Mullite短纤维/Al-Cu-Mg复合材料界面微结构研究

研究用挤压铸造方法制备Mullite/Al-Cu-Mg复合材料,用透射电镜(TEM)观察了淬火态及时效态复合材料的微观组织.结果表明,莫来石(Mullite)短纤维组织致密但分布不均;在淬火态复合材料纤维/基体界面和Si晶体/基体的界面附近基体一侧中发现存在高密度位错;Mullite/Al-Cu-Si复合材料的界面以非平衡共晶MgAl2O4沉淀相为主.     

铸造莫来石短纤维/Al-4.5Cu复合材料界面微结构的研究

用挤压铸造方法制备Mullite/Al-4.5Cu复合材料.用透射电镜(TEM)观察了淬火态及时效态复合材料的微观结构.结果表明:莫来石(Mullite)短纤维组织致密但分布不均;淬火态复合材料界面附近基体一侧存在高密度位错;Mullite/Al-4.5Cu复合材料有界面反应发生,生成CuAl2O4;时效态复合材料界面处还存在明显的无析出物带.     

莫来石短纤维增强Al—0.95Mg—0.85Si复合材料的时效行为研究

用挤压铸造方法制备Mullite/Al-0.95Mg-0.85Si复合材料。用硬度测试、差示扫描量热仪（DSC）和透射电镜（TEM）等手段,研究了莫来石短纤维增强Al-0.95Mg-0.85Si复合材料及其基体合金的时效行为。结果表明：无论是复合材料还是基体合金,它们都具有相似的时效硬化曲线及相同的析出序列;Mullite纤维的引入明显提高了基体合金的时效硬度,并一定程度地加速了Al-0.95Mg-0.85Si合金的时效硬化过程,但对低温下由空位扩散控制的SSS→GP反应无明显抑制;温度对复合材料及其基体合金时效硬化行为的影响基本一致。     

纤维及界面反应对mullite／Al—4.0Cu—1.85Mg铝基复合材料时效行为的影响

采用挤压铸造方法制备mullite/Al-4.0Cu-1.85Mg铝基复合材料。用硬度测试（HB）,差示扫描量热仪（DSC）和分析透射电镜（ATEM）等手段,研究了复合材料及其基体合金的时效硬化特性,时效相的析出序列,析出相和位错的微观形貌特征以及界面结构,结果表明：mullite纤维的引入抑制了GPB区的形成,提高了基体合金的时效硬度,但纤维加速复合材料时效硬化的作用不明显,这是由于Mg元素在纤维／基体界面处发生了界面反应,生成镁铝尖晶石（MgCl2O4),使复合材料中非纤维区内实际Mg含量降低所致。     

Mullite/A1-4.5Cu复合材料中莫来石纤维及界面反应产物研究

用挤压铸造方法制备莫来石（Mullite）短纤维增强A1-4.5Cu复合材料;用X射线衍射仪（XRD）和分析透射电镜（ATEM）对复合材料中纤维的微观结构、复合材料界面及界面反应产物的结构特征、化学组成进行了研究。结果表明,莫来石短纤维由大小不等的小晶粒组成,晶型为正交晶系;复合材料界面存在断续分布的CuAl2O4尖晶石结构的界面反应产物。     

含Si量对Mullite纤维/Al-Cu-Si复合材料及其基体合金时效行为的影响

用挤压铸造方法制备了Mullite/Al Cu Si复合材料。用硬度 (HB)测试仪、差示扫描量热仪 (DSC)和显微镜研究含Si量变化和Mullite纤维对Al Cu Si合金时效硬化行为的影响 ;元素Si、Mullite纤维以及二者同时存在对Al Cu Si合金时效析出序列的影响。结果表明 :Si和Mullite纤维明显抑制了Al Cu合金GP区的形成 ;随着含Si量增加 ,Al Cu Si合金的时效硬化过程加快 ;Mullite纤维对Al Cu和Al Cu Si合金的时效硬化过程都具有加速作用 ,同时提高了基体合金的时效硬度 ,但相对而言 ,Mullite纤维对无Si的Al Cu合金的时效硬化加速作用更为明显一些。     

