稀土钇对AlZnMgCu合金组织及性能的影响

利用金相显微镜、图象分析仪、ＳＥＭ、Ｘ射线衍射仪等实验手段,研究了单一稀土钇（Ｙ）对航空用铝合金ＡｌＺｎＭｇＣｕ铸态组织和力学性能的影响规律．实验结果表明,少量稀土钇能细化合金的二次枝晶组织,减小共晶化合物尺寸．钇的加入主要和铜（Ｃｕ）、硅（Ｓｉ）等元素结合生成相应的稀土化合物相．研究发现,合金中加入少量钇稀土能有效改善合金的冲击韧性     

高温下Al2O3／Al合金复合材料的界面稳定性和拉伸强度

利用挤压铸造制备了Ａｌ２Ｏ３／Ａｌ合金复合材料，研究了高温下复合材料的界面稳定性和拉伸强度，结果表明，在Ａｌ２Ｏ３／ＺＬ１０９复合材料中，纤维与基体之间的界面上发生了化学反应，有利于纤维与基体的结合；在高温下界面层结构稳定，与基体合金相比。Ａｌ２Ｏ３／ＺＬ１０９复合材料具有较好的高温拉伸强度，工作温度可提高１００℃以上，另外，分析了Ａｌ２Ｏ３／ＺＬ１０９复合材料高温拉抻的失效形式。     

稀土对纤维相Cu-12%Ag合金组织性能的影响

为研究稀土微合金化在纳米纤维强化Cu-Ag合金中的作用，制备了纤维相增强Cu-12%Ag和Cu-12%Ag-0.3%RE合金．采用冷拉拔结合中间热处理方法制备该类合金，观察并测定了不同变形程度下稀土元素对合金显微组织、力学性能和电学性能.实验结果表明，随变形程度增大，合金硬度和强度上升，相对电导率下降.稀土元素可增加原始组织枝晶轴间距、共晶体数量及共晶体中Ag的质量分数，提高合金的硬度，但对合金抗拉强度没有明显影响.在较低的变形程度范围内，稀土元素使合金导电性能略有降低.在大变形范围内，稀土元素可在一定程度上改善导电性能.     

TZS88合金的时效处理

研究了自然时效和人工时效状态下新型铝基合金TZS88的性能,且通过金相显微镜、扫描电镜对其时效组织进行了分析。结果表明,TZS88合金人工时效与自然时效后的组织都由α（Al）固溶体基体＋Sn相＋化合物构成。与自然时效相比,TZS88合金人工时效后的抗拉强度增加约5％,硬度增加0．5～5．3HBS,而伸长率下降达25％左右。     

铝合金化学镀镍磷合金结构和性能

针对质子交换膜燃料电池双极板的需要，以铝合金为基体材料，采用碱性和酸性双溶液体系化学镀镍磷合金．采用电子探针方法测定了镀层中镍磷含量，X衍射方法研究了热处理对镀层结构的影响，伏安法研究了热处理对镀层耐蚀性的影响．试验结果表明，热处理明显影响镀层的结构和耐蚀性，对于P含量为12．1％（质量）的镍磷合金镀层，经过200—250℃热处理后，晶化不明显但耐蚀等性能明显改善，可以用作质子交换膜燃料电池双极板．     

锻造对AlFeVSi合金组织和性能的影响

ＡｌＦｅＶＳｉ合金具有耐高温,耐腐蚀等优异性能。作者研究了该合金的锻造工艺,旨在为将来生产大件做基础性准备工作。采用喷射沉积－包套锻造工艺制备样品,通过金相,力学性能,ＳＥＭ,ＴＥＭ等实验,对锻前,锻后的合金组织和性能进行对比分析。     

时效处理对7050铝合金组织与性能的影响

对7050铝合金进行硬度测试、腐蚀性能测试和透射电子显微分析(TEM),研究了单级时效处理对合金组织与性能的影响。实验结果表明:7050铝合金具有较强的时效硬化效应。单级时效温度由120℃升高到160℃时,合金时效硬化速度显著加快,合金进入峰时效状态所需时间显著缩短,但合金的峰值点的硬度降低。时效处理后合金晶内析出了大量的尺寸细小的η'相,弥散分布在基体中。合金晶界处析出了粗大的平衡相,成分为MgZn_2,PFZ出现。随着时效温度的升高,合金晶间析出相连续且粗大,PFZ宽化,合金的抗晶间腐蚀性能持续下降。对于剥落腐蚀来说,合金的腐蚀程度不仅与晶界结构有关,还与晶界数量有关,温度上升,合金晶粒尺寸迅速增大,晶界数目显著减少,二者相互作用最终导致了合金的抗剥落腐蚀性能的提高。     

铝合金化学镀镍磷合金结构和性能

针对质子交换膜燃料电池双极板的需要,以铝合金为基体材料,采用碱性和酸性双溶液体系化学镀镍磷合金.采用电子探针方法测定了镀层中镍磷含量,X衍射方法研究了热处理对镀层结构的影响,伏安法研究了热处理对镀层耐蚀性的影响.试验结果表明,热处理明显影响镀层的结构和耐蚀性,对于P含量为12.1%（质量）的镍磷合金镀层,经过200～250℃热处理后,晶化不明显但耐蚀等性能明显改善,可以用作质子交换膜燃料电池双极板.     

