磁控溅射铝膜的退火对膜组织结构转变的影响

利用ＳＥＭ、ＴＥＭ以及ｘ射线衍射，研究了磁控溅射Ａｌ膜的退火对膜组织 结构转变的影响。Ａｌ膜被磁控溅射在Ｎｉ基体上，所得镀膜分别经 １００℃、２００℃、 ３００℃、４００℃、５００℃、５５０℃和 ６００℃真空退火。结果表明， １００℃开始 Ａｌ膜再结晶； ４００℃开始有Ａｌ－Ｎｉ金属间化合物相生成，随温度升高，金属间化合物相的形成顺序为 Ａｌ３Ｎｉ—Ａｌ３Ｎｉ２－Ｎｉ３Ａｌ ＡｌＮｉ。薄膜的组织也由开始的细颗粒状组织转变为多边形 晶粒组织。     

高能球磨制备纳米晶Al—Cu合金

利用高能球磨工艺制备了纳米晶Ａｌ－Ｃｕ合金，发现按Ａｌ５０Ｃｕ５０配比纯元素粉同能球地，形成了纳米晶的Ｃｕ９Ａｌ４金属间化合物，初步探讨了高能纳米晶金属间化合物的形成过程。     

高能球磨制备纳米晶Al－Cu合金

利用高能球磨工艺制备了纳米晶Ａｌ－Ｃｕ合金。发现按Ａｌ_（５０）Ｃｕ_（５０）配比纯元素粉末高能球磨时，形成了纳米晶的Ｃｕ_９Ａｌ_４金属间化合物。初步探讨了高能球磨纳米晶金属间化合物的形成过程。     

TiAl金属间化合物的高温氧化与防护研究进展

ＴｉＡｌ金属间化合物在高温下形成Ａｌ２Ｏ３／ＴｉＯ２混合氧化膜，抗氧化能力较差，耐施加合适的防护涂层。本文综合评述ＴｉＡｌ金属间化合物的高温氧化机理，合金元素、表面处理及防护涂层对其抗氧化性能的影响。     

Ni3Al金属间化合物及溅射CoCrAlY涂层的高温热腐蚀

研究了Ｎｉ３Ａｌ金属间化合物及溅射ＣｏＣｒＡｌＹ涂层在９００～９５０℃空气中，表面存在（Ｎａ，Ｋ）２ＳＯ４盐膜时的热腐蚀行为，结果表明，Ｎｉ３Ａｌ遭受严重的热腐蚀，溅射ＣｏＣｒＡｌＹ涂层可以通过在表面迅速形成保护性Ａｌ，Ｃｒ氧化膜而显著改善Ｎｉ３Ａｌ的耐热腐蚀性能。     

Ti3Al金属间化合物的熔盐热腐蚀

采用电化学方法并结合扫描电镜、Ｘ射线衍射、电子探针和能谱等物相分析技术研究了Ｔｉ３Ａｌ金属间化合物在８００℃熔融ＮａＣｌ－（Ｎａ，Ｋ）２ＳＯ４体系中的腐蚀行为。结果表明，Ｔｉ３Ａｌ合金耐熔盐蚀性能远低于Ｎｉ基ＩＮ７３８合金。腐蚀时在合金表面形成外层为ＴｉＯ２，内层为富Ｎｂ的Ｎｂ２Ｏ５，Ａｌ２Ｏ３，ＴｉＯ２的混面腐蚀产物层迅速增厚。腐蚀产物内层的富Ｎｂ氧化物破坏了膜层与合金基体的粘附性。     

颗粒增强Ti－Al化合物基复合材料

本文在介绍Ｔｉ－Ａｌ金属间化合物基体及其颗粒增强剂的基础上，重点讨论了利用ＸＤ合成法、自蔓延高温合成法及真空热压法制造ＴｉＢ２、ＳｉＣ、Ａｌ２Ｏ３、ＴｉＮｂ等颗粒增强Ｔｉ－Ａｌ金属间化合物基复合材料的力学性能，同时还对颗粒增强Ｔｉ－Ａｌ金属间化合物基复合材料的其它制造方法，如反应热压烧结法、冲击波固结法、高能高速法的工艺、特点也进行了简要叙述。     

