R-curve of La2O3 doped Zirconia Toughened Alumina Composites Prepared via Stereolithography based 3D Printing

2020 ◽  
Author(s):  
Haidong Wu ◽  
W. Liu ◽  
Meipeng Huang ◽  
Jianwei Liang ◽  
Di An ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
3D Printing ◽  
Crack Size ◽  
Liquid Precursor ◽  
Zro2 Phase ◽  
Alumina Composites ◽  
3D Printed ◽  
First Time ◽  
New Phase ◽  
Zirconia Toughened Alumina

Abstract In this study, we combined liquid precursor infiltration of high introduction amounts of bi-additives (20wt%) and stereolithography-based 3D printing to fabricate zirconia toughened alumina, and the infiltration systems consist of the four following systems Zr4+/La3+, Zr4+/Er3+, Zr4+/Gd3+, and Zr4+/Ce4+. The sample immersed with Zr4+/La3+ shows intense peaks of m-ZrO2 phase compared to the other samples while a new phase of flake-like LaAl11O18 occurs in the Zr4+/La3+ immersed sample, the existence of which could be confirmed by XRD and EDS. The fracture toughness of the Zr4+/Er3+, Zr4+/Gd3+, and Zr4+/Ce4+ samples remained basically unchanged versus the crack size, while the measured fracture toughness values for the Zr4+/La3+ system could be fitted as a rising R-curve behavior with the steady-state fracture toughness of 17.76 MPa·m1/2. The enormous enhancement of the toughness could be attributed to thermal expansion misfit and flake-like LaAl11O18 in the Zr4+/La3+ system. The effect of residual stresses on the fracture mode and thus the toughness is discussed on the basis of theoretical calculation and analysis. It is the first time a rising R-curve behavior is observed in the 3D printed ceramics. The shocking discovery provides a highly effective toughening way in 3D printing combined infiltration approach.

Mechanical Properties of Zirconia Toughened Alumina Composites with TZP Partially Nanostructured Sintered by Liquid Fase

2008 ◽  
Vol 591-593 ◽  
pp. 436-440
Author(s):  
João Marcos K. Assis ◽  
Francisco Piorino Neto ◽  
Francisco Cristóvão Lourenço de Melo ◽  
Maria do Carmo de Andrade Nono
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Weibull Modulus ◽  
Bending Test ◽  
Sintering Aid ◽  
Zirconia Composites ◽  
Alumina Composites ◽  
Grain Size And Shape ◽  
Zirconia Toughened Alumina ◽  
Zirconia Powders

A comparative study between alumina added niobia ceramics and two alumina zirconia composites from nanostructured TZP (7% and 14% weight) was made. On this composites the zirconia were yttria stabilized and the alumina were submicron structured. As sintering aid a mixture of magnesia, niobia and talc were used on all samples. The sintering was performed at 1450 oC during 60 minutes. The characteristic grain size and shape of an alumina and zirconia powders, aggregates and agglomerates were characterized. The sintering ceramics were evaluated through hardness, fracture toughness and 4 point bending test. Weibull statistic was applied on the flexural results. Although the fracture toughness result from ZTA were lower, and seems to be affected by the liquid fase, the hardness and Weibull modulus were higher than alumina niobia. The grains size and the homogeneity of its distributions on the microstructure of this ceramics was correlated to these higher values. The results from these alumina zirconia composites showed a potential to apply as a ballistic armor material.

scholarly journals Printability and properties of 3D-printed poplar fiber/polylactic acid biocomposite

BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 2774-2788
Author(s):  
Zhaozhe Yang ◽  
Xinhao Feng ◽  
Min Xu ◽  
Denis Rodrigue
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Rheological Properties ◽  
Layer Thickness ◽  
Polylactic Acid ◽  
Physical And Mechanical Properties ◽  
Longitudinal Stripe ◽  
3D Printed ◽  
First Time ◽  
Printing Parameters

