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11.
Y. C. Lee Ph.D. Nagesh Basavanhally Ph.D. 《JOM Journal of the Minerals, Metals and Materials Society》1994,46(6):46-50
In addition to providing electrical connections, solder is useful in the formation of passive, precision alignments for optoelectronic packaging. Different designs have demonstrated micrometer-level alignment accuracies, and the aligned structures are becoming more and more complex. Solder engineering has been successfully introduced into the field of optoelectronics, and it is expected to be applied to many other areas demanding low-cost, precision alignments. 相似文献
12.
Hugo E. Delgado Ph.D. Ramanath I. Ramakrishnan M.S. Timothy E. Howson D.E.S. 《JOM Journal of the Minerals, Metals and Materials Society》1994,46(9):21-23
Computer-aided engineering tools are routinely used to simulate forging and heat-treatment operations and to perform thermal and stress analyses. This review gives a few examples of the current uses of process modeling tools and outlines some developing capabilities and near-term applications. 相似文献
13.
14.
Formation mechanism of bainitic ferrite and carbide 总被引:6,自引:0,他引:6
Hong-Sheng Fang Jia-Jun Wang Yan-Kang Zheng Ph.D. 《Metallurgical and Materials Transactions A》1994,25(9):2001-2007
Superledges on the broad faces of bainitic ferrite plates have been observed with transmission electron microscope (TEM).
The observed superledges, ranging from less than 1 to 24 nm in height, are imaged in three dimension by way of tilt operation
under TEM. Also, an array of smaller superledges are observed to pile up in front of a secondary phase. Pileup of superledges
in front of a barrier is indicative of the mobility of an individual superledge. The precipitation of carbide associated with
bainitic ferrite is also studied. It is observed that a carbide of a wedgelike shape may exist in front of a superledge with
its tip(i.e., thinner end) penetrating the austenite and its root (the other end) originating at α:γ boundary. This condition indicates
that the observed carbides may nucleate at the austenite side of α:γ phase boundary and grow toward austenite matrix.
This article is based on a presentation made at the Pacific Rim Conference on the “Roles of Shear and Diffusion in the Formation
of Plate-Shaped Transformation Products,” held December 18-22, 1992, in Kona, Hawaii, under the auspices of ASM INTERNATIONAL’S
Phase Transformations Committee. 相似文献
15.
Encompassing such versatile analytical techniques as scanning tunneling microscopy and atomic (or scanning) force microscopy, scanning probe microscopes produce high-resolution three-dimensional images. Because of their power as quantitative tools for three-dimensional surface measurement and analysis, the techniques are being used in materials science and engineering for the study of a variety of advanced materials and for investigations into numerous phenomena, including reaction chemistry, crystallinity, kinetics, equilibrium processes, tribology, and conductivity. 相似文献
16.
Three-dimensional, turbulent fluid flow analysis with computational methods has emerged as a viable tool in the design process
of engine components for passenger cars. If applied in the early stages of the component development such analysis can help
reduce the product development time drastically, and may support the design engineer to evaluate several competing design
aspects before product completion. However the grid generation for complex geometries still poses a difficult and time consuming
taks which strongly influences the accuracy of the numerical solution. The present paper studies the numerical solution of
the flow in an inlet-manifold of a five-cylinder engine with two intake-ports for each cylinder. A fast and reliable grid
generation technique is discussed in detail. The finite volume based Navier-Stokes solver with schemes of first and second
order accuracy for the convective terms is used. Numerical results at several mass flow rates and different boundary conditions
at the intake ports are compared with measurements. Finally, the computational results are discussed with respect to their
applicability to support the design process of an inlet-manifold. 相似文献
17.
Mosfata Khattab Ph.D.
F. Choobineh P.E.
Ph.D. 《Computers & Industrial Engineering》1991,21(1-4):291-295Two important characteristics of a project network are the network's topology and the amount of resources available. Most published project scheduling procedures take one or both of these two characteristics into account. Project scheduling procedures that are robust over variations of network characteristics are desirable. The degree of robustness is generally gauged by one or more measures of performance.
The objective of this paper is to compare a set of priority rules that are useful for a single resource project scheduling problem. The set of networks suggested by Patterson (1973) is used along with the set of performance measures proposed by Khattab and Choobineh 1991. The result of this comparison allows one to design a multiattribute heuristic for a single resource project scheduling problem. 相似文献
18.
C. Sarrazin-Baudoux F. Loubat Ph.D. S. Potiron 《Metallurgical and Materials Transactions A》2006,37(4):1201-1209
The influence of gaseous atmosphere on the fatigue crack propagation behavior of a Ti6242 alloy is studied at 550 °C. The
aim of this paper is to obtain reference data in controlled environments at the atmospheric pressure in view of a further
evaluation of the corrosion-fatigue resistance of this alloy in super-critical water medium for a new process for hydrothermal
treatment of organic effluents. Tests were conducted in ambient air, high vacuum, and humidified gaseous atmospheres (80 pct
RH) including pure argon, 80 pct argon + 20 pct oxygen, and 80 pct nitrogen + 20 pct oxygen. The loading specimen was triangular
at a frequency of 0.05 Hz. Some additional tests were performed at frequencies ranging from 0.001 to 35 Hz. The crack propagation
rate is shown to be highly sensitive to the environment, with a predominant detrimental influence of water vapor. A crack
growth model is proposed accounting for the influence of partial pressures of water vapor, oxygen, test, and frequency. 相似文献
19.
Ph. Cassagnau 《Polymer》2008,49(9):2183-2196
The objective of the present work is to investigate, from the open literature, the recent developments in the rheology of silica and organoclay nanocomposites. In particular, this paper focuses on general trends of the linear viscoelastic behaviour of such nanocomposites. Hence, the variations of the equilibrium shear modulus and critical strain (limit of linearity), which depend on power laws of the volume fraction of particles, are discussed as filler fractal structure. In the third section, the strong nonlinearity behaviour (Payne effect) of filled polymers has been discussed in terms of filler nature. Typically two mechanisms arise to depict the linear solid-like behaviour and the Payne effect: particle–particle interactions is the dominant mechanism in fumed silica nanocomposites whereas particle–polymer interaction is the dominant one in colloidal silica nanocomposites at identical filler concentrations. However, these interactions are balanced in each nanocomposite systems by the silica surface treatments (chain grafting, silane modification) and the molecular weight of the matrix. Finally, we aim to unify the main findings of the literature on this subject, at least from a qualitative point of view.We finally report on the thixotropy and modulus recovery after a large deformation in steady and dynamic shear conditions. Following this, the nonlinear rheological properties of nanocomposite materials have been discussed. The discussion is particularly focused on the effect of flow history (transient shear experiments) on the orientation–disorientation of clay platelets. Actually, the linear and nonlinear rheological properties are consistent with a network structure of a weakly agglomerated tactoids. As far as exfoliated clay nanocomposites are concerned, the inter-particle interaction is the dominant effect in the nonlinearity effect. 相似文献
20.