关键词： Mg alloy   plating   electroless   MMT   SEM   EIS  

摘要： Ni-B and Montmorillonite (MMT)-containing Ni-B deposits were electrolessly plated on AM60B magnesium alloy. The Ni-B coating showed cauliflower-like micromorphology, microcrystalline-amorphous microstructure, and thickness of about 15 mu m, which was not influenced by the inclusion of MMT nanoparticles. The surface roughness of the Ni-B coating changed from about 376 to 328 nm after the inclusion of MMT. The boron content of the electroless deposit was mildly increased after MMT inclusion. Thermal shock and porosity examinations revealed suitable adhesion and pore-free structure of the coatings, respectively. Polarization resistance of the Ni-B deposit in 3.5 wt-% sodium chloride was increased about 1.5 times by MMT inclusion. The corrosion current of the substrate was remarkably diminished from 46.89 to 0.12 mu A cm(-2) by the Ni-B plating. Also, MMT incorporation causes to further decrement of the corrosion current to about 0.03 mu A cm(-2).

关键词： 镁合金   复合材料   轧制   热处理   力学性能  

摘要： 对前期制备出的原位AlN/AZ91镁基复合材料进行轧制及热处理工艺研究,利用X-ray衍射仪(XRD)、扫描电镜(SEM)、光学显微镜(OM)、能谱仪(EDS)等对不同轧制及热处理工艺条件下镁基复合材料轧制板材的微观组织进行表征,并对复合材料进行室温拉伸力学性能测试和分析。结果表明:通过优化轧制及热处理工艺,显著改善了原位AlN/AZ91复合材料的微观组织,成功制备出抗拉强度358MPa,屈服强度333MPa,延伸率5.4%的原位AlN/AZ91镁基复合材料轧制板材。

关键词： Mg-Al-Sc合金   轧制   显微组织   力学性能  

摘要： 利用气体保护法制备了Mg-3Al-1.5Sc合金,并进行了变形量20%的轧制。对板材进行了合金显微组织和拉伸性能分析,研究了轧制对合金组织与性能的影响。结果表明:添加Sc元素可以有效地形成Al_(3)Sc硬质相颗粒,与铸态组织相比,轧制可明显提高合金的屈服强度和抗拉强度,提高合金的塑性,并随着加载速率提高表现出应变率强化效应。

关键词： Mg−Nd−Zn−Zr alloy   drawing   annealing   mechanical properties   corrosion rate  

摘要： Mg−Nd−Zn−Zr magnesium alloy(JDBM)has been studied widely as biodegradable medical *** process high quality JDBM wires,effects of annealing on the mechanical properties and degradation behavior after drawing were studied by microscopic observations,tensile and immersion *** as-extruded wires with a diameter of 3 mm could be drawn up to 9 passes without annealing until 125%cumulative drawing *** recrystallization occurred after annealing at 325℃ for 30 min,350℃ for 5 min or 450℃for 3 min,*** temperature tensile tests and simulated body fluid immersion tests showed that annealing at slightly elevated temperature for short time could obtain better properties due to the finer grain size and more dispersive distribution of *** this study,annealing at 350℃ for 5 min is the best parameters which can be utilized to further fabricate fine wires.

关键词： 镁合金   焊接   焊丝间距   焊接参数  

摘要： 目的:探索镁合金DE-GMAW焊接过程影响因素。方法:使用AZ31B镁合金作为材料,分别进行不同旁路电流下焊接测试、不同脉冲参数下焊接测试,以及不同焊丝间距下的焊接测试。观察不同条件下镁合金材料焊接效果,分析DE-GMAW焊接过程影响因素。结果:旁路电流的变化会造成熔宽、余高的改变,旁路电流为160 A材料焊缝成型效果最佳;脉冲峰值电流的增加使得材料拉伸性能呈现先上升后下降趋势,电流为70A材料拉伸性能最佳;焊丝间距为3mm时,较高的电弧稳定性提升了焊接质量。结论:镁合金DE-GMAW焊接过程影响因素,主要包括旁路电流、脉冲参数与焊丝间距三种因素,都会影响最终的焊接质量。

