Databases for computational thermodynamics and diffusion modeling

Databases for computational thermodynamics and diffusion modeling can be applied to the prediction of phase diagrams and microstructural evolution. These predictions can be used for alloy and process design, as well as to improve modeling capabilities that would decrease the time for new alloy and process development. Databases that are currently available to scientists, engineers, and students need to be expanded and improved. Accordingly, a workshop was held March 21–22, 2002, to identify the database and information delivery tool needs of industry and education. As a result of the workshop a roadmap was developed to show how these needs can be met during the next decade in a cost-effective way through expanded collaborative efforts in education, basic research, and database development. The workshop consisted of a series of invited talks given to the group as a whole followed by general discussions of needs and benefits, and the construction of a roadmap of future activities. A brief report of a follow-up meeting held on May 27, 2003, is given in the Appendix.     

日本金属热处理未来发展路线概述

本文概要地介绍日本热处理技术协会在2010年制定的金属热处理未来发展路线(Roadmap)。这套日本热处理发展路线重点回顾了日本在近10年来热处理领域的主要研究课题和研究开发成果,详细地分析了目前日本热处理界所面临的问题,提出了今后热处理领域的发展方向。通过对日本热处理发展路线的了解,可以推测出日本在金属材料、机械、汽车、车辆、船舶、重型机械等产业的发展趋势和未来热处理行业将起到的作用。也期待对促进中国热处理技术和制造业的发展有所借鉴。     

数字孪生驱动的车间物流可视化监控方法

为解决数字化车间配送过程不透明、监控手段单一、实时性差、智能化管控难等问题，在分析复杂产品装配车间物流监控需求的基础上，提出一种数字孪生驱动的车间物流配送实时监控方法。构建数字孪生体系框架和运行模式，并对支持该系统实现的车间虚拟建模技术、车间物流实时状态信息处理等关键技术进行了研究。设计并开发了服务系统，实验验证结果表明：采用该监控系统显著提高了车间物流的透明度、实时性、交互性，所提方法可行。     

面向制造企业生产车间知识本体的构建

为了便于准确地表达车间生产管理系统的信息,以及系统与制造企业的其它信息系统集成,本体概念引入到系统中。首先,构建了基于本体的知识集成框架,用于从全局的视角考虑本体开发过程;其次,阐明车间在生产过程中所涉及到的车间领域,论述本体多个层次之间的关系和结构;然后,给出了以车间业务流程为中心的车间本体的元模型,建立了车间本体的体系结构,使得车间本体的建立更加便利和快速;最后,通过应用实例说明本体的建立及表达过程。结果表明,该方法能快速地实现车间本体知识的建立与表达,解决了车间管理系统的信息共享、重用和集成问题。     

铝合金大型复杂薄壁壳体旋压研究进展

大型复杂薄壁壳体是航空航天等高技术产业迅速发展的迫切需求,带横向内筋大型复杂薄壁壳体是其中的典型代表。然而,带横向内筋大型复杂薄壁壳体多道次复合旋压却是一个多因素耦合作用下的复杂塑性成形过程。作者采用数值模拟和实验相结合的方法,以铝合金带横向内筋大型复杂薄壁壳体为代表,建立大型复杂薄壁壳体复合旋压全过程仿真平台与模型,研究不同条件下大型复杂薄壁壳体复合旋压及其特征结构旋压过程中的不均匀塑性变形行为和成形缺陷的形成机理。揭示不同塑性变形行为对工件内筋质量的影响规律,获得对不同塑性变形行为有决定性影响的因素,确定合理的毛坯、工艺和旋轮参数的选择准则。研究结果对发展大型复杂薄壁壳体精确成形技术具有重要的理论意义和实际应用价值。     

