微重力电磁模拟制备高锂含量铝锂合金

Preparation of Al-Li Alloy Containing High Li by Micro-gravity Electromagnetic Force Simulation Facilities

采用普通熔炼工艺制备的铝锂合金 ,锂的质量分数不超过 3 % ,否则 ,合金会出现严重的偏析。利用电磁模拟微重力装置 ,将原料放入涂有BN的高纯石墨坩埚并装入炉中 ,抽真空到 10Pa开始对炉体加热 ,温度达到 3 0 0℃时充入氩气 ,使炉内压力维持在 40Pa ,合金温度达到 760℃时停止加热 ,保温 40min ,在电磁铁中输入励磁电流并在熔体中加入直流电场 ,温度降至凝固温度时去掉电磁场 ,冷却至室温 ,可以制备出锂的质量分数为 5 %～ 10 %的二元铝锂合金。试验证明

Li content in Al Li alloy prepared by conventional smelting process can't exceed 3%, otherwise serious segregation could occur in the alloy. Binary Al Li alloy containing (5～10)% Li can be prepared by using micro gravity electromagnetic force simulation facilities. The technological process adopted is discussed as follows: the Al ingot and Li stick set in the BN coated pure graphite crucible electric furnace begin to be heated when vacuated up to 10Pa and the furnace is charged with argon gas up to 40 Pa as continuing heating to 300 ℃. Then heating stops as melt temperature reaches to 760 ℃ with holding time for 40min. Meanwhile exciting electric current applies to ferromagnet and direct current applies to the melt. Finally the demagnetization was performed as melt temperature drops to solidification temperature with continuing air cooling. The experiment verifies that segregation of the alloy can be prevented by the techniques.