La对ADC12微观组织及耐腐蚀性能的影响
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摘要
采用光学显微镜、扫描电镜、能谱仪等研究了ADC12-xLa(x=0,0.3,0.6,0.9)合金的微观组织及腐蚀性能。结果表明,当La含量从0增加到0.6%时,ADC12合金中的初生α-Al、共晶Si和Al_8SiFe_2相会逐渐细化,且耐腐蚀性能逐渐提高。其原因是La含量低于0.6%时,La在变质过程中会吸附在共晶Si相表面,阻碍了腐蚀电子流动,使合金的耐腐蚀性能提高。而La含量达到0.9%时,合金中会生成大量的La-Al-Cu稀土相,该稀土相会与α-Al发生电偶腐蚀,导致ADC12-0.9La合金耐腐蚀性能降低。
The effects of La on the microstructure and corrosion behavior of ADC12-xLa(x=0,0.3,0.6,0.9)alloy were investigated by optical microscope(OM),scanning electron microscope(SEM)and energy disperse spectrometer(EDS).The results show that when La content is increased from 0 to 0.6%,the morphology of primaryα-Al,eutectic Si and Al_8SiFe_2 phases in the ADC12 alloy is refined gradually and the corrosion resistance is improved gradually.When rare earth La is less than 0.6%,it can be adsorbed at the surface of cathode phase during the modified process,thus forming a layer of rare earth oxidation film between the cathode and the anode.The rare earth oxidation film hinders the flow of corrosion electrons and improves the corrosion resistance of the ADC12 alloy.When the La content reaches 0.9%,a large amount of La-Al-Cu phases are generated in the alloy,which acts as a cathode phase in the alloy,resulting in the decrease of corrosion resistance of ADC12-0.9 La alloy.
The effects of La on the microstructure and corrosion behavior of ADC12-xLa(x=0,0.3,0.6,0.9)alloy were investigated by optical microscope(OM),scanning electron microscope(SEM)and energy disperse spectrometer(EDS).The results show that when La content is increased from 0 to 0.6%,the morphology of primaryα-Al,eutectic Si and Al_8SiFe_2 phases in the ADC12 alloy is refined gradually and the corrosion resistance is improved gradually.When rare earth La is less than 0.6%,it can be adsorbed at the surface of cathode phase during the modified process,thus forming a layer of rare earth oxidation film between the cathode and the anode.The rare earth oxidation film hinders the flow of corrosion electrons and improves the corrosion resistance of the ADC12 alloy.When the La content reaches 0.9%,a large amount of La-Al-Cu phases are generated in the alloy,which acts as a cathode phase in the alloy,resulting in the decrease of corrosion resistance of ADC12-0.9 La alloy.
引文
[1]HUANG Z X,YAN H,WANG Z W.Microstructure and mechanical properties of strontium-modified ADC12alloy processed by heat treatment[J].Journal of Central South University,2018,25(6):1 263-1 273.
[2]LIU W,YAN H,ZHU J B.Effect of the addition of rare earth element La on the tribological behaviour of AlSi5Cu1Mg alloy[J].Applied Sciences,2018,8(2):163-165.
[3]RAUL A,BEATRIZ M,PARDO A,et al.Pitting corrosion of rheocast A356aluminium alloy in 3.5%NaCl solution[J].Corrosion Science,2013,73(2):342-355.
[4]FATIH T,ALEXANDRA A,KERTI I,et al.Corrosion and tribocorrosion behaviour of Al-Si-Cu-Mg alloy and its composites reinforced with B4C particles in 0.05 mol/L NaCl solution[J].Wear,2013,306(1):27-35.
[5]VIEIRA A C,ANA M P,LUIS A R,et al.Effect of Al2Cu precipitates size and mass transport on the polarisation behaviour of agehardened Al-Si-Cu-Mg alloys in 0.05mol/L NaCl[J].Electrochimica Acta,2011,56(11):3 821-3 828.
[6]MILOSEV L,VOLARIC B.Conversion coatings based on rare earth nitrates and chlorides for corrosion protection of aluminum alloy 7075-T6[J].Corrosion,2017,73(7):822-843.
[7]GU B S,GONG L,YANG P Y.Study on performance and corrosion resistance mechanism of rare earth metal conversion coating on Al alloy surface[J].Rare Metal Materials and Engineering,2014,43(2):429-434.
[8]WANG C L,GAO Y.Effect of Y2O3addition on interface structure and corrosion resistance of laser additive manufacturing on the surface of Al alloys[J].Rare Metal Materials and Engineering,2017,46(3):812-817.
[9]WANG K L,ZHANG Q B,SUN M L,et al.Microstructure and corrosion resistance of laser clad coatings with rare earth elements[J].Corrosion Science,2001,43(2):260-267.
[10]ZHANG X,WANG Z H,ZHOU Z H,et al.Effects of magnetic field and rare earth addition on corrosion behavior of Al-3.0Mg alloy[J].Journal of Alloys and Compounds,2017,698:241-249.
[11]WANG Y,GUPTA R K,SUKIMAN N L,et al.Influence of alloyed Nd content on the corrosion of an Al-5Mg alloy[J].Corrosion Science,2013,73:181-187.
