scholarly journals 3D Printing of Aramid Nanofiber Composites by Stereolithography

2021 ◽  
Author(s):  
Sachini Perera ◽  
Alejandra Durand-Silva ◽  
Ashele Remy ◽  
Shashini Diwakara ◽  
Ronald Smaldone
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Exchange Process ◽  
Polymeric Materials ◽  
Solvent Exchange ◽  
High Quality ◽  
Filler Dispersion ◽  
Printing Method ◽  
Quality Surface ◽  
High Quality Surface

Vat photopolymerization is a versatile 3D printing method that produces parts using polymeric materials with uniform mechanical properties, high quality surface finish and high-resolution features. However, it is challenging to make composite materials with vat photopolymerization mainly due to the imperfect filler dispersion in the photo resin. Herein, we describe a methodology to incorporate aramid nanofibers (ANFs) into a 3D printable photoresin as a dispersion, followed by a solvent exchange process that limits anisotropic shrinkage and cracking of the printed polymer. By incorporating 0.60 wt.% of ANFs, both the tensile strength and toughness increased by 264 % and 219 % respectively, while the Young’s modulus had a 406 % increase compared to the control photoresin.

Severe Plastic Deformation Induced in Al, Al-Si, Ag and Cu by Hydrostatic Extrusion

2014 ◽  
Vol 59 (1) ◽  
pp. 59-64 ◽  
Author(s):  
M. Kulczyk ◽  
S. Przybysz ◽  
J. Skiba ◽  
W. Pachla
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Hydrostatic Extrusion ◽  
Adiabatic Heating ◽  
High Quality ◽  
Aluminum Silicon Alloy ◽  
Quality Surface ◽  
High Quality Surface

Abstract The study was concerned with the effect of severe deformation induced in one pass, by hydrostatic extrusion on the properties of fine aluminum, aluminum-silicon alloy, copper and silver wires. The influence of adiabatic heating which takes place during deformation on the mechanical properties and microstructure of the wires was examined. The quality of the surface of the wires was estimated. It has been demonstrated that fine aluminum and silver wires processed by hydrostatic extrusion have very good mechanical properties and a high-quality surface.

scholarly journals Large-Scale and Deep-Seated Gravitational Slope Deformations on Mars: A Review

Geosciences ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 174
Author(s):  
Marco Emanuele Discenza ◽  
Carlo Esposito ◽  
Goro Komatsu ◽  
Enrico Miccadei
Keyword(s):  
Large Scale ◽  
High Quality ◽  
Surface Data ◽  
Geomorphological Processes ◽  
Gravitational Processes ◽  
Quality Surface ◽  
High Quality Surface ◽  
Mars Missions

The availability of high-quality surface data acquired by recent Mars missions and the development of increasingly accurate methods for analysis have made it possible to identify, describe, and analyze many geological and geomorphological processes previously unknown or unstudied on Mars. Among these, the slow and large-scale slope deformational phenomena, generally known as Deep-Seated Gravitational Slope Deformations (DSGSDs), are of particular interest. Since the early 2000s, several studies were conducted in order to identify and analyze Martian large-scale gravitational processes. Similar to what happens on Earth, these phenomena apparently occur in diverse morpho-structural conditions on Mars. Nevertheless, the difficulty of directly studying geological, structural, and geomorphological characteristics of the planet makes the analysis of these phenomena particularly complex, leaving numerous questions to be answered. This paper reports a synthesis of all the known studies conducted on large-scale deformational processes on Mars to date, in order to provide a complete and exhaustive picture of the phenomena. After the synthesis of the literature studies, the specific characteristics of the phenomena are analyzed, and the remaining main open issued are described.

INVESTIGATION ON HIGH-TEMPERATURE OXIDIZATION OF MIRROR-QUALITY GROUND STAINLESS STEEL

2010 ◽  
Vol 24 (15n16) ◽  
pp. 3005-3010 ◽  
Author(s):  
KAZUTOSHI KATAHIRA ◽  
HITOSHI OHMORI ◽  
MASAYOSHI MIZUTANI ◽  
JUN KOMOTORI
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
High Temperature ◽  
High Quality ◽  
Spinel Type ◽  
Combined Process ◽  
Elid Grinding ◽  
Modification Method ◽  
Quality Surface ◽  
High Quality Surface

To investigate the possibility of developing a new surface modification method by the combined process of ELID grinding and high-temperature oxidization, we treated ELID finished specimens and polished specimens by high-temperature oxidization in the atmosphere and performed detailed analysis to determine how the treatment would change the specimen surfaces. The ELID-series showed high quality surface roughness and excellent tribological characteristics as compared with the polished-series. The improved surface properties of the ELID-series seem to result from formation of fine, uniform structures of spinel-type multiple oxides FeCr 2 O 4 and Cr 2 O 3 on the surface by high-temperature oxidization.

