Processing,deformation, and failure in superplastic aluminum alloys: Applications of orientation-imaging microscopy

The importance of grain size refinement in enabling superplasticity is reviewed, and the current understanding of grain boundary characteristics is summarized. The application of orientation-imaging microscopy (OIM) methods to the processing response and the deformation and failure modes in superplastic aluminum alloys are illustrated through microtexture analysis and determination of grain boundary characteristics in selected commercial materials. Continuous and discontinuous recrystallization reactions exhibit distinct microtextures and grain boundary characteristics. The application of OIM and microtexture analysis to the evaluation of both deformation and failure mechanisms during superplastic forming is illustrated. This paper was presented at the International Symposium on Superplasticity and Superplastic Forming, sponsored by the Manufacturing Critical Sector at the ASM International AeroMat 2004 Conference and Exposition, June 8–9, 2004, in Seattle, WA. The symposium was organized by Daniel G. Sanders, The Boeing Company.     

Study of δ-hydrides in Ti-2Al-2.5Zr and Ti-4Al-2V alloys

The α alloy Ti-2Al-2.5Zr and near α alloy Ti-4Al-2V were hydrogenated to various levels. The morphology,orientation relation (OR), and habit plane of the hydrides were studied by means of transmission electron microscopy (TEM). It was found that in the two alloys most of the precipitates are δ-hydrides which have fcc structure with the lattice parameter a = 0.44 nm. Two basic orientation relationships and habit planes of the precipitates are determined. Twin structure was observed in both alloys.     

稳定冷轧轴承钢带球化退火工艺

对冷轧真空精炼轴承钢带的球化退火工艺进行了试验，并探讨了冷轧和热处理工艺对球化的影响，得出了较为理想的球化退火工艺和退火后的性能，并取得了较好的经济效益。     

Dislocation Structures in a BulkPb－doped Bi－SrCa－Cu－O High Temperature Superconductor

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HIGH RESOLUTION STUDY OF TWINS IN Al_(20)Cu_2Mn_3 PHASE

The dispersoid phase Al_(20)Cu_2Mn_3 in a 2024 Al alloy is commonly composed of twins,An ob-servation of corresponding high resolution image shows that the twin boundary plane is a glideplane other than mirror one.Two neighbouring components of twins are not symmetry of re-flection or rotation,but of glide reflection.The“diamond”glide plane is(101)and the glidevector is(1/4)(-).Components of twins in the phase take shape of prism with thelongitudinal edge being parallel to[010]and side faces being{101}and{100}.     

折板跌落式竖井设计约束条件研究

结合国内深层隧道排水工程-广州市东濠涌深层排水隧道,通过物理模型试验探讨了不同折板间距情况下折板竖井消能规律,并根据竖井中水流在折板间需满足的过流能力及充分消能的约束条件,研究了折板竖井消能的最大过流流量及稳定消能边界,提出了折板竖井设计应同时满足的约束条件以及折板通气孔的推荐位置。研究表明,在折板间距与折板宽度的比值小于0.408时,约束条件只有最大过流能力;当比值大于0.408时,只需考虑充分消能的约束条件。     

An effective MBSE approach for constructing industrial robot digital twin system

Recently, the rapid development of digital twin (DT) technology has been regarded significant in Cyber-physical systems (CPS) promotion. Scholars are focusing on the theoretical architecture and implementing applications, in order to establish a high-fidelity, dynamic, and full-lifecycle DT model and achieve a deep fusion of real and virtual. As a typical complex system with multi-disciplines, multi-physics, and multi-domain characteristics, industrial robot (IR) involves various processes and elements from the two other levels of the system: components and production lines. Their complex relationships lead to a huge challenge to build a comprehensive DT model. Current researchers usually concentrates on single-layer services because of limited construction methodology, which results in enormous isolated models, and leads to low reusable system blocks, finite scalability, and high costs of design, adjustment, upgrade, and maintenance. To address these issues, a standardized methodology and a hierarchical, modular, and generic architecture are proposed to depict comprehensive and variable industrial robot digital twin (IRDT). Firstly, the ontology information model is presented by analyzing variable factors systematically. Then, model-based system engineering (MBSE) based methodology is introduced, including construction process and variants management. After modeling process of three levels (problem domain, solution main, and implementation domain) and four viewpoints (requirement, structure, behavior, and parameter), a generic architecture of IRDT is constructed and a feature-based variants management method is described. Besides, a six-axis IRDTS is implemented to illustrate the mapping of logical architecture and physical system as a multi-level elements and processes representation example. And the steps of numerical evaluations consist of system delay and derivation. Finally, results show the effectiveness and the potential of the proposed theoretical methodology for constructing IRDTS and other industrial applications.