高性能织构Cu基合金复合基带立方织构形成的研究

采用放电等离子体烧结的方法制备了外层为Cu_(60)Ni_(40)合金,芯层为Ni_9W合金的Cu基复合坯锭,结合传统的RABiTS路线成功获得了无铁磁性、高强度、强立方织构的Cu_(60)Ni_(40)-Ni_9W-Cu_(60)Ni_(40)复合基带。利用EBSD技术对复合基带轧制织构及再结晶退火后的微取向特征进行了分析表征。测试结果表明:大变形量冷轧后复合基带表面形成了典型的铜型轧制织构,在截面方向上织构呈现梯度分布的特征,在再结晶退火后该复合基带表面立方织构含量达到了97.6%(10°),并发现,在再结晶过程中立方织构优先在外层材料中形核、长大,并逐渐吞并周围的非立方晶粒。对其力学性能表征发现:该复合基带在室温下的屈服强度为170 MPa,达到了商业化Ni_5W合金基带的水平。     

退火工艺对镍基带中立方织构形成的影响

应用电子背散射衍射(EBSD)技术研究退火工艺(单步法和两步法)对形变量为99%的镍基带中立方织构形成的影响.结果表明,随着退火温度的升高,镍基带中立方取向和其它取向的晶粒平均尺寸不断增加,立方取向晶粒的平均尺寸比其它取向晶粒的平均尺寸要大,而且随着退火温度的升高,这种晶粒尺寸优势不断的增加;低温退火时退火工艺对立方织构含量影响不明显,而高温退火时其立方织构含量大幅增加;相对于单步退火法,两步退火法能有效的提高镍基带中立方织构的含量.     

复合基带外层Ni5W再结晶织构演变的研究

采用X射线四环衍射技术和背散射电子衍射技术,对具有多层结构的NiW合金复合基带外层Ni5W(at%)的形变织构和再结晶织构进行了研究。研究发现,梯度分布的形变织构和多层材料之间的扩散是决定复合基带外层Ni5W织构演变的两个主要因素。这为进一步研究金属合金复合材料各层之间的织构形成及其关联性奠定了基础。     

立方织构Ni/Cu双金属基带制备

对在铜带上沉积Ni层过程中,电化学参数对Ni层立方织构形成的影响进行了研究.研究结果显示:只有当阴极电位足够低、镀液pH值在3到4之间时,Ni层才具有立方织构.电化学参数对Ni层立方织构形成的影响可以用几何选择理论进行解释.最后,对Ni层立方织构的热稳定性也进行了研究.     

YBCO厚膜用立方织构Ni基带的X射线衍射研究

用冷轧和再结晶退火技术制备了ＹＢＣＯ超导厚膜用的立方织构Ｎｉ基带。并且对所制备的立方织构Ｎｉ基带进行了Ｘ射线衍射研究。提出并讨论了Ｎｉ基带立方织构质量评价实验中容量出现的问题。     

镍基铸造高温合金的热等静压处理

评述了镍基铸造高温合金的热等静压（HIP）处理对组织和力学性能的影响。镍基铸造高温合金由于存在着铸造工艺难以消除的气孔类缺陷，严重影响着合金的使用可靠性和成品率，通过HIP处理后的合金，不仅可有效地消除合金中的缺陷，获得致密合金，而且还可改善合金的显微组织，提高合金的拉伸、持久和疲劳性能，显著地减小性能分散度。     

无磁性强立方织构Cu_(60)Ni_(40)合金基带的制备和性能

采用轧制辅助双轴织构技术(RABi TS)制备了无磁性强立方织构的Cu60Ni40合金基带。对Cu60Ni40合金基带冷轧及再结晶退火后的织构进行分析。结果表明:轧制总变形量及再结晶退火工艺是影响Cu60Ni40合金基带再结晶晶粒取向的主要因素。经过大变形量冷轧,Cu60Ni40合金基带表面可以得到典型的铜型轧制织构。通过优化的冷轧及两步再结晶退火工艺获得了立方织构含量高达99.7%(≤10°)、小角度晶界含量高达95.1%的Cu60Ni40合金基带,Σ3孪晶界含量为0.1%。     

RABiTS法涂层导体镍基带的研究进展

轧制辅助双轴织构基带(RABiTS)法是一种经济、高效的生产第二代高温超导涂层导体基带的方法.综述了适用于RABiTS方法的第二代高温超导涂层导体镍基带的研究现状与最新进展,系统分析了合金元素、变形工艺、热处理工艺等对各种镍基带获得立方织构的影响,评述和展望了适用于RABiTS方法的第二代高温超导涂层导体镍基带的发展前景.     