基于遗传和声算法的复兴号部件生产车间布局研究

轨道交通装备Z企业是复兴号动车组核心部件供应商，为在发展中保持核心竞争力，企业对工艺、设备、生产规模等各进行优化升级，但却出现原始布局与车间环境升级不匹配的现象，导致生产成本高、工期延时、质量降低等严重问题，布局优化问题亟待解决。针对复兴号核心部件生产车间混合布局的特征，采用基于SLP的遗传和声算法开展布局优化。用SLP方法将作业单位相互关系转化为遗传算法染色体编码，然后以最小化物料搬运成本、最大化车间利用面积为目标函数完成解的寻优。该方法实现了SLP布局方案的快速迭代和精准计算，布局优化后系统的物流、工艺过程、效率、成本等有明显改善，满足企业发展需要，有效提升企业的核心竞争力。     

精益生产在精冲车间的应用

为提高国内精冲行业的生产管理水平,对精益生产在精冲车间的应用进行了研究。对精冲车间进行调研之后发现,工厂目前存在参数难以持续优化、排产订单应变差、生产过程数据获取实时性差等问题。据此,提出了一种在精冲车间应用精益生产的管理模式,基于该模式,使用Microsoft Visual Studio 2013 C#和Microsoft SQL Server 2014开发了一套精冲车间精益生产管理系统。与传统生产管理方式相比,该系统根据精冲生产及行业需求特点,通过数据库分析,能够持续对工艺的生产参数、创新工艺技术进行优化,提高生产能力。采用智能排产技术后,车间能够从容地应对由于市场波动引起的订单变化,降低了中间库存,有效地提升了生产管理效率,有利于国内精冲行业的可持续性发展。     

Emerging Science and Research Opportunities for Metals and Metallic Nanostructures

During the next decade, fundamental research on metals and metallic nanostructures (MMNs) has the potential to continue transforming metals science into innovative materials, devices, and systems. A workshop to identify emerging and potentially transformative research areas in MMNs was held June 13 and 14, 2012, at the University of California Santa Barbara. There were 47 attendees at the workshop (listed in the Acknowledgements section), representing a broad range of academic institutions, industry, and government laboratories. The metals and metallic nanostructures (MMNs) workshop aimed to identify significant research trends, scientific fundamentals, and recent breakthroughs that can enable new or enhanced MMN performance, either alone or in a more complex materials system, for a wide range of applications. Additionally, the role that MMN research can play in high-priority research and development (R&D) areas such as the U.S. Materials Genome Initiative, the National Nanotechnology Initiative, the Advanced Manufacturing Initiative, and other similar initiatives that exist internationally was assessed. The workshop also addressed critical issues related to materials research instrumentation and the cyberinfrastructure for materials science research and education, as well as science, technology, engineering, and mathematics (STEM) workforce development, with emphasis on the United States but with an appreciation that similar challenges and opportunities for the materials community exist internationally. A central theme of the workshop was that research in MMNs has provided and will continue to provide societal benefits through the integration of experiment, theory, and simulation to link atomistic, nanoscale, microscale, and mesoscale phenomena across time scales for an ever-widening range of applications. Within this overarching theme, the workshop participants identified emerging research opportunities that are categorized and described in more detail in the following sections in terms of the following: three-dimensional (3-D) and four-dimensional (4-D) materials science. Structure evolution and the challenge of heterogeneous and multicomponent systems. The science base for property prediction across the length scales. Nanoscale phenomena at surfaces—experiment, theory, and simulation. Prediction and control of the morphology, microstructure, and properties of “bulk” nanostructured metals. Functionality and control of materials far from equilibrium. Hybrid and multifunctional materials assemblies. Materials discovery and design: enhancing the theory-simulation-experiment loop. Following an introduction, these emerging research opportunities are discussed in detail, along with challenges and opportunities for the materials community in the areas of instrumentation, cyberinfrastructure, education, and workforce development.     