To efficiently and economically utilize a wood-plastic biocomposite, an eco-friendly biocomposite was prepared using modified poplar fiber and polylactic acid (PLA) via 3D printing technology for the first time. First, the effects of poplar fiber (0, 1, 3, 5, 7, and 9%) on the mechanical and rheological properties of the printed biocomposites were investigated. Subsequently, the printing parameters, including printing temperature, speed, and layer thickness, were optimized to obtain the biocomposite with superior properties. Finally, four printing orientations were applied to the biocomposite based on the optimized printing parameters to study the effect of filament orientation on the properties of the biocomposite. Favorable printability and mechanical properties of the biocomposite were obtained at 5% poplar fiber. The optimal printing temperature of 220 °C, speed of 40 mm/s, and layer thickness of 0.2 mm were obtained to produce the desired mechanical properties of the biocomposite with the printing orientation in a longitudinal stripe. However, the printing parameters should be chosen according to the applications, where different physical and mechanical properties are needed to achieve efficient and economical utilization of the biocomposites.

3D Printing and Growth Induced Bending based on PET-RAFT Polymerization

2020 ◽  
Author(s):  
Chris Bainbridge ◽  
Kyle Engel ◽  
Jianyong Jin
Keyword(s):  
3D Printing ◽  
Surface Properties ◽  
Raft Polymerization ◽  
Advanced Manufacturing ◽  
3D Printer ◽  
4D Printing ◽  
Printing Process ◽  
Raft Agent ◽  
3D Printed ◽  
First Time

4D printing has steadily become an emerging area of advanced manufacturing research and has produced some truly fantastic innovations. Previously we have demonstrated the 3D printing process based on PET-RAFT polymerization, and its subsequent capability in the post-production modification of surface properties. In this work, (1) we further optimized the PET-RAFT 3D printing formulation by replacing RAFT agent CDTPA with BTPA and adjusting the monomers composition; (2) we also observed the photodegradation of the photocatalysts EB and EY under 405nm light and the effects this has on 3D printing; (3) we then did successful 3D printing using a commercial 405nm DLP 3D printer, with an improved build speed of up to 2286 µm/hr; (4) lastly, for the first time we have demonstrated a method for growth induced bending of a 3D printed strip, where the growth on one side of the strip causes stress and the strip bends accordingly to reach a more comfortable position.

scholarly journals Towards Distributed Recycling with Additive Manufacturing of PET Flake Feedstocks

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4273
Author(s):  
Helen A. Little ◽  
Nagendra G. Tanikella ◽  
Matthew J. Reich ◽  
Matthew J. Fiedler ◽  
Samantha L. Snabes ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Thermal Characterization ◽  
3D Print ◽  
Wide Range ◽  
3D Printed ◽  
Sequential Combination ◽  
Future Work ◽  
The Impact ◽  
First Time

This study explores the potential to reach a circular economy for post-consumer Recycled Polyethylene Terephthalate (rPET) packaging and bottles by using it as a Distributed Recycling for Additive Manufacturing (DRAM) feedstock. Specifically, for the first time, rPET water bottle flake is processed using only an open source toolchain with Fused Particle Fabrication (FPF) or Fused Granular Fabrication (FGF) processing rather than first converting it to filament. In this study, first the impact of granulation, sifting, and heating (and their sequential combination) is quantified on the shape and size distribution of the rPET flakes. Then 3D printing tests were performed on the rPET flake with two different feed systems: an external feeder and feed tube augmented with a motorized auger screw, and an extruder-mounted hopper that enables direct 3D printing. Two Gigabot X machines were used, each with the different feed systems, and one without and the latter with extended part cooling. 3D print settings were optimized based on thermal characterization, and both systems were shown to 3D print rPET directly from shredded water bottles. Mechanical testing showed the importance of isolating rPET from moisture and that geometry was important for uniform extrusion. The mechanical strength of 3D-printed parts with FPF and inconsistent flow is lower than optimized fused filament, but adequate for a wide range of applications. Future work is needed to improve consistency and enable water bottles to be used as a widespread DRAM feedstock.