Mullite/ZL101复合材料的组织及时效特性

用挤压铸造制备Mullite/ZL101复合材料。用光学显微镜及透射电镜（TEM）观察复合材料及其基体合金的微观组织，用硬度测试及差示扫描量热仪研究Mullite/ZL101复合材料及其基体合金的时效特性。结果表明：采用挤压铸造法可获得复合良好的Mullite/ZL101复合材料，Mullite纤维对ZL101合金有明显的强化作用；在整个时效过程中，复合材料的时效硬度明显高于基体合金，纤维的引入没有改变基体合金时效析出序列，对低温下由空位扩散控制的SSS－GP反应无明显的抑制作用；复合材料中β″析出反应的峰值温度及活化能较基体合金的低，时效硬化过程得到一定程度的加速。     

纤维增韧碳化硅陶瓷基复合材料的界面区研究

在连续纤维增强陶瓷基复合材料中，界面调节脆性基体与脆性纤维之间匹配关系的功能以及自身特有的物理化学性质，决定着复合材料的整体综合效能。本研究从实践中发现界面区的存在，并尝试提出界面区的概念。界面区是具有一定厚度，含有两处界面（界面相／基体和界面相／纤维）和体相（界面相）的区域。采用透射电子显微技术从微结构的角度研究了3DC／SiC内界面区与裂纹的相互作用行为。TEM观察表明，由于裂纹偏斜／贯穿竞争随时空的推演，基体主裂纹会在界面区的多处位置产生单多重偏斜、裂纹尖端前方应力集中诱发脱粘和开裂、纳米尺度微裂纹桥连等相互作用，其发生的具体部位和方式由界面区内各种相关界面（或断裂）韧性共同决定。此外，结合影响因素的讨论，初步建立起3DC／SiC内基体裂纹与界面区相互作用的物理模型。     

SiCp/ZL109复合材料界面研究

本文用TEM研究了用旋涡搅拌法制造的SICP／ZL109复合材料的界面,发现SiCP与基体界面无反应产物生成,界面结合致密,硅容易在碳化硅表面结晶或折出,在SiCp／AL界面的基体（AL）一侧,存在着衍射衬度不同的“亚晶铝带”,其中存在大量位错,SiCp／AL之间和SiCp／Si之间不存在固定的、低指数的晶体学位向关系,在SiCp与基体界面,发现了解理小刻面,这些小刻面的存在为进一步研究位向关系提供了方便。     

喷涂法制Mo丝增强NiAl单层复合材料的研究

采用等离子喷涂工艺，制备了Mo丝增强的NiAl基单层复合材料。系统地研究了该复合材料的显微组织，Mo丝／NiAl界面的结合特性以及在不同热处理状态下复合材料的界面行为。研究表明：制备态单层复合材料的基体由强烈变形（扁平化）和高速结晶的NiAl熔滴颗粒形成的层状结构构成，颗粒间有较多的分界面，Mo丝／基体的界面结合强度不高，其结合为非冶金结合。800℃，3h退火后，Mo丝／基体界面的结合情况得到改善，复合材料的性能提高。更高温长时处理后，基体元素Ni在Mo丝中形成扩散层，在界面处基体一侧和基体中结晶的熔滴颗粒分界面处的铝的氧化物层明显增厚。     

钢-铝铅半固态铸轧复合界面研究

针对钢-铝铅半固态复合界面的特点,采用界面铁铝化合物比率对钢-Al-28Pb半固态铸轧复合界面进行了定量研究,并且利用人工神经网络技术建立了界面铁铝化合物比率与复合参数(如钢板预热温度、Al-28Pb半固态浆料固相率、铸轧速度等)之间的关系模型.结果表明:与复合界面最大界面剪切强度相对应的界面铁铝化合物比率为71.5%,也就是说,合理的钢-Al-28Pb半固态铸轧复合界面应由71.5%的铁铝化合物构成.     

Ce及Mg对SiCp/Al复合材料界面润湿性的影响

采用液态搅拌法制备了SiCp/ZL105复合材料,并对其界面行为进行了研究.试验结果表明,表面活性元素Mg的加入能降低铝合金熔体的表面张力,进而改善SiC颗粒与铝基体间的界面润湿性,增强SiC颗粒与基体间的浸润复合;而加入富铈混合稀土后没有收到明显的效果.分析认为,Mg对铝液表面张力及其在颗粒表面润湿性的改善是通过在颗粒与熔体间引发了化学反应达到的,并非仅物理作用.在本试验条件下,Mg的加入引发了MgAl2O4在颗粒表面的生成,达到了改善界面润湿性的效果;而富铈稀土加入后,未在SiC颗粒与铝熔体间引发界面反应.     

