| Micro-alloying is one of the effective ways to improve the aluminum alloy comprehensive performance. Different contents of Al-Sc-Zr, Al-Sc-Zr-Er alloys were prepared by adding trace Sc,Zr,Er elements into high purity aluminum. The mechanical properties were investigated through microhardness measurement, The condition of micro-alloying elements solute in matrix was characterized by conductivity measurements, The Optical microscope(OM) and transmission electron microscopy(TEM) were used to analysis microstructure of the alloys. To study the influence of Er elements to different Sc content of Al-Sc-Zr alloy mechanical properties and recrystallization behavior.The results of isochronal aging indicate that when the concentration of Sc is less than 0.04 at.%, The hardness of Al-Sc-Zr alloy can be increased by an average of 10 HV after adding Er, The lower Er concentration, the more obvious the effect of Sc. When the concentration of Sc is greater than 0.04 at.%, The peak hardness of Al-Sc-Zr alloy is basically unchanged after adding Er.The results of isothermal aging indicate that 300? aging,When the Sc content is less than 0.045 at.%, The average hardness of quaternary alloy can be increased 6HV compared with ternary alloy, The effect of Er is obvious. When the content of Sc is more than 0.045 at.%, the peak hardness of Al-Sc-Zr-(Er) alloy is not quite different. 350? aging, When the content of Sc is less than 0.12 at.%, the average peak hardness of Al-Sc-Zr can be increased by 12 HV, but with the increase of Sc concentration, the difference between the two is decreased, and the effect of Er is less and less obvious. 400? aging, when the Sc content is less than 0.12 at.%, The addition of Er can increase the peak hardness of Al-Sc-Zr by 20 HV, When the Sc content is 0.176 at.%, Er has little influence on the peak hardness of Al-Sc-Zr alloy. 450? aging, When the concentration of Sc is between 0.016 at.%~0.12 at.%, The addition of Er can increase the hardness value of the alloy by 18 HV, When the concentration of Sc is 0.176 at.%, only increases 5.6HV, The effect of Er on the hardness of the alloy is small.The effect of aging temperature on Er indicate that when aging at different temperatures, for high Sc(0.176 at.%) content alloy, Er has little influence on the peak hardness of the alloys, For low Sc(0.016 at.%) content alloy, Er can significantly increase the peak hardness of the alloy; For the middle Sc(0.047 at.%~0.12 at.%) content alloy, the role of Er is more and more obvious.The result of recrystallization research indicate that The recrystallization starting temperature of Al-0.016Sc-0.061 Zr alloy is 450?, At the same time, The recrystallization starting temperature of Al-0.009Sc-0.054Zr-0.014 Er alloy is 500?, So the recrystallization temperature of Al-0.016Sc-0.061 Zr alloy can be increased by 50 ? when 0.01 at.% Sc element is replaced by the same content Er. Al-0.047Sc-0.073 Zr and Al-0.045Sc-0.056Zr-0.011 Er alloy do not occur recrystallization phenomenon at 525?. To judge the role of Er, it is necessary to observe the microstructure of the higher temperature. For Al-0.085Sc-0.063 Zr and Al-0.074Sc-0.064Zr-0.01 Er alloys, The recrystallization annealing curve is almost coincident, using 0.01 at.% Er content replace of equivalent Sc, No recrystallization occurre after recrystallization annealing of 1h at 525?. Therefore, The addition of Er element has almost no effect on the recrystallization behavior of the ternary alloy. When the Sc content is more than 0.12 at.%, Recrystallization annealing temperature is not higher than 450?, using 0.01 at.% Er content replace of equivalent Sc, There is little effect on mechanical properties and recrystallization behavior of Al-Sc-Zr alloy. |
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