Additive Manufacturing of Nickel-Base Superalloy IN100 Through Scanning Laser Epitaxy

Scanning laser epitaxy (SLE) is a laser powder bed fusion (LPBF)-based additive manufacturing process that uses a high-power laser to consolidate metal powders facilitating the fabrication of three-dimensional objects. In the present study, SLE is used to produce samples of IN100, a high-γ′ non-weldable nickel-base superalloy on similar chemistry substrates. A thorough analysis is performed using various advanced material characterization techniques such as high-resolution optical microscopy, scanning electron microscopy, energy dispersive x-ray spectroscopy, and Vickers microhardness measurements to characterize and compare the quality of the SLE-fabricated IN100 deposits with the investment cast IN100 substrates. The results show that the IN100 deposits have a finer γ/γ′ microstructure, weaker elemental segregation, and higher microhardness compared with the substrate. Through this study, it is demonstrated that the SLE process has tremendous potential in the repair and manufacture of gas turbine hot-section components.     

西马克增材制造技术研究

西马克集团增材制造研发中心,将增材制造产业的整个价值链作为研究方向,其研发制造的雾化粉末设备,可以生产高品质的金属粉末,具有成本低、效率高的优势。该设备集成了卫星粉防控技术,极大地降低了不合格粉末颗粒的含量,同时,通过对雾化过程进行CFD计算流体动力学仿真(以下简称CFD仿真),优化了紧耦合喷嘴的设计,提高了金属粉末的性能和收得率。     

增材制造技术的发展

增材制造技术是近30年快速发展的特种加工技术,其优势在于三维结构的快速和自由制造,被广泛应用于新产品开发、单件小批量制造。通过对增材制造技术设备和应用情况的介绍,阐述了我国增材制造技术的发展趋势和关键技术。未来增材制造技术将向着三个方向发展:一是日常消费品制造方向;二是功能零件制造方向;三是组织与结构一体化制造方向。     

Metal Additive Manufacturing: A Review

This paper reviews the state-of-the-art of an important, rapidly emerging, manufacturing technology that is alternatively called additive manufacturing (AM), direct digital manufacturing, free form fabrication, or 3D printing, etc. A broad contextual overview of metallic AM is provided. AM has the potential to revolutionize the global parts manufacturing and logistics landscape. It enables distributed manufacturing and the productions of parts-on-demand while offering the potential to reduce cost, energy consumption, and carbon footprint. This paper explores the material science, processes, and business consideration associated with achieving these performance gains. It is concluded that a paradigm shift is required in order to fully exploit AM potential.     

锥形喷嘴水射流反推力的研究

认识并掌握水射流产生推进力的机理,是进行水射流切削系统和水射流推进系统设计的基础.本文对几种不同出口直径和锥角的锥形喷嘴水射流反推力进行了理论分析和仿真计算,研究了压力、流量和锥形喷嘴的结构参数对反推力及反推力系数的影响,从而确定锥形喷嘴的最佳结构参数.     

Additive Manufacturing of Composites and Complex Materials

Advanced composite materials form an important class of high-performance industrial materials used in weight-sensitive applications such as aerospace structures, automotive structures and sports equipment. In many of these applications, parts are made in small production runs, are highly customized and involve long process development times. Developments in additive manufacturing (AM) methods have helped in overcoming many of these limitations. The special topic of Additive Manufacturing of Composites and Complex Materials captures the state of the art in this area by collecting nine papers that present much novel advancement in this field. The studies under this topic show advancement in the area of AM of carbon fiber and graphene-reinforced composites with high thermal and electrical conductivities, development of new hollow glass particle-filled syntactic foam filaments for printing lightweight structures and integration of sensors or actuators during AM of metallic parts. Some of the studies are focused on process optimization or modification to increase the manufacturing speed or tuning manufacturing techniques to enable AM of new materials.     

An Overview on Additive Manufacturing of Polymers

We present an overview on additive manufacturing (AM), also called three-dimensional printing, with a focus on polymers. First, we introduce the AM concept. Next, we outline several AM processes, including their advantages and limitations, and list common polymers that are used in commercial printers. Then, we state various AM applications and present two examples. We conclude with a global view of the AM field, its challenges, and future directions.     