Evolution,Control,and Effects of Interface in CNT/Al Composites:a Review

This review summarizes the work carried out in the field of interface study in carbon nanotube reinforced aluminum(CNT/Al) composites. Much research work has been conducted to reveal the evolution of CNT/Al interface in producing the composite with the purpose of achieving uniform distribution of CNTs and tight interfacial bonding. The effect and principles of coating were reviewed along with the illustration of ‘‘intermetallic interphases' ' design. Different roles of CNT/Al interface in structural and functional application were elucidated, and the future work that needs attention was addressed.     

计算机通信技术在压力机参数测量中的应用

介绍了ＰＣ机与单片机通信技术在曲炳压力机多项参数测量中的应用,并对其通信接口的设计方法做了阐述。     

TGO厚度和界面形貌对新型涂层双管系统应力分布的影响

以700℃新型涂层双管系统为研究对象,采用有限元顺次耦合的计算方法,开展了热机载荷作用下TGO厚度和界面形貌对系统应力分布的影响研究。结果表明:TGO的厚度与其界面粗糙度均会对系统的Mises应力分布产生影响,但是与TGO厚度相比,粗糙度对TGO/BC界面靠近波峰处的Mises应力影响更加显著。此外,在TGO界面幅值和波长一定的条件下,不同的界面波形排列不会直接影响系统TGO/BC界面波峰处的Mises峰值应力;由于幅值和波长变化有效地改变了TGO界面的曲率,它们是控制涂层双管系统TGO/BC界面应力分布的关键特征参量。     

基于Win95的车床数控界面系统的研究

介绍一种以工业控制计算机和Ｗｉｎ９５为开发平台所开发的车床数控界面系统,其功能模块划分以及典型功能模块的实现。     

Thermodynamically consistent phase field approach to phase transformations with interface stresses

Thermodynamically consistent phase field theory for multivariant martensitic transformations is developed with the main focus on introducing correct interface stresses (tension). The nontrivial point is that the interface tension (physical phenomenon) is introduced with the help of some geometric nonlinearities, even when strains are infinitesimal. Total stress at the diffuse interface consists of elastic and dissipative parts which are determined by the solution of the coupled system of phase field and viscoelasticity equations and the introduced interface stresses. An explicit expression for the free energy is derived that results in the desired expression for the interface stresses consistent with the sharp interface for the propagating nonequilibrium interface. Analytical expressions for nonequilibrium interface energy, width, entropy excess, as well as distribution of the interface tension are derived and parametrically studied. Interface stress tensor distribution is also obtained and analyzed for a critical martensitic nucleus. The possibility of extending the developed approach to other phenomena and more general models is discussed.     

On the co-existence and stability of trijunctions and quadrijunctions in a simple model

Junctions of four domain walls (quadrijunctions) are shown to be stable in Ising-type ordering models with weak first and strong second neighbor interactions that give rise to certain ordered structures with four or more domains, such as the striped rectangular phase on ordering of a two-dimensional square lattice and the B32 (NaTl) structure on ordering of b.c.c. When first neighbor interactions in the model are set to zero, quadrijunctions are stable with respect to dissociation into two trijunctions for all orientations and all temperatures below the critical ordering temperature. When the magnitude of first neighbor interactions in the model is increased, the stable range of orientation for quadrijunctions diminishes, and quadrijunctions co-exist with trijunctions in a microstructure. When the magnitude of the first neighbor interaction reaches the limit of the existence of the ordered phases, the range of orientation for which the quadrijunction is stable vanishes. Results of confirming computer simulations are presented.     

Origin of bistability in polyfluorene-based organic bistable devices

This study examined the origin of bistability in polyfluorene (PFO)-based organic bistable memory devices (OBDs) by changing the bulk properties of PFO and metal electrodes. Two different PFOs with and without internal trap sites and two Al and Au electrodes were used. Bistability was induced in all devices when Al was deposited on PFO. On the other hand, bistable switching was observed only in the PFO device with internal trap sites when Au was deposited on PFO. Therefore, both the formation of internal trap sites and an organic–metal interface are essential for bistability in PFO-based OBDs.     

Haptic Environment for Designing Human Interface of Virtual Mechanical Products

For efficient and high-quality design of mechanical products, it is now possible to use virtual product models as a basis for functional simulation and verification. However it is not easy to evaluate human operational interfaces of such virtual products only by graphical interfaces. In this paper, a method is proposed to simulate human operational interfaces by use of generic haptic devices. Based on behavioural simulation of virtual product models, appropriate information for haptic interaction is generated, and machine operational interfaces are simulated by use of generic haptic devices. For evaluating the effectiveness of the proposed method, assessment of virtual mechanical switching operations has been performed.