Ca对Mg-6Al-1Nd合金显微组织和性能的影响

为了研究Ca元素对Mg-6Al-1Nd合金微观组织、力学性能和阻燃性能的影响规律,采用了金属型重力铸造方法制备了Mg-6Al-1Nd-x Ca合金.通过金相显微镜、扫描电镜、万能拉伸试验机和热分析仪等分析测试手段对Mg-6Al-1Nd-x Ca合金的显微组织、力学性能和阻燃性能进行了表征.结果表明:Ca元素的加入可减少β-Mg17Al12含量,生成Al-Ca金属间相;随着Ca质量分数的增加,镁合金试样中的Al-Ca金属相增多,试样的室温抗拉强度和延伸率降低,阻燃性能升高;不含Ca元素的Mg-6Al-1Nd合金的抗拉强度为235 MPa,当Ca元素增加到2.5%时,Mg-6Al-1Nd-2.5Ca合金的抗拉强度仅为154 MPa,但该合金的着火点可达850℃.

Effect of Ca on the Microstructure and Properties of Mg-6Al-1Nd Alloy

The Mg-6Al-1Nd-xCa alloys were fabricated by gravity method with permanent mould in order to study the effect of Ca on microstructure,mechanical properties and ignition proof property of Mg-6Al-1Nd alloy.The microstructure,mechanical properties and ignition proof property of Mg-6A-1Nd-xCa alloys were characterized by optical microscope,scanning electron microscope,universal tensile testing machine and thermal analyzer.The β-Mg17Al12phase decreases and Al-Ca intermetallic phase produces with addition of Ca in Mg-6Al-1Nd-xCa alloys.With the increasing of Ca,the Al-Ca intermetallic phase increases,the ultimate tensile strength and elongation of Mg-6Al-1Nd-xCa alloys sample decrease and the ignition proof property is improved.The value of ultimate tensile strength of Mg-6Al-1Nd alloy is 235 MPa,and when the Ca content is 2.5wt.％,the alue of ultimate tensile strength of Mg-6Al-1Nd-2.5Ca alloy is only 154 MPa,but the ignition temperature is 850 ℃.