微量Sc和Zr对Al-Mg-Mn合金组织与力学性能的影响

摘要

Both AI-5.8Mg-0.4Mn and Al-5.8Mg-0.4Mn-0.25Sc-0.1Zr (mass fraction, %) alloy ingots were prepared using water chilling copper mould ingot metallurgy processing protected by active flux. The alloy ingots were finally rolled into 2 mm-thick sheets after hot rolling-intermediate annealing-cold rolling. The effects of stabilizing annealing and minor Sc, Zr on the microstructure and mechanical properties of Al-Mg-Mn alloys were studied. The results show that after adding minor Sc and Zr into Al-Mg-Mn alloy simultaneously a large number of Al3(Sc, Zr) particles dispersedly distribute in the matrix, which have function of strongly pinning sub-grain boundaries and dislocations. The anti-recrystallization ability and the mechanical properties of the Al-Mg-Mn-Sc-Zr alloy sheet are significantly improved. By annealing at 300 'C for 1 h, the Al-Mg-Mn-Sc-Zr alloy sheet can obtain the optimum application values of 0b,00.2 and S, which are 436 MPa, 327 MPa and 16.7%, respectively.%采用活性熔剂保护熔炼、水冷铜模激冷铸造制备Al-5.8Mg-0.4Mn和Al-5.8Mg-0.4Mn-0.25sc-0.1Zr(质量分数,％)两种合金铸锭.合金铸锭经热轧-中间退火-冷轧成2 mm薄板；研究稳定化退火及微量Sc和Zr对Al-Mg-Mn合金组织与性能的影响.结果表明:在Al-Mg-Mn合金中加入微量Sc和Zr后形成大量弥散的Al3(Sc,Zr)粒子,这些粒子对位错和亚晶界具有强烈的钉扎作用,能明显提高合金的抗再结晶能力和室温力学性能；Al-Mg-Mn-Sc-Zr合金板材经300℃退火1h后可获得最佳综合力学性能,其σb、σ0.2与δ分别为436 MPa、327 MPa 和16.7％.