ICP-AES测定镁合金中的Zn、Mn、Zr、Ce

采用 ICP- AES测定了镁合金中的 Zn、Mn、Zr、Ce,进行了酸度试验 ,氢氟酸用量试验 ,分析线的选择 ,并研究了基体元素对待测元素的干扰。测定值与标钢值吻合较好 ,RSD<5 %。方法简便可靠 ,可获得令人满意的分析结果。

Microstructure and mechanical properties of a high ductility Mg–Zn–Mn–Ce magnesium alloy

A high-ductility ZME200(Mg–2.3Zn–0.4Mn–0.2Ce^(1))alloy was newly developed for vehicle closure and structure applications,based on an earlier ZE20(Mg–2.0Zn–0.2Ce)alloy for extrusion applications.Previous study indicates that the hot deformation behavior of as-cast ZME200 alloy varies with processing parameters,namely temperature and strain rate.In this follow-up study,a conventional rolling process was optimized to obtain magnesium sheets with a very fine grain structure and high ductility.The microstructure,mechanical properties,and corrosion resistances of ZME200 alloy were investigated,and compared with those of commercial AZ31 magnesium alloy.It was demonstrated that the ZME200 alloy sheet exhibits extraordinarily higher ductility(36%in tensile elongation),much superior stretch formability(an Erichsen value of 9.5),lower anisotropy,comparable strength and corrosion resistance to AZ31 alloy.The unique RD–TD double split texture with remarkably reduced intensity and grain refinement gives rise to the significantly improved ductility and formability at room-temperature.

ICP-AES法同时测定硝酸锶晶体中十种掺杂元素

本文报道了用 ICP- AES法同时测定硝酸锶晶体中掺杂元素 Ag、Ca、Ce、Cu、Fe、L a、Mg、Mn、Na、Zn的分析方法。本方法采用基体匹配法与背景扣除法对基体干扰及光谱干扰进行校正。被测元素检出限为0 .1— 1 6 ng/ m L,合成样品的回收率为 90 %— 1 1 6 % ,相对标准偏差均小于 1 3%。本法简便、快速、准确。

挤压变形Mg-Mn-Zn-Ce合金的低周疲劳行为

针对稀土镁合金的疲劳行为进行研究,可为新型稀土变形镁合金的抗疲劳设计和合理利用提供可靠的理论依据.通过总应变幅控制的疲劳实验和断口形貌分析,确定了挤压变形Mg-Mn-Zn-Ce合金的循环变形行为和断裂机制.结果表明:对于挤压变形Mg-Mn-Zn-Ce合金而言,除在最低的外加总应变幅下呈现初期循环应变硬化,其后呈现循环稳定外,在其它外加总应变幅下均表现为循环应变硬化,且合金的弹性应变幅、塑性应变幅与断裂时的载荷反向循环周次之间的关系可分别用Basquin和Coffin-Manson公式描述.此外,疲劳裂纹的萌生和扩展均以穿晶方式进行.

Comparative studies on as-cast microstructures and mechanical properties between Mg-3Ce-1.2Mn-0.9Sc and Mg-3Ce-1.2Mn-1Zn magnesium alloys

The as-cast microstructures and mechanical properties of Mg-3Ce-1.2Mn-0.9Sc and Mg-3Ce-1.2Mn-1Zn magnesium alloys were investigated and compared. The results indicate that the Sc-containing alloy mainly consists of α-Mg, Mg12Ce and Mn2Sc phases, and the Zn-containing alloy is mainly composed of α-Mg and Mg12Ce phases. The morphologies of the Mg12Ce phases in the two as-cast alloys are different. The Mg12Ce phases in the Sc- and Zn-containing alloys mainly exhibit particle-like shapes and continuous and/or quasti-continuous nets, respectively. Furthermore, the grains of the Sc-containing alloy are finer than those of the Zn-containing alloy. In addition, the Sc- and Zn-containing alloys have similar as-cast tensile properties at room temperature and 300 °C. However, the Sc-containing alloy exhibits higher creep-resistant properties at 300 °C and 30 MPa for 100 h than the Zn-containing alloy.

微量Ce对热挤压态Mg-2Zn-0.4Ca-0.2Mn合金微观组织、力学性能及导热性的影响

通过近固相线温度挤压方法制备了一种具有高热导率、高伸长率的Mg-2Zn-0.4Ca-0.2Mn(wt%)合金,并探索了微量Ce元素对其微观组织及性能的影响。结果表明,热挤压态合金中晶粒呈双峰结构分布,其平均晶粒尺寸相比铸态晶粒显著下降。Ce的加入一方面使得合金内的第二相由Ca_(2)Mg_(6)Zn_(3)相转变为(Mg,Zn)_(11)Ce相,另一方面未再结晶区域占比从5.4%降低到了1.6%,平均晶粒尺寸从5.29μm下降到3.68μm,合金的基面织构强度明显弱化。由于晶粒细化和含Ce第二相的强化作用,合金的屈服强度从原来的163.67 MPa显著提升到237.44 MPa,伸长率从27.45%降低到19.58%,而Ce的添加虽然增加了组织中的第二相体积分数,但同时降低了Zn在基体中的固溶度,因此并未明显降低合金的热导率。

ZM71-xCe镁合金显微组织和力学性能

对添加小同含量ce元素的Mg—Zn—Mn系ZM71变形镁合金进行挤胜及热处理，测试不同状态下ZM71及ZM71-xCe合金的室温拉伸性能，利用光学金相显微镜（0M）、X射线衍射（XRD）、差热分析（DSC）、扫描电镜（SEM）以歧能谱（DES）、透射电镜（TEM）等分析试验手段观察了不同状态下的显微组织，初步探讨了ce元素存ZM71合金中的存在形式和作用机制及不同添加量对合金组织和力学性能的影响。结果表明：Ce元素上要以三元稀土相关在于合金中，主要分布在晶界和枝晶间，能够细化铸态组织；ce元素能够明显细化挤压态合会的组织，提升力学性能，但添加量应控制在1％以内，其中ZM71—0．5Ce具有最佳的综合力学性能，抗拉强度、屈服强度和延伸半分别为318MPa、250MPa和13．6％；时效热处理小能提升挤压态高锌含量的Mg—Zn—Mn—Ce合金力学性能。