铝合金压铸工厂的设计

介绍了某大型铝合金压铸企业新建厂区的设计概况，并具体介绍了压铸车间的工艺设计及工厂的环境保护措施。     

铸造合金凝固组织的计算机模拟与预测

数值模拟技术与计算机技术的迅速发展，使凝固过程的数值模拟正在由宏观向微观转变。微观模拟不仅可以得到材料的凝固组织，而且还能为宏观模拟提供准确的潜热释放信息。对宏观和微观现象的完整耦合可以使我们对铸造凝固过程作出更加准确的模拟预测。针对目前微观组织模拟的研究现状，介绍了几种主要的模拟研究方法，如确定性模拟方法、随机性模拟方法和相场方法等，阐述了其主要特征和模拟微观组织时存在的优缺点，并给出了各种模拟方法的计算实例。由于凝固组织数值模拟的复杂性，对其进行深入的研究是必要的，也是未来计算材料科学的重要发展方向。最后对微观模拟中的问题及发展方向作了分析。     

高等教育质量观的发展与中国的选择

高等教育质量20世纪80年代以来备受关注的问题。高等教育质量观的发展经历了合规定性、合需要性、合创新性等三个阶段。高等教育质量的标准，包括适应性、多样性、发展性三个方面。在当前中国高等教育规模扩大、实现大众化的进程中，要全力以赴地提高高等教育质量，通过高等教育自身的多样化改革适应社会的需要。     

从美国高等教育认证标准看我国高职教育改革

美国高等教育认证标准是院校与认证机构合作制订的 ,它鼓励院校个性发展、强化院校与社会的联系、充分满足学生的需要。值得我国高职教育借鉴的是 :要建立适应市场经济发展要求的非政府性的、中介性的评估机制和机构 ,定期开展对高职院校新办专业办学条件的评估 ,对重点学科、重点实训车间建设的评估 ,对社会服务的评估等 ,促进高职院校专业与职业的信息交流 ,培养个性鲜明、充满活力与创新思维的生产一线技术人才。     

Process Design for Hybrid Sheet Metal Components

The global trends towards improving fuel efficiency and reducing CO_2 emissions are the key drivers for lightweight solutions. In sheet metal processing, this can be achieved by the use of materials with a supreme strength-toweight and stiffness-to-weight ratio. Besides monolithic materials such as high-strength or light metals, in particular metal–plastic composite sheets are able to provide outstanding mechanical properties. Thus, the adaption of conventional, wellestablished forming methods for the processing of hybrid sheet metals is a current challenge for the sheet metal working industry. In this work, the planning phase for a conventional sheet metal forming process is studied aiming at the forming of metal–plastic composite sheets. The single process steps like material characterization, FE analysis, tool design and development of robust process parameters are studied in detail and adapted to the specific properties of metal–plastic composites. In material characterization, the model of the hybrid laminate needs to represent not only the mechanical properties of the individual combined materials, but also needs to reflect the behaviour of the interface zone between them.Based on experience, there is a strong dependency on temperature as well as strain rate. While monolithic materials show a moderate anisotropic behaviour, loads on laminates in different directions generate different strain states and completely different failure modes. During the FE analysis, thermo-mechanic and thermo-dynamic effects influence the temperature distribution within tool and work pieces and subsequently the forming behaviour. During try out and production phase,those additional influencing factors are limiting the process window even more and therefore need to be considered for the design of a robust forming process. A roadmap for sheet metal forming adjusted to metal–plastic composites is presented in this paper.     

机械镀合金镀层的研究进展

首先,概述了近年来国内外对机械镀合金层研究的发展历程,指出不同种类机械镀合金层在湿式与干式工艺中的研究难点,湿式机械镀研究主要集中于镀层形成机理、锌基复合镀层及表面活化剂等,干式机械镀主要集中于镀层的合金化及镀层合金材料的配制方面。其次,分析了2种不同工艺下合金镀层的形成机理及合金镀层的防腐机理,湿式镀层由金属粉依靠表面活性剂和沉积促进剂在先导金属的作用下稳定持续形成,从而在基体表面形成防腐屏障;干式镀层依靠合金包覆的丸粒高速喷射冲击基体而形成,合金层和其表面的氧化膜作为防护层。最后,基于合金镀层优良的耐蚀性能和机械镀工艺特点,给出了研究发展以合金粉为原料的湿式机械镀的倡议,并从活化与沉积稳定性、绿色与复合化、产业标准化等方向,提出了机械镀合金镀层在防腐材料领域的发展趋势及研究建议。     