Thermoelectric properties of quaternary Mg_2Sn_(0.4)Si_(0.6-x)Ge_x alloys

Quaternary alloys Mg2Sn0.4Si0.6-xGex(x=0,0.02,0.05,0.08 0.1,and 0.2) were prepared using induction melting followed by hot-pressing.Relative densities of the sintered samples were over 97% of the theoretical values.Multiple phases were detected in the samples.It was found that the Seebeck coefficient was sensitive to the content of Mg2Ge and a maximum value of about 350 μV·K-1 was obtained.The introduction of Ge increases the electrical conductivity and the thermal conductivity simultaneously.The mechanism ...     

Microstructure and Hydrogen Absorption/Desorption Behavior of Mg_(23-x)La_xNi_(10) Alloy

Induction melting was used as a routine method to synthesize Mg_(23)Ni_(10), Mg_(22)LaNi_(10) and Mg_(21)La_2Ni_(10) alloys, and followed by a detailed microstructural characterization which included X-ray diffraction(XRD), scanning electron microscopy(SEM) with energy dispersive spectrometer(EDS), high resolution transmission electron microscope(HRTEM) and hydrogen absorption/desorption measurements. XRD analysis results showed that Mg_2Ni and Mg phases were detected in the XRD pattern of the Mg_(23)Ni_(10) alloy, however, the La addition results in conversion from Mg to LaMg_3 and La_2Mg_(17) phases and appearance of crystal defects included dislocations, twin grain boundary and vacancy in the Mg_(22)LaNi_(10) and Mg_(21)La_2Ni_(10) alloy textures. The total maximum hydrogen absorption capacity was 4.45 wt% for the Mg_(23)Ni_(10) alloy, however, the Mg_(22)LaNi_(10) and Mg_(21)La_2Ni_(10) alloys with vacancy, dislocations and twin grain boundary, absorbed 3.66 wt% and 3.60 wt%, respectively, indicating that the La addition led to decreasing of the maximum hydrogen absorption capacity. Besides, hydrogen absorption/desorption of 90% of saturated state expended for about 456 and 990 s for pristine Mg_(23)Ni_(10) alloy, by contrast, the time decreased owing to improvement of hydrogen absorption and desorption kinetics in the alloy with La element, with which the uptake time for hydrogen content to 90% of saturated state was 150 and 78 s, and 90% hydrogen can be released in 930 and 804 s for Mg_(22)LaNi_(10) and Mg_(21)La_2Ni_(10) alloys in the experimental condition.     

La_(1.8)Ca_(0.2)Mg_(14)Ni_3合金在甲苯溶液中球磨改性后的储氢性能

采用在甲苯介质中球磨以改善La1.8Ca0.2Mg14Ni3的储氢性能。随着球磨时间的增加,合金的吸放氢性能得到显著地提高,在20 h达到最高。其在513 K,4.0 MPa氢压下初次活化时,吸氢质量分数达到了3.95%,在3次活化后,300 K时的吸氢质量分数达到3.85%,在613 K,一个大气压的放氢质量分数在900 s内达到了4.92%。通过XRD和SEM分析,球磨后合金颗粒粒径明显减小且有非晶化趋势。在球磨过程中形成了电子络合体(electrondonor-acceptor,EDA)体系。合金颗粒粒径、非晶化程度和EDA共同作用使球磨20 h的合金表现出最优异的吸放氢性能。     

Calculation of interaction of AlCl,AlCl_2 and AlCl_3 on Al_4C_3(001) Al_4CO_4(001) and Al_2CO(001) planes