[12]CARDINALEA A M,MACCID,LUCIANO G,et al.Thermal and corrosion behavior of as cast Al-Si alloys with rare earth elements[J].Journal of Alloys and Compounds,2016,695:2 180-2 189.
[13]MAO F,YAN G Y,XUAN Z J,et al.Effect of Eu addition on the microstructures and mechanical properties of A356aluminum alloys[J].Journal of Alloys and Compounds,2015,650:896-906.
[14]LI Z H,YAN H,HU Z,et al.Fluidity of ADC12+xLa aluminum alloys[J].Rare Metals,2014(9):1-7.
[15]HUANG X,YAN H.Effect of trace La addition on the microstructure and mechanical property of as-cast ADC12Al-alloy[J].Journal of Wuhan University of Technology,2013,28(1):202-205.
[16]TAKEUCHI A,INOUE A.Classification of bulk metallic glasses by atomic size difference,heat of mixing and period of constituent elements and its application to characterization of the main alloying element[J].Materials Transactions,2005,46(12):2 817-2 829.
[17]JING L J,PAN Y,LU T,et al.Application of Al-2La-1Bgrain refiner to Al-10Si-0.3Mg casting alloy[J].Journal of Materials Engineering and Performance,2018,27(6):2 838-2 843.
[18]RAUL A,BEATRIZ M,PARDO A,et al.Microstructure and corrosion behaviour of A356aluminium alloy modified with Nd[J].Mater.Corrosion,2015,66(6):535-541.
[2]LIU W,YAN H,ZHU J B.Effect of the addition of rare earth element La on the tribological behaviour of AlSi5Cu1Mg alloy[J].Applied Sciences,2018,8(2):163-165.
[3]RAUL A,BEATRIZ M,PARDO A,et al.Pitting corrosion of rheocast A356aluminium alloy in 3.5%NaCl solution[J].Corrosion Science,2013,73(2):342-355.
[4]FATIH T,ALEXANDRA A,KERTI I,et al.Corrosion and tribocorrosion behaviour of Al-Si-Cu-Mg alloy and its composites reinforced with B4C particles in 0.05 mol/L NaCl solution[J].Wear,2013,306(1):27-35.
[5]VIEIRA A C,ANA M P,LUIS A R,et al.Effect of Al2Cu precipitates size and mass transport on the polarisation behaviour of agehardened Al-Si-Cu-Mg alloys in 0.05mol/L NaCl[J].Electrochimica Acta,2011,56(11):3 821-3 828.
[6]MILOSEV L,VOLARIC B.Conversion coatings based on rare earth nitrates and chlorides for corrosion protection of aluminum alloy 7075-T6[J].Corrosion,2017,73(7):822-843.
[7]GU B S,GONG L,YANG P Y.Study on performance and corrosion resistance mechanism of rare earth metal conversion coating on Al alloy surface[J].Rare Metal Materials and Engineering,2014,43(2):429-434.
[8]WANG C L,GAO Y.Effect of Y2O3addition on interface structure and corrosion resistance of laser additive manufacturing on the surface of Al alloys[J].Rare Metal Materials and Engineering,2017,46(3):812-817.
[9]WANG K L,ZHANG Q B,SUN M L,et al.Microstructure and corrosion resistance of laser clad coatings with rare earth elements[J].Corrosion Science,2001,43(2):260-267.
[10]ZHANG X,WANG Z H,ZHOU Z H,et al.Effects of magnetic field and rare earth addition on corrosion behavior of Al-3.0Mg alloy[J].Journal of Alloys and Compounds,2017,698:241-249.
[11]WANG Y,GUPTA R K,SUKIMAN N L,et al.Influence of alloyed Nd content on the corrosion of an Al-5Mg alloy[J].Corrosion Science,2013,73:181-187.
[12]CARDINALEA A M,MACCID,LUCIANO G,et al.Thermal and corrosion behavior of as cast Al-Si alloys with rare earth elements[J].Journal of Alloys and Compounds,2016,695:2 180-2 189.
[13]MAO F,YAN G Y,XUAN Z J,et al.Effect of Eu addition on the microstructures and mechanical properties of A356aluminum alloys[J].Journal of Alloys and Compounds,2015,650:896-906.
[14]LI Z H,YAN H,HU Z,et al.Fluidity of ADC12+xLa aluminum alloys[J].Rare Metals,2014(9):1-7.
[15]HUANG X,YAN H.Effect of trace La addition on the microstructure and mechanical property of as-cast ADC12Al-alloy[J].Journal of Wuhan University of Technology,2013,28(1):202-205.
[16]TAKEUCHI A,INOUE A.Classification of bulk metallic glasses by atomic size difference,heat of mixing and period of constituent elements and its application to characterization of the main alloying element[J].Materials Transactions,2005,46(12):2 817-2 829.
[17]JING L J,PAN Y,LU T,et al.Application of Al-2La-1Bgrain refiner to Al-10Si-0.3Mg casting alloy[J].Journal of Materials Engineering and Performance,2018,27(6):2 838-2 843.
[18]RAUL A,BEATRIZ M,PARDO A,et al.Microstructure and corrosion behaviour of A356aluminium alloy modified with Nd[J].Mater.Corrosion,2015,66(6):535-541.