Powder bed binder jet 3D printing of Inconel 718: Densification,microstructural evolution and challenges☆

Traditional manufacturing of Inconel 718 components from castings and thermomechanical processing routes involve extensive post processing and machining to attain the desired geometry. Additive manufacturing (AM) technologies including direct energy deposition (DED), selective laser melting (SLM), electron beam melting (EBM) and binder jet 3D printing (BJ3DP) can minimize scrap generation and reduce lead times. While there is extensive literature on the use of melting and solidification based AM technologies, there has been limited research on the use of binder jet 3D printing. In this paper, a brief review on binder jet additive manufacturing of Inconel 718 is presented. In addition, existing knowledge on sintering of Inconel 718 has been extended to binder jet 3D printing. We found that supersolidus liquid phase sintering (SLPS) is necessary to achieve full densification of Inconel 718. SLPS is sensitive to the feedstock chemistry that has a strong influence on the liquid volume fraction at the processing temperature. Based on these results, we discuss an empirical framework to determine the role of powder particle size and liquid volume fraction on sintering kinetics. The role of powder packing factor and binder saturation on microstructural evolution is discussed. The current challenges in the use of BJ3DP for fabrication of Inconel 718, as well as, extension to other metal systems, are presented.     

3D视像和3D音像

我们日常生活的空间是一个三维（3D,threedimensional）世界,人们是用两只眼睛观察周围具有空间立体感的外界景物的,即具有长、宽、高三种度量,因此以3D的形式展现我们所看、所听的世界是与生俱来的所见皆是。但是由于种种原因,人们以前对音、像的再现都是二维的,随着人类科技的发展,3D是未来发展的必然趋势,而这些都是源于人们不断地进取与追求。     

2D and 3D orientation mapping in nanostructured metals: A review

Nanostructured metals possess various excellent properties and offer the potential for a wide range of applications.Improvements in the properties and performance of nanostructured metal components motivate a complete characterization of the microstructures and crystallographic orientations of nanostructured metals with nanoscale spatial resolution.Two well developed orientation mapping techniques for such characterization are electron backscatter diffraction(EBSD)in the scanning electron microscope and precession electron diffraction(PED)using diffraction spots in the transmission electron microscope.However,these methods can only characterize the structure in two dimensions.It is still a great challenge to characterize grains in three dimensions,i.e.from the interior of the nanostructured metals.Recently,three-dimensional orientation mapping in the transmission electron microscope(3 D-OMi TEM)was developed and further improvements of this technique are introduced in this paper.Utilization of these orientation mapping techniques for structural and orientational characterizations are demonstrated by examples of surface-deformed metals with gradient nanostructures,and a sputtered gold film of nano-islands containing nanograins.The merits and challenges of each of these techniques are discussed and suggestions for further developments are proposed.     

首款3D投影机PJD 6210-3D

从VCD到DVD，从标清到高清，视频影像逐步发展到现在的高清蓝光时代，分辨率的提升、显示尺寸的增加，给我们带来全新的视觉感受。然而，视频从2D到3D的进化，又将掀起了新一轮影像革命。日前，国内知名显示设备厂商优派将3D技术引入液晶显示器与投影机之中，在率先推出国内首款3D显示器之后，又推出一款3D投影机PJD6210—3D。     

Topological evolutionary computing in the optimal design of 2D and 3D structures†

An application of evolutionary algorithms and the finite-element method to the topology optimization of 2D structures (plane stress, bending plates, and shells) and 3D structures is described. The basis of the topological evolutionary optimization is the direct control of the density material distribution (or thickness for 2D structures) by the evolutionary algorithm. The structures are optimized for stress, mass, and compliance criteria. The numerical examples demonstrate that this method is an effective technique for solving problems in computer-aided optimal design.     

全球最大3D打印零售店3D Printhuset面世

正3D Printhuset是世界上最大的3D打印零售店,位于丹麦哥本哈根。近日,其开设了一家全新的、更大的零售店。值得一提的是,这间商店横跨6000平方英尺,是栋三层楼的联排别墅,较之前的最大3D打印零售店相比,规模扩大了两倍。两年前,3D Printhuset在哥本哈根开设了"最大的3D打印零售店",3000平方英     

3D Flash Display for STL Model in Rapid Prototyping System

A kind of 3D color graphics display system for the STL model is developed by calling the functions from Open GL graphic library through VC 6. 0 under the Windows environment in this paper. The STL model is a high quality one that can be quiescent or animated. This system is conducive to find out the disfigurement of the STL model in a rapid prototyping process and to repair it, Therefore, the component quality can be enhanced.     

3D printing of Al<Subscript>2</Subscript>O<Subscript>3</Subscript>/Cu–O interpenetrating phase composite

Porous alumina preforms were fabricated by indirect 3D printing using a blend of alumina and dextrin as a precursor material. The bimodal granulate powder distribution with a bed density of 0.8 g/cm³ was increased to 1.4 g/cm³ by overprinting. The porosity of the sintered bodies was controlled by adjusting the printing liquid to precursor powder ratio in the range of 33–44 vol%. The green bodies exhibited bending strengths between 4 and 55 MPa. An isotropic linear shrinkage of ~17% was obtained due to dextrin decomposition and Al₂O₃ sintering at 1600 °C. Post-pressureless infiltration of the sintered preforms with a Cu–O alloy at 1300 °C for 1.5 h led to the formation of a dense Al₂O₃/Cu–O interpenetrating phase composite (IPC). X-ray analysis of the fabricated composites showed the presence of α-Al₂O₃, Cu and Cu₂O. CuAl₂O₄ spinel was not observed at the grain boundaries during HRTEM examination. The Al₂O₃/Cu–O interpenetrating phase composite revealed a fracture toughness of 5.5 ± 0.3 MPam^1/2 and a bending strength of 236 ± 32 MPa. In order to demonstrate technological capability of this approach, complex-shaped bodies were fabricated.     

