方兴未艾的陶瓷增材制造

正陶瓷材料因具有高强度、耐高温、耐腐蚀及良好的绝缘性和生物相容性等特点,被广泛应用于机械、电子、航空航天、生物医疗等领域。随着具备力学、热学、光学、电学及生物特性的新型陶瓷的快速发展,制造高性能、复杂结构陶瓷零件的需求日益迫切,这对陶瓷成型方法提出了越来越高的要求。传统陶瓷成型方法,如干压、凝胶注模、等静压、流延等对模具依赖性强,部分复杂结构陶瓷甚至难以采用传统成型方法制造。因此,探索无需模具的高性能、复杂结构陶瓷零件的新型成型方法已成为陶瓷领域的研究热点。     

陶瓷材料与结构增材制造技术研究现状

增材制造技术在聚合物材料与结构、金属材料与结构制备中已经得到了大量应用。近年来,陶瓷材料与结构的增材制造技术得到了初步发展,受到了越来越多陶瓷工作者的关注。本文综述了目前几种常见的陶瓷材料与结构增材制造技术,并预测了未来陶瓷材料与结构增材制造技术发展的主要关注点,以期为陶瓷工作者提供关于增材制造技术一定的参考与思考。     

关于不同金属3D打印增材制造技术对比研究

随着现代化科学信息技术的不断发展,3D打印增材制造技术已经广泛的应用在社会的各个领域。本文将围绕金属3D打印增材制造技术的优势进行阐述,并详细的分析不同金属3D打印增材制造技术之间的对比,并逐步优化3D打印增材制造技术的力学性能,旨在提升不同金属3D打印增材制造技术水平。     

增材制造技术在火炸药成型中的研究进展

针对国内外火工品、炸药、发射药、推进剂增材制造技术,按照增材制造的技术特点和应用方向,综述了国内外增材制造技术在火炸药成型中的研究现状。概述了材料喷射成型(Material jetting)、材料挤出成型(Material extruding)、光聚合固化技术(Vat photopolymerization)的成型原理、工艺特点及在火炸药成型中的应用情况,介绍了各类增材制造技术中火炸药的物料特性,并对火炸药增材制造技术发展方向进行了预测。指出火炸药增材制造应按照火炸药的应用背景,对增材制造火炸药配方(即耗材)的能量特性、力学特性、能量释放特性及工艺适配性等进行系统研究,以满足不同应用背景的发展需求。附参考文献97篇。     

陶瓷增材制造(3D打印)技术研究进展

高性能陶瓷是现代技术发展和应用不可或缺的关键材料。常规的陶瓷制造技术难以满足对个性化、精细化、轻量化和复杂化的高端产品快速制造的需求。新兴的增材制造技术(3D打印)在高性能陶瓷的成型制造领域具有巨大的发展潜力,有望突破传统陶瓷加工和生产的技术瓶颈,为陶瓷关键零部件的应用开辟新的途径。本文针对陶瓷材料及其快速成型和后处理工艺,重点阐述了三维打印技术、光固化成型技术、选择性激光烧结技术等主流陶瓷增材制造技术的研究现状,并指出了目前存在的问题及发展趋势。     

基于挤出工艺的陶瓷零件增材制造及其关键技术

增材制造技术可以直接从CAD模型得到实体零件,无需加工刀具和模具,非常适合于结构复杂陶瓷零件的个性化、差异化制造。基于浆料或者膏体挤出而开发的陶瓷零件增材制造技术实用灵活,工艺方法也最多。本文主要阐述了基于挤出技术的增材制造技术的技术原理和特点,并对其中涉及的挤出材料、挤出方式和工艺控制等关键技术进行了综述。     

面向增材制造的废弃陶瓷再生技术的研究

研究了一种面向增材制造的废弃陶瓷再生技术,将废瓷再生处理成新的陶瓷制品.首先将粘合剂、增塑剂等均匀混合后分散到去离子水中得到粘结剂体系;废弃陶瓷进行球磨、过筛等处理后获得废瓷粉料,将其加入粘结剂体系中制备高固相含量和较好流动性的陶瓷膏体;通过实验确定合适的3D打印工艺参数并利用浆料挤出成型式打印机(型号:SP-FP450)打印出坯体,经热处理得到再生陶瓷制品.本作品创新性地将废弃陶瓷再生利用与增材制造技术相结合,能够解决废瓷带来的资源浪费和土地资源占用,符合绿色制造和先进制造发展方向.     

