超高分子量聚乙烯的剖蚀磨损

用气流喷砂型冲蚀试验装置测试了超高分子量聚乙烯（ＵｌｔｒａＨｉｇｈＭｏｌｅｃｕｌａｒＷｅｉｇｈｔＰｏｌｙｅｔｈｙｌｅｎｅ）的冲蚀磨损性能，考察了冲蚀粒子的入射角，速度，粒子的硬度对冲蚀磨损的影响，用扫描电子显微镜观察冲蚀磨损表面形貌，指出：在高角冲蚀时，磨损机理主要为塑性变形和显微裂纹；在低角冲蚀时，磨损机理主要为显微镜切削和显微犁耕冲蚀磨损机理与冲蚀粒子有关。     

超高分子量聚乙烯的冲蚀磨损

用气流喷砂到冲依试验装置测试了超高分子量聚乙烯（UltraHighMolecularWeightPolyethylen）的冲蚀磨损佳能．考察了冲蚀粒子的入射角、速度、粒子的硬度对冲蚀磨损的影响．用扫描电子显微镜观察冲蚀后报表面形统指出：在高角冲蚀时，摩根机理主要为塑性变形和显微裂纹；在低角冲蚀时，磨损机理主要为显微切削和显微犁耕．冲蚀磨损机理与冲蚀粒子有关．     

固体粒子冲蚀微切削模型的数值模拟研究

气动运输的管道内壁受到粒子冲击会产生冲蚀磨损,通常利用微切削模型来预测其寿命周期。利用ABAQUS/CAE建立塑性材料微切削过程的有限元模型,通过对切削过程中粒子受力分析,研究了冲蚀角和冲蚀速度对磨损率与冲蚀角关系曲线的影响,确立了微切削模型适用的冲蚀角范围。     

材料抗冲蚀性的研究进展

综述了材料内在因素和环境因素变化对冲蚀的影响,韧性材料的耐冲蚀性能优于脆性材料,脆性材料仅在10^0冲蚀角以下才表现出较好的耐冲蚀性;冲蚀下的脆性材料和塑性材料的区分不仅与材料的韧脆性有关,还与冲击粒子的动能有关。当粒子质量发生变化时,材料的冲蚀机理随之变化;影响材料耐冲蚀磨损的重要内在因素是弹性模量而不是硬度;各种冲蚀机理都有一定的适应性和局限性。     

几种工程材料的冲蚀行为的研究

通过对五种工程材料在不同条件下的冲蚀率和磨损表面形貌的分析,研究了冲蚀角度、粒子速度、粒径、质量流量等因素的影响,探讨了材料的磨损机理.     

固体粒子冲蚀磨损研究进展

固体粒子冲蚀磨损是引起材料破坏或设备失效的一个重要原因，本文简要介绍塑性材料和脆性材料的主要冲蚀理论，综述环境因素、粒子性能和材料性质的影响。     

系统方法在冲蚀研究建模中的应用

应用系统方法的灰色系统理论，输入输出模型及回归分析等方法，研究设计并提出了冲蚀研究系统模型、冲蚀机理模型、冲蚀率与冲蚀参数的相关模型，及冲蚀系统各因素交互作用模型，对进一步展开冲蚀研究，研制使用耐冲蚀材料，构筑了简明的模型，阐述了清晰的思路，具有一定的指导意义。     

固体粒子冲蚀磨损理论及影响因素的研究概述

在工农业领域大量存在着固体颗粒物质与机械部件的接触作用,固体颗粒与机械部件不可避免会存在摩擦磨损,从而造成机械零部件磨损失效。总结了前人在各个领域研究固体粒子冲蚀磨损的成果,介绍了影响固体粒子冲蚀磨损的各种因素,最后探讨了固体粒子冲蚀磨损未来可能的发展方向。     

水机运流面的粒子冲蚀强度分析与缓冲涂层试验

本文分析了水机过流面受粒子冲蚀过程的表面接触应力，讨论了表面材料特性对应力水平的影响；指出粒子入射速度0.65m/s左右时碳钢表面即发生屈服，采用弹性缓冲涂层可降低应力两个量级，文中同时介绍了这种缓冲涂层的结构和应用效果。     

氮合金化堆焊硬面合金的抗冲蚀磨损性能研究

利用氮代替部分碳,通过铌、钒、钛固氮形成氮合金化堆焊硬面合金,进行了冲蚀角度30°抗冲蚀磨损性能实验,深入分析了冲蚀磨损机理。结果表明:高速含砂水流的冲击磨损,对硬面合金产生明显切削和犁沟剥落,其磨损机制主要为微切削磨损。氮合金化堆焊硬面合金中碳氮化物沿马氏体基体和晶界弥散析出,在强化基体金属提高硬度的同时能有效抵御冲蚀粒子的切削,增强抗冲蚀磨损性能,其磨损特征表现为冲蚀粒子冲击后留下的切削、犁沟以及碳氮化物处造成的块状剥离。     

Material Selection for Ceramic Gun Tube Liner

The U.S. Army Research Laboratory is investigating the application of ceramics as bore materials in advanced gun systems. The lower mass and improved high temperature performance of ceramics over traditional gun steels could produce new barrels with improved service life and lower weight while enabling the use of new propellants. Several different ceramics have been researched into which material would best survive the interior ballistic conditions for a variety of different caliber systems. The candidate materials are commercially available monolithic ceramics. Alumina, zirconia, three silicon carbide compositions, two silicon nitride compositions, and a SiAlON material were initially selected. A coupled approach of modeling and experimental verification led to the downselection of the silicon nitride and SiAlON materials as the most capable of surviving the interior ballistic conditions and functioning as a barrel liner. This paper describes the tests, presents the results, and discusses the reasons for these selections.     

