Advanced Materials for Land Based Gas Turbines

The gas turbine (Brayton) cycle is a steady flow cycle, wherein the fuel is burnt in the working fluid and the peak temperature directly depends upon the material capabilities of the parts in contact with the hot fluid. In the gas turbine, the combustion and turbine parts are continuously in contact with hot fluid. The higher the firing temperature, higher is the turbine efficiency and output. Therefore, increasing turbine inlet temperature (firing temperature) has been most significant thrust for gas turbines over the past few decades and is continuing in pursuing higher power rating without much increase in the weight or size of the turbine. Firing temperature capability has increased from 800 °C in the first generation gas turbines to 1,600 °C in the latest models of gas turbines. Higher firing temperatures can only be achieved by employing the improved materials for components such as combustor, nozzles, buckets (rotating blades), turbine wheels and spacers. These critical components encounter different operating conditions with reference to temperature, transient loads and environment. The temperature of the hot gas path components (combustor, nozzles and buckets,) of a gas turbine is beyond the capabilities of the materials used in steam turbines thus requiring the use of much superior materials like superalloys, which can withstand severe corrosive/oxidizing environments, high temperatures and stresses. However, for thick section components such as turbine wheels, which require good fracture toughness, low crack growth rate and low coefficient of thermal expansion, alloy steels are extensively used. But the wheels of latest models of gas turbines, operating at very high firing temperatures (around 1,300–1,600 °C), are made of superalloy, which offers a significant improvement in stress rupture, tensile and yield strength and fracture toughness required for the application.     

工厂原料工段的总图运输设计

总图运输设计是工业建筑整体规划设计中的一项重要工作,文章通过某工厂原料工段的设计,介绍了在工程设计前期的总图设计方法.     

Synchrotron X-Rays for Microstructural Investigations of Advanced Reactor Materials

X-rays from synchrotron beamlines provide a powerful tool for materials analysis in circumstances where long-term materials degradation under complex loading conditions (e.g., temperature, irradiation, and stress) becomes important. This may occur for advanced gas cooled reactors. Synchrotron X-rays can help to improve lifetime assessments by providing a more in-depth understanding of microstructural damage. This article summarizes results of X-ray absorption fine spectrum analysis and X-ray magnetic circular dichroism synchrotron techniques. They were employed to evaluate various microstructural features, which are important in understanding the lifetime of materials exposed to extreme conditions. Dispersoid strengthening by yttria particles, conditions that produce nanocrystal Zircaloy, and the role of magnetism on the stability of ferritic steels were taken as examples.     

Deflection Requirements for Bridges Constructed with Advanced Composite Materials

Many bridges in the United States have reached or are approaching the end of their useful lives. Since the 1940s, salt and other deicing agents applied to highways and bridges, coupled with inadequate maintenance funding, have led to the premature deterioration of many bridges. Growth of the United States economy and population has increased vehicular traffic volume and loads. For these reasons, the need exists for large-scale rehabilitation, strengthening, widening, and replacement of bridges. The financial cost to society to replace these bridges or to rehabilitate them conventionally is staggering. What is needed are low cost, durable methods of strengthening current bridges, extending their lives so that state departments of transportation may spread out the process of eventual replacement. In constructing new bridges, better materials or designs are needed so we may avoid tomorrow the consequences we are experiencing with today’s bridges. Polymer matrix composites offer that potential. A design methodology developed for composite bridges is based on limiting live load deflections. This paper focuses on the establishment of deflection limitations for bridges constructed with advanced composite materials, based on limiting response accelerations produced by the passage of truck traffic.     

Materials Challenges for Advanced Combustion and Gasification Fossil Energy Systems

This special section of Metallurgical and Materials Transactions is devoted to materials challenges associated with coal based energy conversion systems. The purpose of this introductory article is to provide a brief outline to the challenges associated with advanced combustion and advanced gasification, which has the potential of providing clean, affordable electricity by improving process efficiency and implementing carbon capture and sequestration. Affordable materials that can meet the demanding performance requirements will be a key enabling technology for these systems.     

