Be对WE43镁合金高温氧化行为及阻燃性的影响

Effect of Be on Oxidation Behavior and Flame Retardancy of WE43 Mg-alloy at High-temperature

采用电磁搅拌工艺制备添加0.04%(质量分数)Be的WE43(WE43-0.04Be)镁合金。对固溶处理后的镁合金在225℃下进行了不同时间(6、10、 14 h)的时效处理。结果表明,时效处理10 h后合金拥有最佳的力学性能,抗拉强度为253 MPa,屈服强度达到209 MPa,延伸率为8.3%,可满足高速铁路结构件的力学性能要求。高温氧化实验结果表明,添加Be后合金在850℃的电阻炉中未燃。合金表面生成Mg与合金元素的混合氧化物层,从而抑制氧元素向合金内部扩散。

The cast WE43 Mg-alloy with addition of 0.04%Be(WE43-0.04Be)was prepared by electromagnetic stirring melting and casting process,and then subjected to solid solution treatment at 525oC for 10 h plus aging treatment at 225oC for 6,10 and 14 h,respectively.Afterwards,the microstructure,mechanical property,oxidation behavior and flame-retardant property were assessed for the prepared alloys.The results showed that the WE43-0.04Be alloy aged for 10 h possessed the best comprehensive performance,namely its tensile strength,yield strength and elongation were 253 MPa,209 MPa and 8.3%respectively,which could meet the mechanical property requirements for high-speed railway structural parts.The WE43-0.04Be alloy will not burn in air when heated up to 850oC in a furnace.A mixed oxide scale composed of compounds of Mg and alloying elements was generated on the surface of the alloy,thus inhibiting the inwards migration of aggressive species approching onto the interface oxide scale/WE43-0.04Be alloy.