To make sure the intermediate products of the carbothermic reduction of Al2O3 process, such as Al4CO4, Al2CO and Al4C3,and the interaction of AlCl, AlCl2, AlCl3 with Al4CO4, Al2CO and Al4C3, respectively, thermodynamic analyses were used to study the chloride reaction production of them under the vacuum situation. The stable structures and electronic properties of AlCl, AlCl2 and AlCl3 adsorbed on Al4CO4, Al2CO and Al4C3 were calculated by first-principles calculations by the CASTEP module in the Materials Studio program. The results show that the AlCl3 and AlCl2 molecules have decomposed on the plane of Al4C3(001), while there are no obvious decomposition of AlCl3 and AlCl2 on Al4CO4(001) and Al2CO(001) planes. The adsorption of AlCl on the Al4CO4(001)and Al2CO(001) planes is stronger than that on the Al4C3(001) plane. The interaction strength of AlCl3, as well as AlCl2, with Al4CO4,Al2CO and Al4C3 is in the sequence of Al4CO4Al2COAl4C3, while the interaction strength of AlCl with Al4CO4, Al2CO and Al4C3 is in the sequence of Al4CO4Al2COAl4C3.     

Fabrication and Properties of Ag/Mg_(0.2)Zn_(0.8)O/La_(0.67)Ca_(0.33)MnO/p~+-Si Resistive Switching Heterostructure Devices

Mg_(0.2)Zn_(0.8)O(MZO)/La_(0.67)Ca_(0.33)MnO(LCMO) heterostructure was deposited on p~+-Si substrates by sol-gel spin coating technique. The Ag/MZO/LCMO/p~+-Si devices exhibit a bipolar, reversible, and remarkable current-voltage characteristic at room temperature. An obvious multilevel resistive switching effect is observed in the devices. The dominant conduction mechanism of the devices is trap-controlled space charge limited current. The resistance ratio of high resistance state and low resistance state of the devices is about six orders of magnitude, and the degradation is invisible in the devices after 250 successive switching cycles. The present results suggest that the Ag/MZO/LCMO/p~+-Si devices may be a potential and multilevel candidate for nonvolatile memory application.     

Li_3(Mg_(0.95)Co_(0.05))_2SbO_6陶瓷微波介电性能研究

采用传统固相反应法制备Li_3(Mg_(0.95)Co_(0.05))_2SbO_6微波介质陶瓷。研究部分Co~(2+)离子取代Mg~(2+)离子对Li_3(Mg_(0.95)Co_(0.05))2SbO_6陶瓷烧结特性、物相组成、显微组织和微波介电性能的影响。采用XRD、SEM及矢量网络分析仪对材料晶体结构、显微组织和微波介电性能进行表征。XRD结果表明样品主相为岩盐结构Li_3(Mg_(0.95)Co_(0.05))_2SbO_6相。实验结果表明,随着烧结温度升高,样品密度和εr值逐渐增加,Q×f值先增大后减小,τf值在-11.3~-8.1ppm/℃范围内波动。部分Co~(2+)离子取代Mg~(2+)离子能有效改善Li_3Mg_2SbO_6基陶瓷烧结特性和微波介电性能。1 175℃、5h烧结Li_3(Mg_(0.95)Co_(0.05))_2SbO_6陶瓷具有最佳微波介电性能,且对应参数分别为ε_r=9.2、Q×f=49 804GHz、τ_f=-11.3ppm/℃。     

激光熔覆钴基稀土合金的研究

本文给出了两种新的激光熔覆钴基稀土合金材料的研究结果。试验表明：加入适当的稀土添加剂可以细化合金组织，进一步提高其硬度、耐磨性、耐蚀性和抗氧化性能；经中温加,塑性明显得到改善，同时硬度也有所提高，故可作为不锈钢阀座等易磨损件的表面材料。     

Preparation, Characterization and Dielectric Properties of Ba_6Mg_(0.67)Nb_(9.33)O_(30) Ceramic

1IntroductionSince the discovery of ferroelectricity andrelated prop-ertiesin BaTiO3,alarge amount of research workonoxides,insearch of novel materials for industrial applications,hasbeen done.High performance dielectric ceramics is appliedas key material…     

铝合金焊接角变形测量装置的确立

设计和制作了低刚性夹式位移传感器，以实现对测点的动态测量．采用非电量测量的方式，测量铝合金的焊接角变形，克服了焊接电弧的干扰问题，保证了测量结果的准确性     

快速凝固(2024Al)-20Si-5Fe合金的磨损行为

采用双级雾化水冷快凝与粉末冶金技术制备了（２０２４Ａｌ）－２０Ｓｉ－５Ｆｅ耐磨合金,分析了 合金的微观组织,利用磨损实验研究了合金的耐磨性和磨损失效形式．结果表明：快凝粉末冶金 合金具有比铸造合金更细小的微观组织,更高的耐磨性和减磨性;磨损失效形式主要是磨粒磨 损和疲劳磨损,而铸造合金的磨损失效形式主要是磨粒磨损、粘着磨损和部分氧化磨损．