涂层导体用织构复合基带的界面及其扩散行为

复合基带是一种高强、低磁并较易形成锐利立方织构的高性能织构金属基带,能够较好地满足制备高性能涂层导体用织构基带的要求.采用放电等离子烧结方法制备了Ni5W/Ni12W/Ni5W复合基带并对其内外层界面进行了研究,发现扩散界面有利于外层合金立方织构的形成.同时,将基带在1250℃分别经60,120和180 min热处理后,基带外层合金立方织构含量均保持在98％以上.分析表明,在高温热处理阶段复合基带中界面处发生了元素互扩散行为,W元素由芯层扩散至基带表层并在晶界出形成钉扎点,抑制了晶粒的异常长大现象,使复合基带外层合金立方织构在高温热处理阶段具有较好的稳定性.     

YBCO厚膜Ni基带中立方织构的体积分数

给出了根据极图计算ＹＢＣＯ厚膜用Ｎｉ基带中立方织构体积分数的原理、计算公式以及实际操作方法。根据实验数据所进行的计算结果表明,这种方法具有较高的可信度,原则上也适用于其它种类织构体积分数的评估。     

Effect of hot finishing rolling on cube texture in high purity aluminum foils

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｒｅｓｅａｒｃｈｅｓａｂｏｕｔｔｅｘｔｕｒｅｓｆｏｒｍａｔｉｏｎｉｎｐｕｒｅＡｌｈａｖｅｂｅｅｎｍａｄｅｆｏｒａｌｏｎｇｔｉｍｅ .ＩｔｈａｓｂｅｅｎｄｅｍｏｎｓｔｒａｔｅｄｔｈａｔｔｅｘｔｕｒｅｓｉｎｐｕｒｅＡｌｗｅｒｅｍａｉｎｌｙａｆ ｆｅｃｔｅｄｂｙｃｈｅｍｉｃａｌｃｏｍｐｏｓｉｔｉｏｎｓ[1] ,ｈｏｔｒｏｌｌｉｎｇｔｅｍ ｐｅｒａｔｕｒｅ ,ｆｉｎａｌｃｏｌｄｒｏｌｌｉｎｇｒｅｄｕｃｔｉｏｎ ,ｉｎｔｅｒｍｅｄｉａｔｅａｎｎｅａｌｉｎｇｔｅｍｐｅｒａｔｕｒｅａｎｄｆ…     

Fabrication of aluminum matrix composite reinforced with carbon nanotubes

1.0wt.% carbon nanotube （CNT） reinforced 2024Al matrix composite was fabricated by cold isostatic press and subsequent hot extrusion techniques. The mechanical properties of the composite were measured by a tensile test. Mean-while,the fracture surfaces were examined using field emission scanning electron microscopy. The experimental results show that CNTs are dispersed homogeneously in the composite and that the interfaces of the Al matrix and the CNT bond well. Although the tensile strength and the Young’s modulus of the composite are enhanced markedly,the elongation does not decrease when compared with the matrix material fabricated under the same process. The reasons for the increments may be the extraordinary mechanical properties of CNTs,and the bridging and pulling-out role of CNTs in the Al matrix composite.     

预烧结温度对热等静压法制备Co基金刚石串珠性能的影响

采用合适的工艺流程及参数,将热等静压(Hot Isostatic Pressing,HIP)技术应用于Co基金刚石串珠制备。分析了HIP后胎体性能的变化,并通过扫描电镜(Scanning Electron Microscope,SEM)进行断面微观分析。结果表明:相比较热压烧结,HIP更有助于改善Co基胎体各项性能,对于实验中各组Co基胎体,750℃预烧结胎体的性能提高最多,其中胎体抗弯强度提高了25.2%,胎体对钢基体的夹持力提高了37.9%。显然,HIP可用于Co基金刚石串珠的制备,而预烧结温度对HIP后胎体性能有着重要影响,在合适的预烧结温度下可以获得最佳性能的胎体。     

Development of cube texture in multistage annealing of high purity aluminum foils

1　INTRODUCTIONThecubetextureisimportanttohighpurityalu minumfoilsforhighvoltagecapacitorsbecauseitcanenlargeeffectivesurfaceofaluminumfoilsandin creasecapacitancethroughchanneletching .Inordertoincreasethevolumefractionofthecubecompo nent ,a greatdealofresearchesontheformationmechanismofcubetexturehavebeendone ,andmanymethodswere proposed ,suchasimpuritycontrol ling[1,2 ] ,directionalsolidification[3] ,preheating[4 ] ,inhomogeneousrolling[5] ,vacuumannealing[6 ] andsoon .Inthispaperamulti…     

Formation of recrystallization cube texture in high purity face-centered cubic metal sheets

An investigation on recrystallization textures in high purity face-centered cubic (fcc) aluminum, copper, and nickel indicated that the cube texture is a unique dominant final texture. In a macroview of rolling deformation, a balanced activation of four slip systems can result in certain stability of some substructure with cube orientation in the deformed matrix. In the stable substructure the dislocation density is very low, and the dislocation configuration is rather simple in comparison to other orientations so that the cube substructure can easily be transformed into cube recrystallization nuclei by a recovery process. A high orientation gradient and correspondingly high angle boundaries to the deformed matrix are usually expected around the cube nuclei, which, therefore, grow rapidly. After the primary recrystallization, the size of cube grains is much larger than the grains with other orientations, which will be expensed as the cube grains grow further, so that the cube texture can finally become a dominant texture component.     