Unique Features and Properties of Nanostructured Materials

In this introductory paper an attempt is made to give an overview of the area of nanostructured materials irrespective of the synthesis process. The various microstructural features such as clusters or isolated nanoparticles, agglomerated nanopowders, consolidated nanomaterials and nanocomposite materials as well as all materials classes are considered. As an important component of modern research on nanomaterials a section describes the various characterization tools available. Based on these remarks some properties of nanostructured materials will be summarized emphasizing the property–microstructure relationships. Finally, a brief outlook on applications and initial industrial use of nanomaterials is presented.     

NSF cyberinfrastructures: A new paradigm for advancing materials simulation

This paper discusses the motivation for the creation of cyberinfrastructures to enhance specific technical areas of research. It then goes on to provide a review of two cyberinfrastructures supported by the National Science Foundation, OpenKIM and CAMS, which are geared towards enhancing materials modeling at the atomic scale. Their objectives, accomplishments, and future goals are discussed. Lastly, the future outlook for cyberinfrastructures such as these to impact materials modeling is discussed.     

A prototype knowledge-based system for material selection of ceramic matrix composites of automotive engine components

A prototype knowledge based system (KBS) for material selection of ceramic matrix composites (CMC) for engine components such as piston, connecting rod and piston ring is proposed in this paper. The main aim of this research work is to select the most suitable material for the automotive engine components. The selection criteria are based upon the pre-defined constraint value. The constraint values are mechanical, physical properties and manufacturing techniques. The constraint values are the safety values for the product design. The constraint values are selected from the product design specification. The product design specification values are selected from the past design calculation and some values are calculated by the help of past design data. The knowledge-based system consists of several modules such as knowledge acquisition module, inference module and user interface module. The domains of the knowledge-based system are defined as objects and linked together by hierarchical graph. The system is capable of selecting the most suitable materials and ranks the materials with respect to their properties. The design engineers can choose the required materials related to the materials property.     

Systems design of hierarchically structured materials: Advanced steels

A systems approach integrates processing/structure/property/performance relations in the conceptual design of multilevel-structured materials. Using the example of high performance alloy steels, numerical implemen- tation of materials science principles provides a hierarchy of computational models defining subsystem design parameters which are integrated via computational thermodynamics in the comprehensive design of materials as interactive systems. Materials design class projects address application of the methods in metals, ceramics, and polymers for special applications.     

从生态环境角度浅析绿色环保包装材料的应用

随着生态文明发展的浪潮日渐兴起,人们越来越重视绿色环保的理念,近几年随着中国对环保意识的重视,绿色环保包装材料取得了一定的研究成果,并且在国内包装设计领域得到了普及和应用。以生态环境的角度,结合绿色材料选择的意义,分别对不同的环保包装材料进行探究,如纸包装材料、可降解包装材料、天然生物包装材料以及可食性包装材料。从而进一步深刻地理解绿色环保包装材料选择的必要性及有效性。     

A Review on Dissimilar Friction Stir Welding of Copper to Aluminum: Process,Properties, and Variants

Copper and aluminum materials are extensively used in different industries because of its great conductivities and corrosion resistant nature. It is important to join dissimilar materials such as copper and aluminum to permit maximum use of the special properties of both the materials. The joining of dissimilar materials is one of the most advanced topics, which researchers have found from last few years. Friction stir welding (FSW) technology is feasible to join dissimilar materials because of its solid state nature. Present article provides a comprehensive insight on dissimilar copper to aluminum materials joined by FSW technology. FSW parameters such as tool design, tool pin offset, rotational speed, welding speed, tool tilt angle, and position of workpiece material in fixture for dissimilar Cu–Al system are summarized in the present review article. Additionally, welding defects, microstructure, and intermetallic compound generation for Cu–Al FSW system have been also discussed in this article. Furthermore, the new developments and future scope of dissimilar Cu–Al FSW system have been addressed.     

Accelerating materials discovery using machine learning

The discovery of new materials is one of the driving forces to promote the development of modern society and technology innovation,the traditional materials research mainly depended on the trial-and-error method,which is time-consuming and laborious.Recently,machine learning (ML) methods have made great progress in the researches of materials science with the arrival of the big-data era,which gives a deep revolution in human society and advance science greatly.However,there exist few systematic generalization and summaries about the applications of ML methods in materials science.In this review,we first provide a brief account of the progress of researches on materials science with ML employed,the main ideas and basic procedures of this method are emphatically introduced.Then the algorithms of ML which were frequently used in the researches of materials science are classified and compared.Finally,the recent meaningful applications of ML in metal materials,battery materials,photovoltaic materials and metallic glass are reviewed.     

无机材料性能与电子构型关系的探讨

无机材料的某些性能不仅取决于化学组成,而更主要的是取决于结构,包括显微结构、晶体结构、以及电子构型。本文将探讨某些性能与电子构型间关系,为寻找新材料与发展材料科学提供依据。     

Properties,Benefits, and Application of Nanocrystalline Structures in Magnetic Materials

The magnetic properties of nanocrystalline hard magnetic and soft magnetic are summarized. When the grain size becomes of the order f the magnetic exchange length exchange coupling occurs. The different concepts of exchange coupling in these materials are discussed. Exchange coupling leads in isotropic hard magnetic materials to a remanence enhancement. Soft magnetic materials exhibit due to exchange coupling a lower coercivity, lower losses and consequently also improved properties.