRHQWDQWRDSUHVHQWDUXPDHOHYDGDFDSDFLGDGHGHGHIRUPDomRjFRPSUHVVmR IRUPDQGREDQGDVGHFRUWH VKHDUEDQGV FRPRPRVWUDGRQD)LJXUD&DGDEDQGD FRUUHVSRQGHDXPDGHIRUPDomRGHFRUWH¬PHGLGDTXHDXPHQWDRQ~PHURGHEDQGDVD GHIRUPDomRWRWDOYDLWDPEpPDXPHQWDQGR


2 FRPSRUWDPHQWR j Ă&#x20AC;XrQFLD HP WUDomR D WHPSHUDWXUD FRQVWDQWH  GR SROLSURSLOHQR p DSUHVHQWDGRQD)LJXUD

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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‡รƒO

376

PARTE D: COMPร“SITOS

3RGHPWHUXPFRPSRUWDPHQWRDOWDPHQWHDQLVRWUySLFRHPSDUWLFXODURVGHUHIRUoRVXQL GLUHFLRQDLVMiTXHDVXDPDWUL]pPXLWRPHQRVUHVLVWHQWHHUtJLGDGRTXHDVยฟEUDV7HP KDYLGRUHFHQWHPHQWHDOJXPLQWHUHVVHQRVFRPSyVLWRVGHPDWUL]PHWiOLFDFRPRDOXPtQLR UHIRUoDGRFRPSDUWtFXODVGHFHUkPLFRRXWLWkQLRFRPยฟEUDV1RFDVRGRVFRPSyVLWRVGH PDWUL]PHWiOLFDRVDXPHQWRVGHUHVLVWrQFLDHGHULJLGH]QmRVmRVXEVWDQFLDLVVHQGRR FRPSRUWDPHQWRDDOWDWHPSHUDWXUDRXDVSURSULHGDGHVWULEROyJLFDVDVSULQFLSDLVPRWL YDo}HV2VFRPSyVLWRVGHPDWUL]PHWiOLFDDLQGDWrPSRXFDH[SUHVVmRDQtYHOLQGXVWULDO FRQWUDULDPHQWHDRVFRPSyVLWRVGHPDWUL]SROLPpULFD1RFDVRGRVFRPSyVLWRVGHPDWUL] FHUkPLFDDSURSULHGDGHTXHVHWHQWDPHOKRUDUpDWHQDFLGDGHPDVWDOยฑFRPRQRFDVR GRVFRPSyVLWRVFRPPDWUL]PHWiOLFDยฑRVHXGHVHQYROYLPHQWRDLQGDVHHQFRQWUDQXPD IDVHLQLFLDO

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).

e LPSRUWDQWH WHU HP FRQWD DV SURSULHGDGHV GD PDWUL] H GR UHIRUoR QD IRUPXODomR GH XP FRPSyVLWR 3URSULHGDGHV SDUWLFXODUPHQWH LPSRUWDQWHV VmR D ULJLGH] D UHVLVWrQFLD


15.1.1.2. Enrolamento filamentar 8PSURFHVVRPDLVDGDSWDGRSDUDDXWRPDWL]DUpRHQURODPHQWR¿ODPHQWDU )LJXUD  )LEUDVHPURYLQJSDVVDPSRUXPEDQKRGHUHVLQDHVmRHQURODGDVVREUHXPPDQGULOHP URWDomR2VSDUkPHWURVFUtWLFRVVmRDWHQVmRGD¿EUDDVXDLPSUHJQDomRHDJHRPHWULD GHHQURODPHQWR6mRREWLGDVSHoDVGHHOHYDGDTXDOLGDGHPDVDJHRPHWULDpOLPLWDGDD SHoDVWXEXODUHV

MATERIAIS DE CONSTRUÇÃO

398

PARTE D: COMPÓSITOS

Figura 15.1. Método de moldação manual.

Figura 15.2. Enrolamento filamentar.