关键词： 镁合金   稀土镁合金   固溶处理   力学性能  

摘要： 在AZ61镁合金中添加了少量富Ce混合稀土元素,重点研究了固溶工艺对新型AZ61-RE合金的微观组织和力学性能的影响规律。结果表明:AZ61-RE镁合金铸态组织主要由α-Mg基体、沿晶界网状分布Mg_(17)Al_(12)相、花瓣状的Al_(10)RE_(2)Mn相、块状的Al_(11)RE_(4)相组成。随固溶温度(350~450℃)升高及保温时间(3~12 h)延长,Mg_(17)Al_(12)相不同程度地溶解于基体中,但稀土相几乎不变;显微硬度呈逐渐减小的趋势,屈服强度和抗拉强度呈逐渐减小的趋势,但断裂伸长率变化不大,这应与固溶处理后残留的稀土相处易萌生微裂纹有关。拉伸试样断口形貌表明,铸态和固溶处理后材料断裂模式均表现为韧脆混合型断裂特征。

关键词： 喷射沉积   镁合金微细管   纳米晶结构   生物材料  

摘要： 镁合金作为新型可降解生物材料,在第四代血管支架植入产品领域具有重要的应用价值,但微细管材较大的加工难度制约了其应用推广。提出电爆喷射沉积镁合金微细管的新方法,并对其工艺过程进行了试验研究。结果表明,丝径0.5 mm、初始电压14 kV、沉积距离25 mm时获得的沉积层的均匀性、致密性以及整体性较好且具备纳米晶组织结构,并制备出外径3.5 mm、壁厚0.12 mm的镁合金微细管,符合镁合金血管支架的尺寸要求。

关键词： 建筑隔板   Mg-3Al-1Zn-0.8Ti合金   挤压成形   力学性能   耐腐蚀性能  

摘要： 对建筑隔板用镁合金试样进行了挤压成形,研究了添加和不添加Ti元素对建筑隔板用镁合金试样的影响,并进行了显微组织、力学性能和耐腐蚀性能的测试、对比和分析。结果表明:与未添加元素Ti的Mg-3Al-1Zn合金相比,Mg-3Al-1Zn-0.8Ti合金的晶粒细化,抗拉强度和屈服强度分别增大14、37 MPa,质量损失率减小了37.15%,力学性能和耐腐蚀性能得到提升。Ti元素的添加有益于建筑隔板用Mg-3Al-1Zn镁合金综合性能的提升。

关键词： layer-by-layer assembly   coating   magnesium alloys   corrosion resistance   biocompatibility   antibacterial ability  

摘要： Magnesium(Mg)and its alloys are considered as ideal biodegradable materials due to their excellent mechanical properties and *** order to improve the surface properties to allow better adaptation to the surrounding tissue of the body,surface modification has played a significant role in satisfying multiple clinical requirements such as corrosion resistance,biocompatibility,and antibacterial ***,layer-by-layer(LbL)self-assembly,which can be applied for biodegradable Mg alloys due to its extensive choice of usable units,holds great promise among all the surface *** this review,the mechanisms of the driving force(i.e.,electrostatic interaction,hydrogen bonding,charge transfer interaction and covalent bonding),cuttingedge advances in preparation methods(e.g.,dipping,spraying,and spinning)and the functional properties(corrosion resistance,antibacterial activity,and biocompatibility)that could be achieved by the LbL coatings are summarized.A reasonable trend of the potential development of LbL for bioMg alloys is also proposed at the end of this article.

关键词： 镁合金   选区激光熔化   增材制造   微观组织   力学性能  

摘要： 采用选区激光熔化技术制备了AZ91D镁合金,利用光学显微镜、扫描电镜和显微硬度计等研究了选区激光熔化AZ91D镁合金的组织与性能,并与传统铸造工艺进行了对比。结果表明,选区激光熔化制备的镁合金比常规铸造工艺所获得的晶粒更细小,显微硬度更高。同时,选区激光熔化工艺可以大幅提升AZ91D镁合金的抗拉强度与伸长率,性能指标远超传统铸件。