【材料课件】第八章材料与环境(共4学时)(彩色版)

18.1M→Mn++ne−O2+2H2O+4e−→4(OH)−M+Cl−+H2O→MOH+2Cl−+H+Cl-Cl-Cl-Cl-Cl-Cl-Cl-Cl-M+M+M+M+M+OH-OH-O2Na+Na+O2O2O2O2O2eeNa+Na+H+H+H+H+Cl-Cl-Cl-Cl-Cl-Cl-Cl-Cl-Cl-Cl-M+M+M+M+M+M+M+M+M+M+M+M+M+Cl-H+Cl-OH-OH-OH-OH-OH-O2Na+Na+O2O2O2O2O2O2eeeM→Mn++ne−O2+2H2O+4e−→4(OH)−Fe2++2H2O+2Cl−→Fe(OH)2+2HCl~µ2Cr23C6SelectiveleachingAAAAAAABBBBBBA-BA-BA-BA-BA-BAM+½O2MOMM2++2e½O2+2eO2babaOMO2M2→+8.23-M→Mn++ne-O2+4e→2O2(a)(b)(c)(d)O2Metaly=oxidethicknessMetalMetalMetalMn+ne2O24eMn+2O2(4+n)e1Cdtdy=y=C1t+C2LineargrowthratelawFickyCdtdy13=y2=C4t+C5ParabolicgrowthratelawydtdyyJyCDxcDJOO1122∝∝∴∆−=∂∂−=−−xy∆c100nm°Clogarithmicgrowthratelawy=c6In(c7t+1)yy0t00LinearParabolicLogarithmicPilling-BedworthRatiooxidemetalmetaloxidedaMdMR=MaObProtectiveoxidesNonprotectiveoxidesBe1.59Li1.57Cu1.68Na1.57Al1.28K1.45Si2.27Ag1.59Cr1.99Cd1.21Mn1.79Ti1.95Fe1.77Mo3.40Co1.99Hf2.61Ni1.52S2.35Pd1.60W3.40P1.40Ta2.33Ce1.16U3.05V3.18Pilling-BedworthRatiosforVariousMetalOxides4t=0100nm,600°C1200nmSOLUTIONy2=c4t+c5t=0,y=100nm,(100nm)2=c4(0)+c5C5=104nm2SAMPLEPROBLEMt=24h,y2=3×104nm2/h(24h)+104nm2=73×104nm2y=854nm(=0.854µm)t=1h,y=200nm,(200nm)2=c4(1h)+104nm2C4=3×104nm2/hCu2O6.00Mg/m3,Pilling-edworth.SOLUTIONPilling-BedworthoxidemetalmetaloxidedaMdMR=68.1)00.6)(55.63)(2()93.8](16)55.63(2[=+=RSAMPLEPROBLEM8.3ZincZnH+H+AcidsolutionH2eeZnZn2++2e2H++2eH2MMn++neFeFe2++2eAlAl3++3e52H++2eH2O2+4H++4e−2H2OO2+2H2O+4e−4(OH)Fe3++e−Fe2+0.780VVVoltmeterFeCuFe2+Cu2+Fe2+solution1.0MCu2+solution1.0Mee0.323VVVoltmeterZnZn2+FeFe2+Fe2+solution1.0MZn2+solution1.0MeeFeFe2+eePtO2+2H2O+4e−→4(OH)Fe2++2OH-→Fe(OH)22Fe(OH)2+H2O+½O2→2Fe(OH)3VVoltmeterPtH+solution1.0MHydrogengas1atmpressureMembraneElectrodeReactionStandardElectrodePotential(V0)(V)Au3++3e-→Au+1.420O2+4H++4e-→2H2O+1.229Ni2++2e-→Ni-0.250Pt2++2e-→Pt~+1.2Co2++2e-→Co-0.277Ag++e-→Ag+0.800Cd2++2e-→Cd-0.403Fe3++e-→Fe2++0.771Fe2++2e-→Fe-0.440O2+2H2O+4e-→4(OH-)+0.401Cr3++3e-→Cr-0.744Cu2++2e-→Cu+0.340Zn2++2e-→Zn-0.7632H++2e-→H20.000Al3++3e-→Al-1.662Pb2++2e-→Pb-0.126Na++e-→Na-2.714Sn2++2e-→Sn-0.136K++e-→K-2.9246Fe2++2e-→Fe-0.440Cu2++2e-→Cu+0.3400.340-(-0.440)=0.