Additive Manufacturing: Making Imagination the Major Limitation

Additive manufacturing (AM) refers to an advanced technology used for the fabrication of three-dimensional near-net-shaped functional components directly from computer models, using unit materials. The fundamentals and working principle of AM offer several advantages, including near-net-shape capabilities, superior design and geometrical flexibility, innovative multi-material fabrication, reduced tooling and fixturing, shorter cycle time for design and manufacturing, instant local production at a global scale, and material, energy, and cost efficiency. Well suiting the requests of modern manufacturing climate, AM is viewed as the new industrial revolution, making its way into a continuously increasing number of industries, such as aerospace, defense, automotive, medical, architecture, art, jewelry, and food. This overview was created to relate the historical evolution of the AM technology to its state-of-the-art developments and emerging applications. Generic thoughts on the microstructural characteristics, properties, and performance of AM-fabricated materials will also be discussed, primarily related to metallic materials. This write-up will introduce the general reader to specifics of the AM field vis-à-vis advantages and common techniques, materials and properties, current applications, and future opportunities.     

Strategy for Texture Management in Metals Additive Manufacturing

Additive manufacturing (AM) technologies have long been recognized for their ability to fabricate complex geometric components directly from models conceptualized through computers, allowing for complicated designs and assemblies to be fabricated at lower costs, with shorter time to market, and improved function. Lacking behind the design complexity aspect is the ability to fully exploit AM processes for control over texture within AM components. Currently, standard heat-fill strategies utilized in AM processes result in largely columnar grain structures. Proposed in this work is a point heat source fill for the electron beam melting (EBM) process through which the texture in AM materials can be controlled. Through this point heat source strategy, the ability to form either columnar or equiaxed grain structures upon solidification through changes in the process parameters associated with the point heat source fill is demonstrated for the nickel-base superalloy, Inconel 718. Mechanically, the material is demonstrated to exhibit either anisotropic properties for the columnar-grained material fabricated through using the standard raster scan of the EBM process or isotropic properties for the equiaxed material fabricated using the point heat source fill.     

Five-Axis Ultrasonic Additive Manufacturing for Nuclear Component Manufacture

Ultrasonic additive manufacturing (UAM) is a three-dimensional metal printing technology which uses high-frequency vibrations to scrub and weld together both similar and dissimilar metal foils. There is no melting in the process and no special atmosphere requirements are needed. Consequently, dissimilar metals can be joined with little to no intermetallic compound formation, and large components can be manufactured. These attributes have the potential to transform manufacturing of nuclear reactor core components such as control elements for the High Flux Isotope Reactor at Oak Ridge National Laboratory. These components are hybrid structures consisting of an outer cladding layer in contact with the coolant with neutron-absorbing materials inside, such as neutron poisons for reactor control purposes. UAM systems are built into a computer numerical control (CNC) framework to utilize intermittent subtractive processes. These subtractive processes are used to introduce internal features as the component is being built and for net shaping. The CNC framework is also used for controlling the motion of the welding operation. It is demonstrated here that curved components with embedded features can be produced using a five-axis code for the welder for the first time.     

激光增材制造技术在铸造中的应用

增材制造技术实现了从三维模型数据直接成型实体零件的过程,具有周期短、精度高、零件复杂性的特点。将增材制造技术与铸造相结合,可提高铸件的生产效率、降低成本,扩大铸造工艺的应用领域及发展方向。简介了增材制造的工艺流程及成型原理,并分别阐述了增材制造技术在熔模精密铸造和砂型铸造工艺中的具体流程及实际应用。     

Additive Manufacturing of Metallic Materials: A Review

In this review article, the latest developments of the four most common additive manufacturing methods for metallic materials are reviewed, including powder bed fusion, direct energy deposition, binder jetting, and sheet lamination. In addition to the process principles, the microstructures and mechanical properties of AM-fabricated parts are comprehensively compared and evaluated. Finally, several future research directions are suggested.     

增材制造技术在铸造中的应用

增材制造技术在铸造中的应用是增材制造技术应用的主要领域之一.它可在无模具条件下直接制备铸造型(芯)、快速浇注复杂铸件.将增材制造与传统铸造技术相结合,打破了传统铸造工艺束缚,提高了铸造柔性,改善了铸造环境;可实现零件"自由铸造",极大减少加工工序,缩短制造周期.本文概述了增材制造技术的基本原理及其国内外发展概况,重点介...     

增材制造机床产品标准体系的构建

通过对增材制造产业发展概况、国内增材制造机床产品标准现状的介绍,初步建立了增材制造机床产品标准体系框图,为今后开展增材制造机床产品标准的制修订和相关标准化工作提供依据。     

多材料增材制造研究现状及展望

随着高端装备对构件性能要求的不断提升,比如一个构件的不同位置需分别实现高强度、高韧性、高导热、耐腐蚀,增材制造亟需从单一材料结构向多材料结构突破,面向构件性能最优的多材料增材制造也成为研究热点.按增材制造材料大类划分,分别概述了聚合物、金属和陶瓷多材料增材制造技术原理、成形系统构建与优化、材料结合界面宏微观特性;介绍了...