Fabrication of in-situ synthesized ceramic reinforced Ni-based alloy composite coatings by reactive braze coating processing

In-situ synthesized ceramic such as TiC, Cr7C3 and Cr5B3 reinforced Ni-based alloy composite coating was fabricated on the surface of mild steel substrate by reactive braze coating processing with colloidal graphite, Cr, Ni, ferro-boron, Si and titanium powders as the raw materials at low temperature of 1 000 ℃, and a new kind of coating materials was developed. By means of SEM, EDS, XRD and surface hardness tester, the microstructures, phases, hardness and wear-resistance of the coating were analyzed, respectively. The results revealed that the coating was mainly composed of the ceramic in-situ synthesized reinforcement phases of TiC, Cr7C3 and Cr5B3 and the binder phases in-situ synthesized of Ni31Si12 and (Ni, Fe) solid solution; The ceramic reinforcement phases of TiC, Cr7C3 and Cr5B3 were randomly distributed in the binder phases of Ni31Si12 and (Ni, Fe) solid solution; The coating had about 15vol% pores and can possibly be applied as a self-lubrication coating; The coating and the substrate were integrated together by metallurgical bonding; The coating had a hardness up to 91-94HR15N.     

热等静压处理ZTC4钛合金低温热处理过程中组织演变

研究了低温热处理后热等静压处理的ZTC4的组织演变规律。利用光学显微镜(OM)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)分析了不同尺度的组织特征。研究结果表明:原始组织由粗大的β晶粒和不同取向的α、β片层组成;温度由100℃升高到300℃,组织形态基本没有变化;当热处理温度在400℃时,α、β片层的形态由均匀变为不均匀。元素的微区扩散是造成这种现象的主要原因。     

C/C复合材料与镍基高温合金GH3128钎焊

在连接温度为1 170 ℃、保温时间为60 min的条件下,采用BNi2钎料对C/C复合材料和GH3128进行真空钎焊. 利用扫描电镜、能谱仪和X射线衍射仪对接头的界面组织及断口形貌进行分析. 结果表明,在钎焊过程中,Cr原子向C/C 复合材料侧聚集,并与C原子发生反应生成Cr₃C₂,改善了BNi₂钎料对C/C 复合材料的润湿性,从而实现了C/C复合材料与镍基高温合金GH3128的良好结合;C/C复合材料/BNi2/GH3128钎焊接头区域生成Cr₃C₂,MC,M₃Ni₂Si,Cr₇C₃,MB等反应产物. 接头的断裂位置发生在靠近C/C复合材料的焊缝区域,接头的抗剪强度为24 MPa.     

Microstructure and texture development of pure aluminum and aluminum alloy processed by high speed hot rolling

The microstructure and texture development of pure aluminum and aluminum alloy processed by high speed hot rolling are investigated. The aluminum sheets are rolled at temperatures ranging from 410°C to 560°C at a rolling speed of 15m/s without lubrication and quenched into water at an interval of 30 ms after rolling. The redundant shear strain induced by high friction increases beneath the surface at a reduction above 50% for Al alloy (AA5052) and above 60% for pure Al (AA1050). Dynamic recrystallization occurs in the surface region when the equivalent strain exceeds a critical value that depends on rolling temperature, while only recovery occurs in the center region. The critical equivalent strain for the occurrence of recrystallization in AA5052 is lower than that in AA1050. When the large strain is introduced beneath the surface, the shear texture, the main components of which are {001}<110> and {111}<110>, develops. In the center region, Cu-orientation and cube orientation develop. The shear texture beneath the surface is weak when recrystallization occurs.     

Mechanism of strengthening of cube texture for high purity aluminum foils by additional-annealing

1　INTRODUCTIONHighpurityaluminumfoilsareusedastheanodematerialofhighvoltageelectrolyticcapacitorswhichneedstrongcubetexture { 0 0 1}〈10 0〉forlargeeffec tivesurfacefromchanneletching[1] .Becauseofitstechnicalimportance ,alotofeffortshavebeenmadetodevelopstrongcubetextureinhigh purityalu minumfoils[2 8] .Itwasfoundthatthecubetextureinthefoilscanbestrengthenedviaanannealingpro cessfollowedbyalowcoldrolling[7,8] ,andsuchanannealingiscalledadditional annealinginthispaper .Buttherewerefewinv…