电沉积3D打印增材制造原理与实现方法简述

随着科技的进步和经济的迅速发展,3D打印技术逐渐走进人们的生活,电沉积3D打印技术在微器件的加工制造方面得到了广泛关注。本文,首先从电沉积原理出发,结合赫尔槽试验现象,系统论述了不均匀沉积发生的试验现象和根本原因;其后,从“电沉积反应的临界点”的方面阐述了电沉积3D打印的实现原理;最后对现有关于电沉积3D打印技术的研究进行了简述。本文对定域性电沉积和电沉积3D打印相关理论的阐述及研究总结,将为定域性电沉积和电沉积3D打印技术的发展提供较好的指导作用。     

基于浆料的陶瓷增材制造技术制备多孔陶瓷研究进展

多孔陶瓷因将多孔结构引入到陶瓷材料中而具备体积密度低、比表面积高、导热系数低、耐高温、耐腐蚀等特点,在催化过滤、生物支架、保温隔热、轻质结构部件等方面具有广泛的应用。多级孔陶瓷有效整合了多种孔结构带来的性能优势,实现了材料在同等体积水平的功能最大化,成为多孔陶瓷的发展趋势,然而其制备仍存在巨大挑战。陶瓷增材制造技术突破了传统陶瓷成形工艺需要特定模具且成形精度低的限制,仅通过层层连接的方式即可成形各种复杂形状、高精度陶瓷材料。打印前原材料形式包括粉体、块材、线材和浆料,其中基于浆料的陶瓷增材制造技术结合了陶瓷增材制造技术及胶态成形工艺的优势,不仅有利于复杂组分之间均匀混合,还为构建亚微米甚至纳米级别孔结构,实现复杂形状、精细结构多级孔陶瓷的制备提供了条件。首先概述了5类以浆料形式进行打印的陶瓷增材制造技术,包括立体光固化技术、数字光处理技术、双光子聚合技术、喷墨印刷技术以及浆料直写成形技术。进一步系统分析了基于浆料的陶瓷增材制造技术与现有多孔陶瓷制备工艺结合制备多级孔陶瓷的研究现状。最后,对基于浆料的陶瓷增材制造技术制得多孔陶瓷的具体应用及发展方向进行了分析与展望。     

Additive manufacturing of ceramics: Advances,challenges, and outlook

Additive manufacturing (AM) of ceramics is relatively more challenging with respect to polymers and metals, owing to their high melting temperatures and inherent brittleness. Thus, this review aims to provide a comprehensive survey of recent AM technologies successfully employed to produce net shape ceramic components. In recent years, several techniques have been developed and the latest progress in this field are highlighted, as well as the current challenges in the complex shaped ceramic parts production via AM technologies. The state of the art concerning the various 3D printing processes applied to the fabrication of ceramic components is discussed with, for each method, the presentation of its advantages, disadvantages, and possible applications. The potential of AM for producing complex shape ceramic components and the challenges to overcome are discussed as well.     

Additive Manufacturing in Fluid Process Engineering

Additive manufacturing describes technologies that translate virtual computer‐aided design data into physical models in a fast process. While industries such as automotive and aerospace adopt this manufacturing technique rapidly, it is little applied within process engineering. Additive manufacturing offers freedom of design which gives access to novel shapes and geometries with fast production times. This review analyses the most important layer fabrication principles first and shows applications of additive manufacturing in fluid process engineering second. The review focuses on applications where liquids and gases are involved and it showcases the potential of additive manufacturing within process engineering of functional devices. Examples of current research projects show the potential of the technology for advances process engineering.     

Additive manufacturing of electrofused mullite slurry by digital light processing

Mullite, one of the main refractory materials, has several applications that may demand tiny structures with complex geometries, and digital light processing (DLP) can produce such parts with outstanding dimensional precision and surface quality. In this work, electrofused mullite powder was used as a raw material for additive manufacturing by DLP. Photosensitive mullite suspensions were developed and their rheological behavior, stability, and thermal decomposition were investigated. Mullite parts were printed from suspensions with different ceramic loadings, debound, and sintered at different temperatures (from 1500 to 1650 °C). Density and strength increased with an increase in both solid loading and sintering temperature. Printed parts from slurry with 50 vol% of solid loading sintered at 1650 °C reached a relative density of 97.7 ± 0.3 % and flexural strength of 95.2 ± 5.0 MPa.     