780VFe2++2e-→Fe-0.440Zn2++2e-→Zn-0.763:-0.763-(-0.440)=-0.323V:-0.440-(-0.763)=+0.323VNernst]M[]M[log)(210102++−−=∆nnnFRTVVVF-Faraday96,500C/mol]M[]M[log0592.0)(210102++−−=∆nnnVVVT=25°CM1n+=M2n+=1∆V=(V20-V10)Fe→Fe2++2e−O2+2H2O+4e−→4(OH)−eO2O2O2Fe→Fe2++2e−Fe2++2e−→FeeFe2+Fe2+Fe2+Fe2+ee78.4AtKWρ=CPRWtρAKK=87.6CPRmm/yr0.5mm/yrCorrosionPenetrationRatenFir=96500C/molMol/m2-sZnZn2+Zn2+solution1.0MH+solution1.0MePt2H+H2H2gas1atmMembraneη=−0.621-(-0.736)=+0.142VActivationPolarizationH+H+HH2HH+1234312ZincH+H2H2H2H2ee1.H+2.H++e→H3.2H→H24.0logiiaβη±=i02H++2e→H2rred.H2→.2H++2eroxid.rred=roxidnFirroxidred0==80.0010.010.11101001000+β–βH2→2H++2e-2H++2e-→H2i0(H2/H+)ηa(V)+0.2+0.10–0.1–0.2–0.3ConcentrationPolarizationH+H+H+H+H+H+H+H+H+H+H+H+H+H+H+H+H+H+H+H+H+H+H+H+H+H+H+CathodeCathode−=LciinFRT1lnηiL+0OvervoltageηcLogcurrentdensityii00+η10-1210-1010-810-610-410-21i0(H+/H2)V(H+/H2)2H++2e→H2VCV(Zn/Zn2+)Zn→Zn2++2ei0(Zn/Zn2+)VV+0.4+0.20.00–0.2–0.4–0.6–0.8–1.0i(A/cm2)iCi0(H+/H2)V(H+/H2)VCV(M/M2+)i0(M/M2+)iCViL9Zn+2H+→Zn2++H2(a)(mol/cm2-s)ForZnForHV(Zn/Zn2+)=-0.763VV(H+/H2)=0Vi0=10-7A/cm2io=16-10A/cm2β=+0.09β=-0.08(b)EXAMPLEPROBLEMa)0logiiaβη±=SOLUTION+=+H0H)/HH(Hlog2iiVVβ+=+Zn0Zn)Zn/Zn(Znlog2iiVVβVH=VZn+=+++Zn0Zn)(Zn/ZnH0H)/HH(loglog22iiViiVββiC924.3)]10)(log09.0()10)(log08.0()0763.0(0[)08.0(09.01]loglog[1log710Zn0ZnH0H)(Zn/Zn)/HH(HZn22−=+−−−−−−=+−−−=−−++iiVViCββββ24924.3A/cm1019.110−−×==CinFir=smol/cm1017.6C/mol)96500(2cmC/s1019.121024⋅×=×⋅×==−−nFirVViiVV486.0A/cm10A/cm1019.1log)08.0(0log210-24H0H)/HH(C2−=×−+=+=−+βiC,VHVZnVC0.763V10V(M/M2+)i0(M/M2+)VM→M2++2eTranspassivePassiveActivei0(M/M2+)i0(1)i0(2)iC(B)iC(A)21BAV1.:2.3.8.5(a)(b)(c)()(d)()11(g)()(f)()()(h)(i))Mg+()GalvanicProtectionZn2+Zn2+Zn2+Zn2+eeee128.61“”2PMMATh°CK350%/min5090.00000524320.0024140.0043870.0693275.2260170300nm330~400nm350nm82kcal/molnmkcal/molOO0.13235SiSi0.23542.5SS0.19~0.2164CN0.14773CCl0.17781CC0.15483CO0.14686NH0.10193CH0.11099CF0.132~0.139103~123OH0.096111CC0.134146CO0.121179CN0.115213−CH−N−−CH2−CH−−Si−O−−CH2−CH2−−CH2−CH−ClH−CH=CH−−CH−N−H=OCH3CH3−CH2−OH−CH2O−−CH2−S−S−C−O−=O−CF2−CF2−−CH2−C−RR13α