scholarly journals Embedding Carbon Dots in Superabsorbent Polymers for Additive Manufacturing

Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 921 ◽  
Author(s):  
Yiqun Zhou ◽  
Keenan Mintz ◽  
Cagri Oztan ◽  
Sajini Hettiarachchi ◽  
Zhili Peng ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Citric Acid ◽  
3D Printing ◽  
Carbon Dots ◽  
High Yield ◽  
Sodium Polyacrylate ◽  
Superabsorbent Polymers ◽  
Low Degree ◽  
3D Printed ◽  
First Time

A type of orange carbon dots (O-CDs) synthesized via an ultrasonication route with citric acid and 1,2-phenylenediamine as precursors was embedded into sodium polyacrylate (SPA) as the ink for 3D printing. Characterizations of these spherical O-CDs revealed an ultra-small size (~2 nm) and excitation-independent, but solvent dependent, emission. The O-CDs were evenly distributed with low degree of aggregation in sodium polyacrylate (SPA), which was achieved due to the property that SPA can absorb water together with O-CDs. The 3D printed photoluminescent objective with the ink revealed a great potential for high yield application of these materials for additive manufacturing. This also represents the first time, bare CDs have been reported as a photoluminescent material in 3D printing, as well as the first time SPA has been reported as a material for 3D printing.

Study of the anisotropy of the properties of the ceramic cutting insert obtained by the LCM technology of 3D printing from the composite Al2O3/ZrO2 (ZTA)

2021 ◽  
Vol 87 (11) ◽  
pp. 64-69
Author(s):  
G. V. Shcherbak ◽  
A. A. Murashov ◽  
K. E. Smetanina ◽  
M. M. Vostokov ◽  
M. S. Boldin
Keyword(s):  
Fracture Toughness ◽  
Phase Composition ◽  
3D Printing ◽  
Bending Test ◽  
Indentation Method ◽  
Load Range ◽  
High Adhesion ◽  
Cutting Insert ◽  
3D Printed ◽  
Knoop Indenter

The anisotropy of the properties of a ceramic cutting insert (for three faces) obtained by the lithography-based technology from the Al2O3 + ZrO2 composite has been studied. The study was carried out using the indentation method and Mayer’s law. This method, in contrast to the bending test, excludes the sample destruction. All the studies were carried out on three faces of a ceramic cutting insert made of a composite Al2O3 + ZrO2. The behavior of the Mayer index was studied in the range of loads from 2 to 20 kg and from 0.2 to 1 kg. The results of studying the density, phase composition and microstructure of each face of the sample are presented. The study of the adhesion of the printed layers were also carried out using a Knoop indenter. No anisotropy of the hardness was observed in the load range up to 10 kg. It is shown that a layered structure present in the sample, contributes to the hardness anisotropy under the load of 20 kg and more. No anisotropy of the fracture toughness is observed in the load range of 2 – 20 kg. The results of using a Knoop indenter revealed a high adhesion between 3D printed layers. Studies using a Knoop indenter have indicated high adhesion between the layers of 3D printing.

A 3D-printed adaptive cloaking–illusion-integrated metasurface

2020 ◽  
Vol 8 (45) ◽  
pp. 16018-16023
Author(s):  
Qingxuan Liang ◽  
Zhaohui Li ◽  
Zijie Jiang ◽  
Yubing Duan ◽  
Tianning Chen ◽  
...  
Keyword(s):  
3D Printing ◽  
Injection Molding ◽  
Liquid Metals ◽  
Printing Technology ◽  
3D Printing Technology ◽  
3D Printed ◽  
First Time

An adaptive cloaking–illusion-integrated metasurface is realized for the first time by combining stereolithography of 3D printing technology and injection molding of liquid metals.