15.1.1.3. Pultrusão &RPRQRHQURODPHQWR¿ODPHQWDUQDSXOWUXVmRDV¿EUDVVmRHPSULPHLUROXJDULPSUHJ QDGDVSRUXPEDQKRGHUHVLQDSDVVDQGRDVHJXLUSRUXPD¿HLUDFRPXPDGHWHUPLQDGD JHRPHWULD HP TXH D UHVLQD p FXUDGD )LJXUD   2 FRPSyVLWR p SX[DGR SRU URORV ORFDOL]DGRVDVHJXLUj¿HLUD8PVLVWHPDGHFRUWHQR¿QDOGRSURFHVVRSHUPLWHREWHUXP


SHUยฟOFRPRFRPSULPHQWRGHVHMDGR$VSHoDVSURGX]LGDVVmRPDLVVHPLSURGXWRVGRTXH SHoDVDFDEDGDVXPSRXFRjVHPHOKDQoDGRVPDWHULDLVPHWiOLFRVSURGX]LGRVSRUH[WUXVmR

Figura 15.4. Moldaรงรฃo por RTM.

399

2XWURPRGRGHLPSUHJQDomRFRQVLVWHHPLQMHWDUDUHVLQDQXPPROGHHPTXHDVยฟEUDV HVWmRMiHPSRVLomReXPSURFHVVRVHPHOKDQWHDRGHVFULWRSDUDRVSROtPHURVH[FHWX DQGRRIDFWRGHTXHQRFDVRGRFRPSyVLWRDVยฟEUDVMiHVWmRQDFDYLGDGHGRPROGH$ UHVLQDpLQMHWDGDSRUJUDYLGDGHRXSRUSUHVVmR8PPpWRGREDVWDQWHFRQKHFLGRpR5HVLQ 7UDQVIHU0RXOGLQJ 570 HPTXHDVยฟEUDVHVWmRQXPPROGHHDUHVLQDFRPXPDEDL[D YLVFRVLGDGHpLQMHWDGDVREEDL[DSUHVVmR$FXUDRFRUUHQRPROGHHYHQWXDOPHQWHFRP WHPSHUDWXUD2PROGHpJHUDOPHQWHGHPHWDORTXHSHUPLWHXPDERDWUDQVIHUrQFLDGH FDORUHDSRVVLELOLGDGHGHVHUXVDGRPXLWDVYH]HV$)LJXUDPRVWUDHVTXHPDWLFD PHQWHRSULQFtSLRGHIXQFLRQDPHQWRGR5702XWURSURFHVVRVHPHOKDQWHDR570pR 55,0 5HLQIRUFHG5HDFWLRQ,QMHFWLRQ0RXOGLQJ $GLIHUHQoDHQWUHRVGRLVUHVLGHQR IDFWRGHQR570DUHVLQDVHULQMHWDGDSUpFXUDGDHQTXDQWRTXHQRQR55,0RVGRLV FRPSRQHQWHV UHVLQDHHQGXUHFHGRU VmRPLVWXUDGRVUDSLGDPHQWHHLQMHWDGRVQRPROGH

CAPรTULO 15

15.1.1.4. Moldaรงรฃo por transferรชncia/injeรงรฃo de resina

FABRICAร‡รƒO DE COMPร“SITOS

Figura 15.3. Pultrusรฃo.


(16.2)

2PyGXORGRPHVPRPDWHULDOVROLFLWDGRSHUSHQGLFXODUPHQWHjV¿EUDV(F )LJXUDE  pPXLWRPHQRUVHQGRGDGRSRU (16.3)

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2VPyGXORV(FH(FSDUDXPFRPSyVLWRFRPGH¿EUDVXQLGLUHFLRQDLVVmREDVWDQWH GLIHUHQWHVSRUTXHRPDWHULDOpPXLWRDQLVRWUySLFR8VDQGRXPWHFLGRRXXPODPLQDGRFRP ¿EUDVDžH¿EUDVDžpSRVVtYHOREWHUXPFRPSyVLWRFRPRPHVPRPyGXORDžHDž )LJXUDF 1RHQWDQWRRPyGXORDžSHUPDQHFHEDVWDQWHEDL[R&RQVHJXHVHXPD TXDVHLVRWURSLDFRORFDQGRSUpLPSUHJQDGRVURGDGRVDžFRPRPRVWUDGRQD)LJXUDG

MATERIAIS DE CONSTRUÇÃO

410

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.


