Al-0.12Zr合金中Zr元素的添加方法研究

Research on adding methods of Zr in Al-0.12Zr alloy

采用不同Zr添加方法制备了4种Al-0.12Zr合金铸锭,计算了采用不同方法制备Al-0.12Zr合金铸锭时Zr元素的实收率,并利用体视显微镜和金相显微镜分别观察了合金铸态和均匀化处理后的低倍组织及合金热轧板经退火处理后的晶粒。研究结果表明:通过向760℃的铝液中添加Al-4Zr中间合金和复合锆盐方式制备Al-0.12Zr合金铸锭的方法,Zr元素的实收率分别为79%和77%,而通过向760℃和800℃的铝液中直接加入K2ZrF6制备Al-0.12Zr合金铸锭的方法,Zr元素的实际收率分别为35%和30%;添加0.12%的Zr能明显细化铝合金铸锭柱状晶晶粒和退火态板材的再结晶晶粒,且Al-0.12Zr退火板再结晶晶粒存在明显的混晶现象;Zr元素添加方法对铝合金铸态、均匀化处理后铸锭及退火态热轧板的晶粒形状和尺寸无明显影响;Al-0.12Zr合金铸锭经460℃保温24 h的均匀化处理后铸锭晶粒保持不变。

Four kinds of Al-0.12 Zr alloy ingots were prepared by different adding methods of Zr,and the actual yield rate of Zr element in alloy ingots with different methods were calculated.The macrostructure of as cast and homogenized alloy ingots,the grain of the hot-rolling alloy sheet after annealing treatment were observed by stereomicroscope and metallographic microscope,respectively.The results show that the actual yield rate of Zr in Al-0.12 Zr alloy ingot prepared by adding Al-4 Zr master alloy and composite zirconium salt to molten aluminum at 760℃are 79%and 77%,respectively.However,the actual yield rate of Zr in Al-0.12 Zr alloy ingot prepared by directly adding K2ZrF6to molten aluminum at 760℃and 800℃are 35%and 30%,respectively;The columnar grain of aluminum alloy ingot and the recrystallized grain of annealed aluminum alloy sheet can be obviously refined by the addition of 0.12%Zr,but the recrystallized grain of annealed aluminum alloy sheet are obvious mixed crystal.The addition method of Zr in Al-0.12 Zr aluminum alloy has no significant effect on the grain shape and size of aluminum alloy ingot in as cast and after homogenized treatment,annealed alloy sheet.Besides,the grain of Al-0.12 Zr alloy ingot remains unchanged after homogenization treatment at 460℃for 24 h.