熔融沉积成型3D打印技术应用进展及展望

介绍熔融沉积制造(FDM)3D打印技术的产生和特点。着重介绍了FDM 3D打印技术在汽车工业、航空航天、医疗卫生、教育教学、食品加工等领域的实际应用情况。并对FDM 3D打印技术的应用前景进行展望。     

熔融沉积法3D打印制备多孔氧化锆陶瓷

以氧化锆粉为主要原料,采用基于螺杆挤出的熔融沉积法在4种打印路径(单线、网格、单线+矩形、网格+矩形)下3D打印制备了孔隙率均分别为15%、25%、35%、45%的多孔氧化锆陶瓷。对多孔陶瓷的孔壁、打印层间结合、孔结构等进行了显微结构分析,并检测压缩强度。结果表明：1)采用熔融沉积法可以3D打印制备孔壁结构致密、孔形状保持良好的多孔陶瓷;2)低孔隙率时,多孔氧化锆陶瓷的应力-应变曲线呈弹性阶段,无坍塌阶段,随着孔隙率升高,出现明显的坍塌阶段;3)在相同孔隙率下,混合路径制备的多孔陶瓷的压缩强度比单一路径的更高,当孔隙率为15%时,单线+矩形路径打印的多孔陶瓷的压缩强度最高,达到271 MPa。     

填充结构对熔融沉积3D打印制件拉伸性能的影响

为提高熔融沉积3D打印制件的拉伸性能,通过熔融沉积3D打印工艺制作哑铃型试样,探究填充结构对3D打印制件拉伸性能的影响。结果表明,根据平面线型及空间特征,熔融沉积3D打印制件的填充结构分为三类：平行线型填充、立体单元型填充和网格线型填充;其中,平行线型填充结构中与拉伸方向一致的填充线条(丝材本体)数量影响了3D打印制件的拉伸性能,填充线条数量越多,制件的强度和刚度越大;立体单元型填充结构中的立体单元数量影响了3D打印制件的拉伸性能,立体单元的数量越多,制件的强度和刚度越大;网格线型填充结构中的网格密度影响了3D打印制件的拉伸性能,网格密度越大,制件的强度和刚度越大;相同工艺参数条件下,平行线型填充结构的比强度和比刚度最大,拉伸性能最强,立体单元型填充结构的拉伸性能次之,网格线型填充结构的拉伸性能最弱。     

熔融沉积3D打印工艺参数对圆弧制件轮廓精度的影响

采用正交试验设计,进行了圆弧弦长、成型角度、打印层厚、填充密度及打印速比五个工艺参数对熔融沉积3D打印圆弧制件轮廓精度的测试和结果分析,确定了轮廓精度影响程度由强到弱依次为:打印层厚＞圆弧弦长＞打印速比＞成型角度＞填充密度,其中打印层厚影响水平显著.在试验范围内,圆弧弦长8 mm,成型角度60°,打印层厚0.1 mm,...     

连续纤维增强热塑性复合材料3D打印的研究进展

结合连续纤维增强热塑性复合材料(CFRTPCs)熔融沉积成型(FDM)工艺的最新发展情况,将该工艺按照原材料初始状态划分为在线预浸与离线预浸两类,并分别介绍各自使用的材料要求及关键打印设备的运行原理;同时综述了CFRTPCs的FDM工艺改进与应用结构及潜在的应用领域。同时针对CFRTPCs打印产品力学性能低的缺点,对包括工艺固有属性、材料种类等方面的原因进行了分析。最后,提出了目前面临的问题,为CFRTPCs的3D打印技术进一步发展提供新思路。     

3D打印领域FDM专利申请现状浅析

熔融沉积成型缩写为FDM成型,属于3D打印领域一个重要分支,本文从全球专利申请总体趋势、地域分布、申请人排名、中国专利申请等各个方面分析了目前该领域专利状态,反映出FDM在全球具有较大的发展潜力。     

玻璃3D打印技术研究进展

3D打印是一种以数字模型文件为基础,运用计算机辅助逐层打印的方式构造三维物体的技术,近年来受到国内外的普遍关注,发展迅猛.介绍了3D打印玻璃技术的发展现状,内容包括熔融沉积、选择性激光烧结、立体光刻、数字光处理、墨水直写等玻璃3D打印技术,总结玻璃3D打印技术在各方面的应用,分析玻璃3D打印技术目前存在的问题,最后对玻...     