真空电弧镀DZ22合金NiCrAlY涂层性能研究

真空电弧镀ＤＺ２２合金ＮｉＣｒＡｌＹ涂层性能研究北京航空材料研究所吴凤筠一、前言真空电弧镀膜设备Ａ１０００采用电弧放电直接蒸发镀膜材料制成的阴极靶，与同类型镀膜设备一样有如下特点：ａ．金属阴极蒸发源不熔化；ｂ．由磁场控制电弧放电，可细化膜层微粒；ｃ．...     

镍基合金上离子束辅助沉积双轴取向的YSZ膜—YBCO超导膜缓冲层

用双离子束辅助沉积（ＩｏｎＢｅａｍＡｓｉｓｔｅｄＤｅｐｏｓｉｔｉｏｎ，ＩＢＡＤ）方法在Ｎｉ－Ｃｒ合金上合成了具有（００ｌ）择优取向，平面双轴排列的ＹＳＺ膜（Ｙ２Ｏ３－ＺｒＯ２）作为ＹＢＣＯ超导膜缓冲层。辅助轰击离子束方向与衬底法线的夹角５４０左右时可获得最佳的（００ｌ）择优效果。８０００Ｃ高温退火后其结构有较大的改善。在其上用ＭＯＣＶＤ方法生长的ＹＢＣＯ膜的Ｔｃ＝８８Ｋ，Ｊｃ＝１０×１０４Ａ／ｃｍ２（０Ｔ，７７Ｋ），并且从Φ扫描的结果说明了ＹＳＺ缓冲层上ＹＢＣＯ膜的生长机制。     

TiAl和Mo5Si3金属间化合物基高温结构材料及其合金化研究

对比分析了ＴｉＡｌ和Ｍｏ５Ｓｉ３金属间化合物的性能特点,应用前景和存在问题,并对这两种金属间化合物的合金化研究作了综述和展望。近来研究微量镁和镍在ＴｉＡｌ合金中的作用发现,微合金化可提高变形合金的热加工工艺性能和促进铸造合金组织的细化,是ＴｉＡｌ金属间化合物进一步合金化研究的重要方向。根据模量计算和常用合金元素在Ｍｏ５Ｓｉ３相中溶解度的测定,结果,讨论了以合金化韧化Ｍｏ５Ｓｉ３化合物的潜力。     

Grid emission suppression characteristics of molybdenum grids coated with Hf and Pt films

Hf and Pt were deposited onto molybdenum grids by ion beam-assisted deposition (IBAD). Electron emission characteristics from these coated molybdenum grids contaminated by active electron emission substances (Ba, BaO) of the cathode were measured using the analogous diode method. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were performed on the surface of molybdenum grids coated with Hf and Pt films. When emission substances were deposited onto the grid surface, the reaction between BaO and Hf formed a BaHfO₃ compound that markedly reduced the accumulation of BaO and accordingly decreased grid emission. The decomposition of BaO on the surface of Pt under high temperature was believed to lead to the formation of Ba and its re-evaporation from the surface, reducing active electron emission substances with a consequent significant reduction in grid emission. According to the comparison of their grid emission suppression mechanisms, it could be concluded that grid emission suppression was mainly the reduction of active electron emission substances on the grid surface, in particular BaO. This could be a worthwhile approach for the development of new grid coating materials.     

离子束辅助沉积铪膜抑制栅电子发射性能研究

利用离子束辅助沉积（IBAD）方法在Mo栅极表面沉积铪膜,采用模拟二极管方法测量和比较阴极活性物质Ba、BaO蒸发在镀铪和纯钼栅极表面的电子发射性能。实验结果表明,镀铪栅极抑制电子发射性能较好,并初步探讨了离子束辅助沉积铪膜抑制栅电子发射的机理。     

Effect of Applied Pressure on the Joining of Combustion Synthesized Ni3Al Intermetallics with Al Alloy

