关键词： 铸造镁合金   镁合金   裂纹   应力应变测试   缩松  

摘要： 某型航空机载光电设备试制过程中,在冲击摸底试验后,设备中镁合金材料的主承重件连接盘出现裂纹。通过宏观分析、化学成分分析、金相检验及应力应变测试等方法,对连接盘产生裂纹的原因进行了分析。结果表明:由于连接盘采用手工铸造工艺,不可控因素较多,导致在个别连接盘加强筋内部产生大量缩松缺陷,影响了铸件的连续性,使得零件的承载能力及抗疲劳能力降低,试验时受到力的作用后在内部缺陷处萌生裂纹源,裂纹扩展,最终导致连接盘加强筋过载开裂。

关键词： 模糊PID   新型铸造镁合金   力学性能   磨损性能  

摘要： 对Mg-8Al-0.6Zn-0.4V和Mg-8Al-0.6Zn-0.5Zr两种镁合金进行了常规铸造和模糊PID控制铸造下的力学性能和磨损性能的测试与分析。结果表明:与常规铸造相比,模糊PID控制时Mg-8Al-0.6Zn-0.4V合金的抗拉强度、屈服强度分别增大22、23 MPa,断后伸长率仅减小0.3%,磨损体积减小27.59%;Mg-8Al-0.6Zn-0.5Zr合金的抗拉强度、屈服强度分别增大24、23 MPa,断后伸长率减小0.4%,磨损体积减小28.13%。模糊PID控制有助于提高两种铸造镁合金的力学性能和耐磨损性能。

关键词： ZK61M magnesium alloy sheet   Hot tensile deformation   Microstructure   Constitutive model  

摘要： Hot deformation behavior of the annealed ZK61 M magnesium alloy sheet was explored using tensile tests with strain rates varying from 0.001 to 0.030 s^(-1) in temperatures range of 423-513 *** obtained results indicate that the flow stress increased with deformation temperature decreasing and strain rate *** recrystallization(DRX)occurs when the temperature is higher than 423 K,and the recrystallization volume fraction increases with temperature *** a given temperature,the measured DRX volume fraction at a higher strain rate is smaller than that at a lower strain *** are observed throughout the tested temperature ***,they grow larger as temperature *** average absolute relative error(AARE)of 2.65%proves that the peak stress predicted by the constitutive model is in good agreement with the experimental *** correlation coefficient(R’)obtained for the predicted stress and the experimental value considering the strain on the material constant are between 0.9831 and *** addition,AARE and root mean square error(RMSE)are less than 6.5%and 8.5 MPa,*** indicates that the deviation of the predicted value from the experimental value is small and the predictions of the proposed model are reliable.

关键词： ZM1 alloy   Carbon nanotubes(CNTs)   Composites   Microstructure   Mechanical properties  

摘要： Melt processing is a promising process to fabricate Mg-CNTs(carbon nanotubes)composites with high performance and large *** this work,the liquidmixing technique and ball-milling processes as well as the stirring casting method were used to prepare ZM1-1.0 CNTs-L and ZM1-1.0 CNTs-B composites,*** composites were studied using optical microscopy(OM),Raman spectroscopy,scanning electron microscope(SEM),transmission electron microscope(TEM)and room-temperature tensile *** results show that the yield strength(YS),ultimate tensile strength(UTS),elongation and microhardness values of the ***-L composite are improved by 37.3%,29.6%,37.0%and33.3%,respectively,compared with those of ZM1 *** uniform dispersion of CNTs as well as the strong interfacial bonds with the Mg matrix is the main reason for the significant improvement in mechanical properties of the as-cast *** mixing combined with the stirring casting method is favorable to fabricate Mg-CNTs composite with high mechanical properties.