Investigation of the Influence of Fillers of Various Nature on the Properties of Polyether Sulfone and Determination of the Possibility of Using Composites on their Basis in 3D-Printing

2018 ◽  
Vol 935 ◽  
pp. 11-14
Author(s):  
Azamat L. Slonov ◽  
Azamat A. Zhansitov ◽  
Ismel V. Musov ◽  
Elina V. Khakyasheva ◽  
L.Kh. Kuchmenova ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
3D Printing ◽  
Carbon Fibers ◽  
Polymer Matrix ◽  
Polyether Sulfone ◽  
Printing Method

The results of the studies of the effect of excipients of mineral and organic origin on the mechanical properties of polyether sulfone based on 4,4'-dihydroxydiphenyl and 4,4'-dichlordiphenylsulfone are adduced. It has been shown that the introduction of hard fillers is accompanied by the increased modulus and reduced ductility of the polymer matrix, the intensity of these effects depends on the concentration, shape and particle size additives. It was revealed that the composites with talc and discrete carbon fibers were characterized by higher mechanical properties. Their test as materials for FDM 3D printing method shows the highest suitability composites with talc for this technology.

scholarly journals Achieving high quality surface of laminated glass-reinforced plastics during milling

2018 ◽  
Vol 224 ◽  
pp. 01044 ◽  
Author(s):  
Daniel Rychkov ◽  
Dmitry Lobanov ◽  
Aleksey Kuznetsov
Keyword(s):  
Glass Fiber ◽  
Cutting Speed ◽  
Laminated Composite ◽  
High Strength ◽  
High Quality ◽  
Fiber Plastic ◽  
Flank Surface ◽  
Cutting Modes ◽  
Quality Surface ◽  
High Quality Surface

Milling is one of the most common ways of workpiece machining, but obtaining a high quality surface of laminated composite materials is difficult due to their layered structure, high strength characteristics and low heat conductivity. This poses a problem of creating a milling technology that provides a high quality surface. This research investigates STEF -1 glass-fiber plastic with fine grain structure processed on the equipment with high cutting speed. The object of the research is roughness Ra as a quality criterion. Our glass-fiber plastic milling experiments demonstrate that the surface quality depends to a large extent on the cutting modes and the wear level of the tool cutting edge which is determined by the size of the wear bevel on the flank surface. The blade of the cutting tool is established to wear unevenly during glass-fiber plastic processing as it interacts with two different materials. We recommend the wear bevel on the flank surface to be less than 0.35 mm to ensure the high quality of the laminated composite material surface. The cutting modes should be within the following range: feed per tooth is 0.15 ÷ 0.17 mm/tooth, cutting depth is 0.5 ÷ 0.9 mm, cutting speed is above 45 m/s, with the cutting part of the tool being made of high-strength instrumental materials.

Investigation on Smoothing Silicon Carbide Wafer With a Combined Method of Mechanical Lapping and Photocatalysis Assisted Chemical Mechanical Polishing

2018 ◽  
Author(s):  
Zewei Yuan ◽  
Kai Cheng ◽  
Yan He ◽  
Meng Zhang
Keyword(s):  
Silicon Carbide ◽  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Removal Rate ◽  
Mechanical Polishing ◽  
Combined Method ◽  
Polishing Process ◽  
High Quality ◽  
Quality Surface ◽  
High Quality Surface

The high quality surface can exhibit the irreplaceable application of single crystal silicon carbide in the fields of optoelectronic devices, integrated circuits and semiconductor. However, high hardness and remarkable chemical inertness lead to great difficulty to the smoothing process of silicon carbide. Therefore, the research presented in this paper attempts to smooth silicon carbide wafer with photocatalysis assisted chemical mechanical polishing (PCMP) by using of the powerful oxidability of UV photo-excited hydroxyl radical on surface of nano-TiO2 particles. Mechanical lapping was using for rough polishing, and a material removal model was proposed for mechanical lapping to optimize the polishing process. Several photocatalysis assisted chemical mechanical polishing slurries were compared to achieve fine surface. The theoretical analysis and experimental results indicate that the material removal rate of lapping process decreases in index form with the decreasing of abrasive size, which corresponds with the model developed. After processed with mechanical lapping for 1.5 hours and subsequent photocatalysis assisted chemical mechanical polishing for 2 hours, the silicon carbide wafer obtains a high quality surface with the surface roughness at Ra 0.528 nm The material removal rate is 0.96 μm/h in fine polishing process, which is significantly influenced by factors such as ultraviolet irradiation, electron capture agent (H2O2) and acidic environment. This combined method can effectively reduce the surface roughness and improve the polishing efficiency on silicon carbide and other hard-inert materials.

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