We focused on the surface reinforcement of ligth weight casting alloys with Ni-AI intermetallic compounds by in-situ combustion reaction to improve the surface properties of non-ferrous casting components.In our previous works,green compact of elemental Ni and Al powders were reacted to form Ni-3Al intermetallic compound by SHS （Self-propagating high temperature synthesis） reaction with the heat of molten Al alloy and simultaneously bonded with Al casting alloy.But some defects such as tiny cracks and porosities were remained in the reacted compact.So we applied pressure to prevent thermal cracks and fill up the pores with liquid Al alloy by squeeze casting process.The compressed Al alloy bonded with the Ni-3Al intermetallic compound was sectioned and observed by optical microscopy and scanning electron microscopy （SEM）.The stoichiometric compositions of the intermetallics formed around the bonded interface and in the reacted compact were identified by energy dispersive spectroscopy （EDS） and electron probe micro analysis （EPMA）. Si rich layer was formed on the Al alloy side near the bonded interface by the sequential solidification of Al alloy.The porosities observed in the reacted Ni-3Al compact were filled up with the liquid AI alloy.The Si particles from the molten Al alloy were detected in the pores of reacted Ni-3Al intermetallic compact.The Al casting alloy and Ni-3Al intermetallic compound were joined very soundly by applying pressure to the liquid Al alloy.     

The structure and phase change of a molybdenum grid coated with silicon and carbon composite thin films annealed at high temperature

Si-C composite thin films were deposited onto molybdenum substrates by radio-frequency magnetron sputtering. In order to simulate the working conditions of a grid contaminated by the active electron emission substance BaO from the hot cathode of a pulse-controlled grid travelling-wave tubes (TWTs), BaO layers were chemically deposited on the surface of the Si-C films. The structure and phase changes of BaO/Si-C/Mo systems were investigated using Raman scattering and XRD analysis after annealing at temperatures from 973 to 1273 K. The results show that high temperature annealing leaves only the high work function materials, SiC (about 4.4 eV) and SiO₂ (about 3.1 eV), remaining on the surface. The results are discussed in terms of chemical reactions believed to occur during annealing and the importance of these for electron suppression from grids in working TWT devices.     

加热温度与保温时间对铝-硅镀层组织演变的影响

采用扫描电镜观察了钢板表面铝-硅镀层的微观组织,利用热模拟机研究了铝-硅镀层在不同加热温度和保温时间下镀层中合金层厚度的变化规律,利用辉光光谱仪测定了铁元素向合金层中的扩散规律。结果表明:热处理前镀层合金层组织由Fe₂Al₅二元金属间化合物和Fe₂SiAl₇三元金属间化合物组成,热处理后镀层合金层组织由Fe₂SiAl₂,Fe₂Si₂Al₅等金属间化合物组成,镀层表面生成致密的Al₂O₃膜;硅元素在合金层与镀层的交界处富集,抑制了铁元素由钢基体向镀层表面的扩散,可以有效阻止合金层厚度的进一步增加;随着加热温度升高、保温时间延长,铁元素溶出量增多,镀层表面铁质量分数达到45%~55%,导致合金层的厚度逐渐增大。     

硬质相对冷喷涂FeAl金属间化合物涂层性能的影响

FeAl金属间化合物具有优良的物理性能和力学性能,但其室温塑性和断裂韧性低,限制了其工程应用.利用机械合金化制备了Fe(Al)固溶体合金粉末及Al2O3,WC硬质相增强的复合合金粉末,通过冷喷涂沉积涂层并结合后热处理原位反应制备了FeAl金属间化合物涂层及其复合涂层.利用扫描电镜(SEM)、X射线衍射仪(XRD)及显微硬度仪等研究了硬质相对球磨粉末组织结构、冷喷涂FeAl金属间化合物涂层组织结构及性能的影响.结果表明.硬质相可显著加速球磨粉末内部层状结构的细化程度,喷涂态涂层具有不同于传统热喷涂涂层的层状组织结构,热处理可实现喷涂态涂层中Fe(Al)固溶体向FeAl金属间化合物的原位转变,致使层状结构消失,获得无粒子界面的FeAl金属间化合物涂层,弥散分布的硬质相可显著提高冷喷涂FeAl金属间化合物涂层的强化稳定性.     