3D Printed Integrated Microfluidic Cooling for High Power RF Applications

2017 ◽  
Vol 2017 (1) ◽  
pp. 000675-000680 ◽  
Author(s):  
Michael Craton ◽  
Mohd Ifwat Mohd Ghazali ◽  
Brian Wright ◽  
Kyoung Youl Park ◽  
Premjeet Chahal ◽  
...  
Keyword(s):  
3D Printing ◽  
Microfluidic Channel ◽  
Rf Circuits ◽  
Copper Plate ◽  
Power Supplies ◽  
Plastic Substrate ◽  
Microfluidic Channels ◽  
Channel Integration ◽  
3D Printed ◽  
First Time

Abstract This paper presents the design and fabrication of microfluidic channel integration in a plastic substrate using 3D printing. The microfluidic channels are integrated along with a copper plate which the coolant is in direct contact with. To demonstrate the design, a diode intended for switched power supplies is integrated onto the copper plate and its performance characterized. 3D printing or additive manufacturing (AM) allows for fast prototyping of such package designs and can be readily adopted in the fabrication of RF circuits. This paper, to the best of our knowledge, for the first time will demonstrate a 3D printed integrated microfluidic channel for the cooling of electronic circuits. Details of design, fabrication and characterization are presented.

scholarly journals 3D Printing and Growth Induced Bending based on PET-RAFT Polymerization

2020 ◽  
Author(s):  
Chris Bainbridge ◽  
Kyle Engel ◽  
Jianyong Jin
Keyword(s):  
3D Printing ◽  
Surface Properties ◽  
Raft Polymerization ◽  
Advanced Manufacturing ◽  
3D Printer ◽  
4D Printing ◽  
Printing Process ◽  
Raft Agent ◽  
3D Printed ◽  
First Time

4D printing has steadily become an emerging area of advanced manufacturing research and has produced some truly fantastic innovations. Previously we have demonstrated the 3D printing process based on PET-RAFT polymerization, and its subsequent capability in the post-production modification of surface properties. In this work, (1) we further optimized the PET-RAFT 3D printing formulation by replacing RAFT agent CDTPA with BTPA and adjusting the monomers composition; (2) we also observed the photodegradation of the photocatalysts EB and EY under 405nm light and the effects this has on 3D printing; (3) we then did successful 3D printing using a commercial 405nm DLP 3D printer, with an improved build speed of up to 2286 µm/hr; (4) lastly, for the first time we have demonstrated a method for growth induced bending of a 3D printed strip, where the growth on one side of the strip causes stress and the strip bends accordingly to reach a more comfortable position.

Phase separation in sol gel-derived ceramic films of silica-zirconia, alumina-zirconia, and titania-zirconia system

1994 ◽  
Vol 52 ◽  
pp. 646-647
Author(s):  
J. Tong ◽  
L. Eyring
Keyword(s):  
Fracture Toughness ◽  
Phase Separation ◽  
Sol Gel ◽  
Great Influence ◽  
High Strength ◽  
Chemical Durability ◽  
Separation Method ◽  
Toughening Mechanism ◽  
Ceramic Films ◽  
Zirconia Toughened Alumina

There is increasing interest in composites containing zirconia because of their high strength, fracture toughness, and its great influence on the chemical durability in glass. For the zirconia-silica system, monolithic glasses, fibers and coatings have been obtained. There is currently a great interest in designing zirconia-toughened alumina including exploration of the processing methods and the toughening mechanism.The possibility of forming nanocrystal composites by a phase separation method has been investigated in three systems: zirconia-alumina, zirconia-silica and zirconia-titania using HREM. The morphological observations initially suggest that the formation of nanocrystal composites by a phase separation method is possible in the zirconia-alumina and zirconia-silica systems, but impossible in the zirconia-titania system. The separation-produced grain size in silica-zirconia system is around 5 nm and is more uniform than that in the alumina-zirconia system in which the sizes of the small polyhedron grains are around 10 nm. In the titania-zirconia system, there is no obvious separation as was observed in die alumina-zirconia and silica-zirconia system.

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