Serration and Noise Behavior in Advanced Materials

正The Chinese Materials Research Society(C-MRS)Conference(2015)was held in the Guizhou Park Hotel International Conference Center,Guiyang,China,from July 10-14,2015.This conference consists of 30symposia,including 4international symposia.As one of 4international symposia,"Serration and noise behavior in advanced materials"     

Applications of X-Ray Characterization for Advanced Materials in the Electronics Industry

Nanometer thick films, quantum dots, and quantum wires are the basis of the modern electronic industry. X-ray diffraction techniques play an increasingly important role as basic characterization tools for determining detailed structural information of ultrathin film such as the evolution of strain relaxation, defect formation, film/substrate interfacial properties, and the effects of the reduced dimensionality and structural correlations to electrical properties. Materials of technological interest are SiGe and strained Si; artificial substrates such as silicon on insulator; high- and low-κ dielectric materials, which will substitute SiO₂; materials for interconnects; new materials for memory storage; micro-electro-mechanical systems (MEMS); and photovaltaics. An overview of the major X-ray scattering applications of interest to this industry will be presented in this article.     

先进钢铁材料及其生产技术进步

在可预见的未来，钢铁材料仍然是社会和经济发展所需的最重要结构材料。先进钢铁材料的发展必须要满足社会对其生产、使用和回收等环节提出的节能源、节资源和一举呆要求。为此，先进钢铁材料将向高性能、长寿命、低成本、易加工、多品种以及具有绿色环保意义的柔性、可控、实时制造方向发展。概述了先进钢铁材料及其生产技术的最新进步。     

2011年云南金属材料与加工年评

以2011年云南省材料科研工作者所发表的文献为依据,对材料科学的文献综述、基础理论研究、黑色金属、有色金属、稀贵金属和其它材料进行了评述。     

Hydrometallurgical Processing Routes in the Synthesis of Advanced Materials

Abstract

Hydrometallurgical processing routes show outstanding potential for synthesizing a wide range of advanced ceramic and metallic materials, in which the composition, purity and structure are closely controlled to produce- materials with the properties needed for specific applications. The characteristics of "advanced materials'* are first discussed in general terms. Those classes of materials most likely to be amenable to hydrometallurgical processing are then considered, and the economic, technical and environmental benefits that might be derived from adopting hydrometallurgical processing routes are discussed. The thermodynamic, surface chemical, kinetic, and transport principles that could be used to control the materials characteristics are then reviewed. Finally, selected examples of aqueous processing techniques for preparing both oxide ceramics and metallic materials, as powders, films or coatings, are provided.     

用先进表面工程服务新材料产业发展

表面工程作为21世纪工业发展的关键技术之一，是先进制造技术的重要组成部分，可为先进制造技术的发展提供技术支撑。表面工程具有广泛的功能性、潜在的创新性、环境的保护性、很强的实用性和巨大的增效性，因而受到各行各业的重视。考虑到目前包括东北在内许多老工业基地的工业技术落后、装备陈旧、产品老化的现状，而我省在表面工程方面又拥有较强的人才优势、技术优势和产学研优势，并有一些先进成熟的表面工程技术。作者认为充分发挥表面工程的特点与优势，必将为我省新材料产业的振兴、为老工业基地的振兴起到很好的服务作用。     

Foreword: Neutron and X-Ray Diffraction Studies of Advanced Materials

Symposium: Neutron and X-Ray Diffraction Studies of Advanced Materials

Foreword: Neutron and X-Ray Diffraction Studies of Advanced Materials     

Research and Development of Rare Earth Advanced Materials in China

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Advanced Testing and Characterization of Asphalt Concrete Materials in Tension

The modeling of asphalt concrete materials is currently handled using linear viscoelasticity (VE) and viscoplasticity (VP) with damage. Exploratory frequency sweep and creep and recovery test results indicate that the linear VE with damage theory cannot represent the material response unless damage–healing is also included in the formulation. Therefore, the concept of effective stress, used for modeling damage, is extended to include additional nonlinear effects. A new theory of nonlinear VE with damage and VP is presented for uniaxial loading conditions in tension. A special load transfer device is described. It allows very fast unloading and very long recovery periods with complete unloading. It permits better separation between VE and VP components. Using this device, a uniaxial tension creep and recovery test is conducted and analyzed. The nonlinear material response is illustrated and a calibration of the damage function is presented. The formulation is being extended to three-dimensional conditions.