关键词： 水凝胶   抗菌活性   生物相容性   生物医学   抑菌活性  

摘要： 细菌感染是阻碍伤口愈合的重要因素之一,同时也是生物医学领域面临的一个重要问题。目前的抗菌水凝胶有着高抗菌活性、生物相容性以及可注射性等性能,并且其物理化学性质与生物组织相似,使得越来越多新型的抗菌水凝胶材料被用于治疗细菌感染。综述了近几年抗菌水凝胶的研究进展,归纳总结了几种不同类型的抗菌水凝胶的制备方法,抗菌活性和生物相容性等。重点阐述了抗菌水凝胶在伤口敷料、药物负载和传递以及组织工程等生物医学领域中的应用前景。

关键词： Mg−Gd−Y−Zn−Ag alloy   cooling process   long-period stacking ordered(LPSO)phase   surface film   micro-galvanic corrosion  

摘要： The corrosion behaviour of Mg−6Gd−3Y−1Zn−0.3Ag(wt.%)alloy components with different sizes after cooling was *** alloys in the small components(SC)cooled fast,which were composed ofα-Mg matrix and coarse long-period stacking ordered(LPSO)*** alloys in the large components(LC)cooled slowly,and there were thin lamellar LPSO phases precipitating inside the grains,except forα-Mg matrix and coarse LPSO *** hydrogen evolution test revealed that the corrosion rate of LC sample was higher than that of SC *** impedance spectroscopy(EIS)test showed that the surface film on LC alloys provided worse *** corrosion morphologies indicated that the precipitation of the thin lamellar LPSO phases in LC sample caused severe micro-galvanic corrosion,which accelerated the rupture of the surface film.

标准号: DIN EN ISO 11979-5-2021

关键词： 轻量化   高强钢   铝合金   镁合金   碳纤维复合材料  

摘要： 轻量化技术在汽车制造中被广泛应用,轻量化材料及相关新技术的大量使用是汽车减重的重要途径。参考大众、奥迪等车型用材情况,分析了高强度及超高强度钢、铝合金、镁合金等轻质合金、碳纤维复合材料等轻量化材料的种类、性能特点、制造工艺以及在汽车上的应用现状,从成本、效率及工艺等多个方面进行对比,并阐述了汽车轻量化未来发展趋势。旨在通过对轻量化材料及工艺的研究,为汽车选材提供参考依据。

关键词： 深冷处理   AZ91镁合金   β-Mg_(17)Al_(12)相   力学性能   耐磨性  

摘要： 对AZ91镁合金进行了固溶+不同深冷处理时间+时效的复合工艺处理,采用光学显微镜、X射线衍射仪、硬度仪、万能试验机以及摩擦磨损试验机等仪器设备研究了不同深冷处理时间对A291镁合金显微组织、力学性能及耐磨性能的影响规律。结果表明:AZ91镁合金经410℃8 h固溶+(-196)℃12 h深冷处理+180℃8 h时效复合工艺处理后,其硬度、抗拉强度及伸长率较未深冷处理的分别提高了19.2%、25%和37.4%,其平均摩擦因数与磨损率分别为0.22和0.382 mg/(m·N),较未深冷处理的降低了50%和32.7%。深冷处理工艺有效细化了AZ91镁合金组织的晶粒尺寸,促使β-Mg_(17) Al_(12)相成颗粒状且弥散均匀分布的析出,显著提高了其力学性能和耐磨性能。但随着深冷处理时间的增加,β-Mg_(17) Al_(12)相会逐渐偏聚与粗化,导致合金的力学性能有所下降。

关键词： 镁合金   微弧氧化   二硫化钼   固体润滑涂层  

摘要： 介绍了一种与镁合金微弧氧化层结合良好的二硫化钼固体润滑涂层制备工艺,采用二硫化钼、环氧树脂、添加剂及稀释剂混合体系经100℃固化而成,涂层厚度8~11μm,静摩擦系数小于0.2,动摩擦系数小于0.1,且摩擦实验后涂层未被磨穿,减磨涂层从微弧氧化层脱离的抗性达到0级。