2 PHFDQLVPR GH IRUPDomR GR FLPHQWR HVWi HVTXHPDWLFDPHQWH UHSUHVHQWDGR QD )L JXUD$VSDUWtFXODVGHFLPHQWRVmRLQLFLDOPHQWHPLVWXUDGDVFRPiJXD )LJXUD D  $SyV  PLQXWRV LQLFLDVH D SUHVD (TXDomR   FRP D IRUPDomR GH XPDSHOtFXODJHODWLQRVDGHKLGUDWR &$+ jYROWDGRVJUmRV2VJUmRVยฟFDPDVVLP OLJDGRVQRVSRQWRVGHFRQWDFWRRULJLQDQGRXPDUHGHGHOLJDo}HVIUDFDVTXHFDXVDP XPDSHUGDGHSODVWLFLGDGH$VOLJDo}HVSDUWHPVHIDFLOPHQWHTXDQGRVmRPLVWXUDGDV PDVIRUPDPVHGHQRYRUDSLGDPHQWH2HQGXUHFLPHQWR (TXDo}HV  H 

 FRPHoDDSyVDSUR[LPDGDPHQWHKRUDV)RUPDPVHSURWXEHUkQFLDVQRUHYHVWLPHQWR GHJHOTXHFUHVFHPQXPDUHGHGHQVDGHSLFRVLUUDGLDQGRGDVSDUWtFXODVGHFLPHQWR FRPRXPRXULoRGRPDU(VVHVSLFRVVmRR&6+GDVHTXDo}HVGHHQGXUHFLPHQWR ยฌPHGLGDTXHDKLGUDWDomRFRQWLQXDRVSLFRVFUHVFHPJUDGXDOPHQWHSUHHQFKHQGRDV ]RQDVHQWUHRVJUmRVGHFLPHQWR$UHGHGHDJXOKDVLQWHUOLJDGDVDFDEDSRUVROLGLยฟFDU QXPDPDVVDUtJLGDHWHPDSURSULHGDGHGHDRFUHVFHUSHQHWUDUHOLJDUVHjVXSHUItFLH SRURVDGHWLMRORVGHSHGUDVRXGHEHWmRSUpYD]DGR

MATERIAIS DE CONSTRUร‡รƒO

420

PARTE D: COMPร“SITOS

(PSDtVHVFRPFOLPDIULRRDXPHQWRGHWHPSHUDWXUDGRFLPHQWRpXVDGRSDUDHYLWDUR FRQJHODPHQWRGDiJXD1RHQWDQWRSDUDJUDQGHVHVWUXWXUDVFRPREDUUDJHQVRDTXHFL PHQWRpSUREOHPiWLFRHGHYHPVHUXVDGRVWXERVGHDUUHIHFLPHQWRHPEHELGRVQREHWmR SDUDHYDFXDURFDORUTXHVmRGHL[DGRVQROXJDUDWXDQGRFRPRXPDHVSpFLHGHUHIRUoR

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

$V FpOXODV SULQFLSDLV FKDPDGDV µ¿EUDV¶ RX µWUDTXHtGRV¶  GD PDGHLUD HVWmR DOLQKDGDV D[LDOPHQWHVHQGRDRORQJRGHVWDGLUHomRTXHDPDGHLUDpPDLVUHVLVWHQWH$PDGHLUD FRQWpPDQpLVQDGLUHomRUDGLDOGHGLIHUHQWHVGHQVLGDGHVHPIXQomRGDVHVWDo}HV1R LQYHUQRHQRRXWRQRRFUHVFLPHQWRpOHQWRRTXHGiGHQVLGDGHVHOHYDGDV$PDLRUSDUWH GRFUHVFLPHQWRRFRUUHQRFDPELXPTXH¿FDPHVPRSRUEDL[RGDFDVFD$SDUWHUHVWDQWH GDPDGHLUDHVWiSUDWLFDPHQWHPRUWDWHQGRXPDIXQomRHVWUXWXUDOSDUDVHJXUDUDiUYRUH

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

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Materiais de Construção