打印方式对熔融沉积成型制品性能的影响

通过挤出成型制备了可用于熔融沉积成型(FDM)的聚乳酸(PLA)/麦秸粉复合线材,然后打印成标准测试样条。研究了填充密度、层厚、打印速度、温度对3D打印制品的密度、打印时间、弯曲强度、弯曲模量、冲击强度以及动态力学性能的影响。结果表明:当打印制品的填充密度从20%提高到100%时,可以获得更高的力学性能和模量,弯曲强度、弯曲模量、冲击强度、储能模量分别提高了88.46%、44.20%、75.93%、43.39%,打印时间则延长了50.82%;当层厚从0.2 mm增加到0.7 mm时,制品的弯曲强度、弯曲模量、冲击强度分别下降了42.01%、39.94%、44.27%,但打印时间缩短了70.65%;当打印速度从20 mm/s提高到60 mm/s时,制品的弯曲强度、弯曲模量、冲击强度分别下降了33.52%、39.71%、37.14%,但打印时间缩短了43.75%;此外,温度的升高有利于制品层间的结合,当温度从190℃升至240℃时,制品的弯曲强度、弯曲模量、冲击强度分别提高了55.82%、33.33%、25.08%,但对打印时间没有影响。     

3D打印技术制备固体推进剂研究进展

概述了现有固体推进剂成型工艺,指出了3D打印固体推进剂的特点,综述了含能材料3D打印的应用研究现状,重点介绍了适于固体推进剂3D打印成型的材料与工艺,针对固体推进剂3D打印成型存在的困难,提出了可能的解决方法,认为3D打印技术制备复杂结构固体推进剂药柱是一个发展方向。     

有机硅3D打印的研究进展

有机硅材料具有良好的生物相容性、化学稳定性和力学性能等,在生物医用、包装与交通运输等方面应用广泛。传统工艺生产有机硅制品时间长、成本高,而且无法做到个性化生产。有机硅的3D打印是用3D打印技术加工成型有机硅材料制品,它能够实现有机硅产品的快速、个性化生产。介绍了直接有机硅3D打印中光固化3D打印与基于挤出的3D打印2种技术在材料、打印工艺方面的研究进展。     

基于3D打印技术制造柔性传感器研究进展

与传统的涂覆、沉积等加工手段相比,使用3D打印技术可制造复杂立体功能结构的传感器,将3D打印与柔性传感技术结合可以促进未来生物医疗、人工智能等领域的发展。本文介绍了国内外基于3D打印技术制造柔性传感器的最新进展,其中包括聚酰亚胺等多种基底材料、纳米金属等多种打印传感材料;按照熔融沉积、黏弹性墨水沉积、粉末烧结熔化、还原光聚合和材料喷射的制造原理分别阐述了多种传感器的材料选择、成型特点,并对制造方法进行总结分析。虽然3D打印制造柔性传感器件存在着缺乏行业标准及多种类打印材料等问题,但经过不断创新与发展,3D打印将成为柔性传感领域极佳的制造手段。     

3D printing of porcelain by layerwise slurry deposition

The Layerwise Slurry Deposition is a technology for the deposition of highly packed powder layers. A powder bed is achieved by depositing and drying layers of a ceramic suspension by means of a doctor blade. This deposition technique was combined with the binder jetting technology to develop a novel Additive Manufacturing technology, named LSD-print. The LSD-print was applied to a porcelain ceramic. It is shown that it was possible to produce parts with high definition, good surface finish and at the same time having physical and mechanical properties close to those of traditionally processed porcelain, e.g. by slip casting.This technology shows high future potential for being integrated alongside traditional production of porcelain, as it is easily scalable to large areas while maintaining a good definition. Both the Layerwise Slurry Deposition method and the binder jetting technologies are readily scalable to areas as large as >1?m².     

Optimized preceramic polymer for 3D structured ceramics via fused deposition modeling

3D structured ceramics stemmed from preceramic polymers via additive manufacturing have attracted much attention recently. However, these polymers with high ceramic yield are so brittle that extrusion-based additive manufacturing techniques are hardly able to be utilized for assembling 3D structures. Herein, we developed a strategy to prepare feedstocks for these manufacturing techniques, i.e., utilizing a small amount of thermal-plastic polymer to optimize the preceramic polymer while good compatibility is required between the two polymers to ensure a homogeneous mixture. Polycarbosilane and polypropylene were selected as the representative materials. Polypropylene occupied a small proportion (≤5wt.%) and significantly improved the formability of the precursor. Three-dimensional SiC were obtained via fused deposition modeling combined with crosslinking and pyrolysis. The SiC ceramic filaments showed a mean tensile strength of 471 MPa. The strategy is also applicable to a large field of ceramic systems with corresponding precursor, such as sialon ceramic and multicomponent Si-based ceramics.     

Improving the ductility of polylactic acid parts produced by fused deposition modeling through polyhydroxyalkanoate additions

Polylactic acid (PLA) is one of the most commonly used materials for fused deposition modeling (FDM) due to its low cost, biocompatibility, and desirable printing characteristics. However, its low ductility is a major disadvantage for engineering applications where high damage tolerance is needed. This study investigates the feasibility of polyhydroxyalkanoate (PHA) additions to PLA for improving the ductility of parts produced by FDM. Thermal and mechanical behavior of PLA/PHA specimens containing 12 wt % PHA is investigated for a range of printing nozzle temperatures. All PLA/PHA specimens exhibit amorphous PLA phase with semicrystalline PHA and possess outstanding ductility exceeding 160% for nozzle temperatures in the range of 200 °C–240 °C. Lower and higher nozzle temperatures result in low ductility, similar to that of pure PLA. Overall, PLA/PHA is a very promising polymer blend for FDM processes, providing a combination of sufficient strength with excellent damage tolerance. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48154.     