MB2-LY12扩散焊接头界面组织结构及其形成机制

采用真空扩散焊接技术进行镁合金（MB2）与铝合金（LY12）的焊接,采用超声波无损检测,电子探针、X射线衍射和扫描电镜等手段研究了焊接温度对焊接接头界面附近组织结构的影响,分析了界面反应物的生成机理。结果表明,随着焊接温度的升高,焊接界面的焊合率提高,在焊接压力为3 MPa、保温时间为100 min的条件下,温度升高到480℃完全焊合,在Al侧和Mg侧分别形成了A1（ss,Mg）和Mg（ss,A1）固溶体,焊接界面形成了Al₁₂Mg₁₇、AlMg、Al₃Mg₂三种金属间化合物层,其厚度随着焊接温度的升高而增加,其中AlMg层厚度增长得最快,接头断裂发生在金属间化合物层且呈阶梯状断裂。界面扩散区的形成主要由有效物理接触阶段、固溶体形成阶段、金属间化合物相形成阶段以及金属间化合物增长阶段组成。     

Gap-filling of Cu–Al alloy into nanotrenches by cyclic metalorganic chemical vapor deposition

In this work, Cu–Al alloy thin films with lower values of electrical resistivity than that of an Al-free Cu thin film were produced by cyclic metalorganic chemical vapor deposition (MOCVD), followed by thermal annealing of the Cu/Al multilayer formed, with controlled Cu and Al precursor delivery times. The Ru-coated SiO₂ trench with the opening width of 50 nm and aspect ratio of 1:6.7 could be completely filled by the Cu–Al alloy. The Ru/SiO₂ trench, filled conformally and voidlessly by the Cu–Al (0.7 at.%) alloy, showed no presence of intermetallic compounds.     

Effect of Vacuum Heat Treatment on the Microstructure and Tribological Property of Ti–6Al–4V Alloy with Cu Coating

The effect of vacuum heat treatment on the interface microstructure and tribological property of Cu-coated Ti – 6Al – 4V alloy is investigated herein. After the vacuum heat treatment process, a diffusion layer is formed at the interface between the Cu coating and the Ti – 6Al – 4V substrate. The formed intermetallic compounds at the interface between the Ti – 6Al – 4V substrate and Cu coating are CuTi₂, CuTi, Cu₄Ti₃, and β-Cu₄Ti. The activation energy of intermetallic compound growth in the diffusion zone of Cu-coated Ti – 6Al – 4V is 126.0 kJ mol⁻¹, and the pre-exponential factor is 0.1 m² s⁻¹. The tribological properties of the Cu-coated Ti – 6Al – 4V alloy are best when subjected to diffusion treatment at 700 °C for 300 min, with weight loss reduced by 58.2% compared to the Ti – 6Al – 4V alloy. The wear resistance of the Ti – 6Al – 4V alloy can be enhanced by Cu coating and vacuum diffusion heat treatment, and the formation of the Cu – Ti intermetallic compound contributes to this improvement. These findings offer new insights for further advancements in the tribological properties of titanium alloys.     

Interfacial bonding mechanism in Al/coated steel dissimilar refill friction stir spot welds

Defect-free dissimilar Al/zinc coated steel and Al/AlSi coated steel welds were successfully fabricated by refill friction stir spot welding. However, Al alloy and uncoated steel could not be welded under the same welding condition. Al-Zn eutectic layer formed at the Al/zinc coated steel interface showed non-uniformity in thickness and nanoscale intermetallic (IMC) produced was discontinuous. The bonding formation between the Al-Zn layer and the surrounding materials was attributed to a liquid/solid reaction mechanism. Bonding formation at Al alloy and AlSi coated steel interface was attributed to a solid/solid reaction mechanism, as the joining process did not involve with melting of base metals or AlSi coating materials. Kissing bond formed at the weld boundary acted as a crack initiation and propagation site, and the present study showed that weld strength of Al 5754/AlSi coated steel was greatly influenced by properties of original IMC layer.