可重构车间布局建模研究

可重构车间布局是指能够根据生产任务需要而快速组合的一组的加工设备布局。可重构车间布局除了要考虑一般布局问题外,还要考虑未来可能的重构问题。总结可重构车间布局的一般原则,给出车间布局重构问题的一般求解过程。定义重构成本和可重构度的概念,以物流成本最小化和车间布局可重构度最大化为目标,建立可重构车间布局多目标决策模型。     

Modeling of AA5083 Material-Microstructure Evolution During Butt Friction-Stir Welding

A concise yet a fairly comprehensive overview of the friction stir welding (FSW) process is provided. This is followed by a computational investigation in which FSW behavior of a prototypical solution-strengthened and strain-hardened aluminum alloy, AA5083-H131, is modeled using a fully coupled thermo-mechanical finite-element procedure developed in our prior study. Particular attention is given to proper modeling of the welding work-piece material behavior during the FSW process. Specifically, competition and interactions between plastic-deformation and dynamic-recrystallization processes are considered to properly account for the material-microstructure evolution in the weld nugget zone. The results showed that with proper modeling of the material behavior under high-temperature/severe-plastic-deformation conditions, significantly improved agreement can be attained between the computed and measured post-FSW residual-stress and material-strength distribution results.     

镁合金压铸件凝固过程计算机模拟

分析了压铸工艺的特点以及压铸过程数值模拟软件的要求，利用铸造过程分析软件模拟镁合金压铸件凝固过程的温度场，基于温度场分析结果，预测在铸件凝固时形成缩孔、缩松等缺陷的位置及分布，优化铸造工艺设计。     

Effect of process variables on grain growth in simulating solidification microstructure of Ti-45%Al alloy ingot by stochastic model

A comprehensive stochastic model for simulating microstructure formation of Ti-45% Al（mole fraction） alloy ingot during solidification process was developed, based on a finite differential method（FDM） for macroscopic heat flow calculation and a cellular automaton（CA） technique for microscopic modeling of nucleation and growth. The formation of a shrinkage cavity at the top of ingot was taken into account. The effects of process variables such as pouring temperature and mold-preheated temperature on the microstructure formation were investigated. The calculated results indicate that the columnar zone is expanded with increasing pouring temperature in the nonlinear way and the volume fraction of equiaxed zone only slightly varies with the mold-preheated temperature.     

Magnesium Powder Metallurgy: Process and Materials Opportunities

The major efforts in magnesium alloy development for automotive applications have concentrated on creep resistant alloys produced by permanent mould and high-pressure die casting routes. While large components, such as crankcases, will never be produced by powder metallurgy, there are smaller components in and around the powertrain which could be fabricated from powder precursors. This article will explore the potential of some of the more recent powder compaction developments, and discuss the alloy development strategies that emerge for magnesium-based components as a consequence of these process developments. In particular, the viability of direct powder extrusion of semi-finished product, using conventional extrusion or equal channel angular processing, combined with T6 heat treatments, will be considered. This article was presented at Materials Science & Technology 2007, Automotive and Ground Vehicles symposium held September 16-20, 2007, in Detroit, MI.     

Design considerations for developing biodegradable and bioabsorbable magnesium implants

The integration of biodegradable and bioabsorbable magnesium implants into the human body is a complex undertaking that faces major challenges. Candidate biomaterials must meet both engineering and physiological requirements to ensure the desired properties. Historically, efforts have been focused on the behavior of commercial magnesium alloys in biological environments and their resultant effect on cell-mediated processes. Developing causal relationships between alloy chemistry and microstructure, and effects as a cellular behavior can be a difficult and time-intensive process. A systems design approach has the power to provide significant contributions in the development of the next generation of magnesium alloy implants with controlled degradability, biocompatibility, and optimized mechanical properties, at reduced time and cost. This approach couples experimental research with theory and mechanistic modeling for the accelerated development of materials. The aim of this article is to enumerate this strategy, design considerations, and hurdles for developing new cast magnesium alloys for use as biodegradable implant materials.