松下发布3D相机DMC－3D1

近日。松下发布了双镜头4x光学变焦便携数码相机LumixDMC－3D1。3D1搭载1200万像素“高感光度CMOS”传感器，VenusEngine影像处理引擎，支持拍摄2D及3D照片。拥有3．5英寸的触摸屏。连拍速度8fPs。双镜头可以独立进行对焦与变焦。     

D3S 技术

D3S技术是在系列图像分析基础上发展形成的多学科的边缘前沿技术，已经广泛地应用于气象观测、作物识别、医疗诊断、自动化和机器人导航等领域，近年又在目标识别、参数测量、寻的跟踪、交会对接和三维高觉等高技术应用领域取得了很多突破性的研究成果，并在地质数据分析和侦察等方面显示出重要应用前景。本文分析总结了D3S技术近10年来的发展趋势和特点。     

浅析3D打印

在电影《十二生肖》里,成龙双手白手套掠过兽首,就把头像的数据扫描进电脑。与此同时,他的伙伴在一台神奇的机器里,瞬间就把一模一样的兽首制造出来。其运用的就是当今最热门的三维数字化与 3D 打印技术。如果你想要一件工具,将计算机设计出的三维模型分解成若干层平面切片,然后把打印材料按切片图形逐层叠加,最终堆积成完整的物体 , 几小时后你就能使用这件工具了。小到食品、大到航空产品都能够"打印"出来。     

3D打印产业

<正>民革中央提交了"关于大力支持3D打印技术创新和产业发展"的提案,从技术、市场等4个方面提出了发展意见。其中,特别强调要前瞻布局关键核心技术,重点推进3D打印装备的产业化。目前,我国3D打印技术虽然取得了长足进展,与美欧等发达国家基本处于同一水平,甚至在金属构件打印方面已经超过美国。但产业整体发展仍处于起步阶段。民革中央提出,与美国大力支持3D打印技术发展和产业发展相比,我国对这项技术总体规划与重视不够。为加快推进我国3D打印技术创新和产业发展,民革中央提出以下建议:增强自主创新能力,加强技术平台建设。建立以市场需求为导向,研究机构、民革中央:重点推进3D打印装备产业化     

解密3D打印

在前面我们报道了"全国首家 3D 打印体验馆落户DRC 基地",那么究竟什么是 3D 打印? 3D 打印能做什么?设计和 3D 打印有什么关系?本刊记者再次探访 3D打印应用推广的先行者——位于 DRC 北京工业设计创意产业基地的北京上拓科技有限公司,并结合案例详细介绍下这几个用户最为关心的问题。     

3D打印气管

2011年，卡伊巴（Kaiba）还只有6个星期大时．他突然停止了呼吸，脸色发青。他的父母赶紧把他送到了医院，医生很遗憾地发现他的左丁气管有先天性缺陷。此后，病情反复发作，直到2012年的一月，外科医生们在他的肺部植入了一个3D打印的气管，才使他的呼吸遁保持畅通。几年之后，这个人造气管会在体内自行溶解，     

3D元年到来

从2009年初3D显示器上市，到2010年3D投影机的普及推广，业内习惯把去年或今年称之为“3D元年”。而《阿凡达》等3D大片的热映，也加深了“30元年”的份量。《阿凡达》的热映让不少观众生平第一次感受到3D的惊人魅力。那么，究竟3D显示技术是如何让我们感受到3D震撼的临场效果呢？     

“3D博览会”聚焦3D技术应用之路

2011中国3D技术与创意博览会在朝阳规划艺术馆开幕。作为第六届北京文博会的亮点活动,今年主题为"体验3D技术、促进创意经济",期间,2010上海世博会3D纪录片、2010广州亚     

3D打印气管

2011年，卡伊巴（Kaiba）还只有6个星期大时，他突然停止了呼吸．脸色发青。他的父母赶紧把他送到了医院，医生很遗憾地发现他的左支气管有先天性缺陷。此后，病情反复发作，直到2012年的一月，外科医生们在他的肺部植入了一个3D打印的气管，才使他的呼吸道保持畅通。     

3D打印革命

从上世纪80年代问世以来,5D打印技术已经不是什么新鲜的概念,却依然没有大规模的应用。高昂的成本、不易操作的参数输入方式、不太稳定的打印制造效果……种种的限制都让利用这项技术进行批量生产的难度加大。     

三光路3D和双光路3D综合对比

正随着影院3D技术的发展,主动式快门3D技术和杜比色轮3D技术已经基本退出市场。目前在市场上广泛应用的主要有两类3D技术:偏振式3D技术、基于6色激光技术的6P激光3D技术。其中偏     

浅谈3D服装设计

人类社会发展到今天,服装制作技术经历了手工制作、机器加工、电脑辅助二维服装设计几个过程。进入新时代,服装设计有了新的生命力,开始了由二维向三维设计的过度。本文从国外3D服装设计入手,比较国内服装设计的趋势,阐述了3D服装设计的发展方向和运用前景,更对以后的院校3D服装教育研究做了详细的说明,最后对新技术引起的产业升级在就业上的变化做了预测。