Polypropylene/Cellulose Composites for Material Extrusion Additive Manufacturing

The preparation of polypropylene (PP)/microcrystalline cellulose (MCC) composites and their applicability for material extrusion additive manufacturing (ME‐AM) is reported. MCC is modified by grafting onto its surface with different silanes, in particular perfluorooctyltriethoxysilane, n‐octyltriethoxysilane (OTS), or aminopropyltriethoxysilane. The efficacy of the surface modification is confirmed by attenuated total reflectance and X‐ray photoelectron spectroscopy. The affinity of the modified MCC to the polar PP matrix is investigated by direct melt‐compounding, and the applicability of the resulting composites for material ME‐AM is accessed by fabrication of filaments and evaluating the relevant property requirements. The surface modification of the MCC improves their dispersibility in PP and enhances the mechanical properties of the composites. Moreover, the OTS‐modified MCC shows the best reinforcement, good surface finish of the filament, and flawless printability.     

3D printing of fine alumina powders by binder jetting

Additive manufacturing of ceramics is still at an early-development stage; however, the huge interest in custom production of these materials has led to the development of different techniques that could provide highly performing devices. In this work, alumina (α-Al₂O₃) components were produced by binder jetting 3D printing (BJ), a powder-based technique that enables the ex-situ thermal treatment of the printed parts. The employment of fine particles has led to high green relative density values (>60 %), as predicted by Lubachevsky-Stillinger algorithm and DEM modelling. Then, extended sintering has been observed on samples treated at 1750 °C that have reached a final density of 75.4 %. Finally, the mechanical properties of the sintered material have been assessed through bending test for flexural resistance and micro-indentation for Vickers hardness evaluation.     

Additive manufacturing of SiSiC by layerwise slurry deposition and binder jetting (LSD-print)

The current work presents for the first time results on the Additive Manufacturing of SiSiC complex parts based on the Layerwise Slurry Deposition (LSD) process. This technology allows to deposit highly packed powder layers by spreading a ceramic slurry and drying. The capillary forces acting during the process are responsible for the dense powder packing and the good joining between layers. The LSD process can be combined with binder jetting to print 2D cross-sections of an object in each successive layer, thus forming a 3D part. This process is named LSD-print.By LSD-print and silicon infiltration, SiSiC parts with complex geometries and features down to 1 mm and an aspect ratio up to 4:1 could be demonstrated.The density and morphology were investigated for a large number of samples. Furthermore, the density and the mechanical properties, measured by ball-on-three-balls method, were in all three building directions close to isostatic pressed references.     

3D打印在弹性体领域的应用

以弹性体为打印材料的3D打印技术为熔融沉积快速成型、立体光固化、选择性激光烧结和聚合物喷射。简介热塑性弹性体打印材料和热固性弹性体打印材料,概述3D打印技术在弹性体制品生产中的应用,综述3D打印技术在弹性体领域的发展和挑战。光硫化或光固化是橡胶领域3D打印技术的发展趋势。     

Additive manufacturing of barium titanate based ceramic heaters with positive temperature coefficient of resistance (PTCR)

Lanthanum/manganese doped barium titanate (BT) based PTCR functional heater elements/structures were fabricated with desirable electrical properties for the first time using Additive Manufacturing (AM). 3D printed components of varying size and shape and prototype honeycomb lattices with high density were achieved through AM. Aqueous, less organic containing (2.5 wt% additives versus 10–30 wt% added typically), eco-friendly ink formulations were developed with suitable rheological properties for 3D printing. For BT prints, the sintered densities of the 3D ceramic parts were found to be >99% TD, highest reported value so far. The microstructure, electrical properties and heating characteristics of the printed PTCR components were studied in detail and their thermal stability evaluated using infrared imaging and benchmarked against commercial PTCR heating element. The heating behaviour of the solid and porous 3D printed components was demonstrated to be similar, paving the way for light weight (?47% reduction in weight) heaters suitable for automotive/aerospace applications and less materials wastage during device fabrication.