陶瓷光固化3D打印技术研究进展及应用

与传统加工方法相比,光固化3D打印技术具有个性化、定制化、高分辨率等优点,可满足陶瓷精细结构的成型,在陶瓷材料加工方面展示出很大的潜力.这里首先介绍了光固化3D打印技术及常见的陶瓷材料,从陶瓷浆料制备、素坯热处理工艺方面进行讨论.同时对该技术在生物医学领域特别是在骨科、齿科中的应用进行总结.     

3D打印成型工艺及其应用研究

从增材制造的实现原理出发,分析了当前几种主流三维（3D）成型工艺的技术特点、设备原理及实现流程。以工业级3D打印机为研究平台,将熔融沉积成型（FDM）工艺应用于复杂型腔结构和传动组件结构的快速成型,通过3D建模、数据转化、切片处理、工艺参数选择、模型包计算及工艺后处理等一系列环节的实践探索,明确了FDM成型工艺的技术原理与应用流程,并成功制作了丙烯腈丁二烯苯乙烯共聚物（ABS）材质的3D打印模型。结果表明,复杂型腔零件切片厚度为0.254 mm、传动组件切片厚度为0.178 mm时,3D成型件具有理想的工艺精度和打印效率。     

3D打印用聚丙烯复合材料的制备及性能研究

将碳酸钙和滑石粉按质量比为1∶1混合,与聚丙烯(PP)共混,制备可用于熔融沉积法(FDM)打印的PP材料,研究填料用量对3D打印试样力学性能和微观结构的影响。结果表明,随着填料用量的增大,3D打印制品的力学性能下降,PP材料的收缩率显著降低,试样内部纤维之间无空隙。当碳酸钙和滑石粉质量各占配方总质量的20%时,3D打印的PP制品性能最好。     

3D打印用ABS丝材性能研究

以丙烯腈–丁二烯–苯乙烯塑料(ABS)为基体,分别以碳酸钙、短切玻璃纤维(GF)和色母粒为改性填料,通过挤出成型制备改性ABS丝材,然后采用3D打印技术中的熔融沉积成型(FDM)技术,通过FDM型3D打印机打印测试试样,对其力学性能及收缩率展开研究。研究结果表明,碳酸钙填料的加入使得ABS 3D打印试样的拉伸强度降低,用量为2份的短切GF可略微提高试样的拉伸强度,但随着GF含量的增加拉伸强度下降;当打印速度不高于50 mm/s时,相比于橘黄色母粒,蓝色母粒可提高试样的拉伸强度;改性ABS试样的拉伸性能随着打印速度的增加呈现两种不同的变化趋势,这可能由材料流动性能的差异所引起;随碳酸钙或GF用量增加,试样的收缩率逐渐降低,其中GF改性ABS试样收缩率的降低幅度更大,相比于橘黄色母粒,蓝色母粒的加入能够更有效地降低ABS试样的收缩率。     

Enhanced dielectric properties of three phase dielectric MWCNTs/BaTiO3/PVDF nanocomposites for energy storage using fused deposition modeling 3D printing

This research studied the effect of fused deposition modeling (FDM) 3D printing on three phase dielectric nanocomposites using poly(vinylidene) fluoride (PVDF), BaTiO₃ (BT), and multiwall carbon nanotubes (CNTs). PVDF polymer and BT ceramics are piezo-, pyro- and di-electric materials extensively used for sensor and energy storage/harvesting applications due to their unique characteristic of dipole polarization. To increase dielectric property, CNTs have been recently utilized for uniform dispersion of BT nanoparticles, ultrahigh polarization density, and local micro-capacitor among matrix. It was proved that 3D printing process provides homogeneous dispersion of nanoparticles, alleviating agglomeration of nanoparticles and reducing micro-crack/voids in matrix which can potentially enhance their dielectric property than traditional methods. In this research, these three-phase nanocomposites are fabricated through FDM 3D printing process and characterized for dielectric property. Increasing both BT and CNT nanoparticles improves dielectric properties, while CNTs have a percolation threshold near 1.7?wt%. The most desirable combination of dielectric constant and loss properties (118 and 0.11 at 1?kHz) is achieved with nanocomposites containing 1.7?wt%-CNT/45?wt%-BT/PVDF. These results provide not only a technique to 3D print dielectric nanocomposites with improved dielectric property but also large-scale electronic device manufacturing possibility with freedom of design, low cost, and faster process.     

三维打印生物材料的发展现状

随着组织工程和再生医学不断进步,3D打印技术被用于开发和制造由仿生天然和合成材料组成的仿生支架。讨论3D打印"生物墨水"的进步和发展趋势,对3D打印多功能生物材料的发展具有积极意义。