Mechanical isotropy and postcure shrinkage of polydimethylsiloxane printed with digital light processing

2020 ◽  
Vol 26 (8) ◽  
pp. 1447-1452
Author(s):  
Dong Sung (Danny) Kim ◽  
Jakkrit Suriboot ◽  
Chin-Cheng Shih ◽  
Austin Cwiklik ◽  
Melissa A. Grunlan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Test ◽  
Design Methodology ◽  
Good Accuracy ◽  
Dimensional Accuracy ◽  
Dimensional Error ◽  
Digital Light Processing ◽  
Content Type ◽  
Post Exposure ◽  
Exposure Conditions

Purpose This paper aims to investigate the printability of photocurable PDMS with digital light processing (DLP) in terms of dimensional accuracy, mechanical properties, isotropy and postcure shrinkage. Design/methodology/approach The photocurable PDMS was made from methacrylated PDMS-macromer and 2,4,6-Trimethylbenzoyldi-Phenylphosphinate (TPO-L) photoinitiator. The PDMS was printed using different orientations, sizes and post-exposure conditions and then evaluated by tensile test and microscope to determine the printability. Findings Printed parts show good accuracy and low shrinkage, but high directionality in modulus, ductility and strength. The dimensional error is less than 2% and the shrinkage rates are less than 0.52%. In contrast, the modulus varies between 0.87 and 0.96 MPa depending on print orientation, elongation varies from 34.7% to 66.4% and strength varies from 0.23 to 0.49 MPa. Originality/value This study quantitatively characterizes the printability of photo curable PDMS with DLP, which has not been reported elsewhere. This paper also discusses the challenges of PDMS printing for future advancement.

Deposition-induced effects of isotactic polypropylene and polycarbonate composites during fused deposition modeling

2017 ◽  
Vol 23 (5) ◽  
pp. 869-880 ◽  
Author(s):  
Ying-Guo Zhou ◽  
Bei Su ◽  
Lih-sheng Turng
Keyword(s):  
Mechanical Properties ◽  
Design Methodology ◽  
Fused Deposition Modeling ◽  
Content Type ◽  
Fused Deposition ◽  
Close Relationship ◽  
Molded Parts ◽  
Deposition Modeling ◽  
Injection Molded ◽  
First Time

Purpose Although the feasibility and effectiveness of the fused deposition modeling (FDM) method have been proposed and developed, studies of applying this technology to various materials are still needed for researching its applicability, especially with regard to polymer blends and composites. The purpose of this paper is to study the deposition-induced effect and the effect of compatibilizers on the mechanical properties of polypropylene and polycarbonate (PP/PC) composites. Design/methodology/approach For this purpose, three different deposition modes for PP/PC composites with or without compatibilizers were used for the FDM method and tested for tensile properties. Also, parts with the same materials were made by injection molding and used for comparison. In addition, different deposition speeds were used to investigate the different deposition-induced effects. Furthermore, the behavior of the mechanical properties was clarified with scanning electron microscope images of the fracture surfaces. Findings The research results suggest that the deposition orientation has a significant influence on the mechanical behavior of PP/PC composite FDM parts. The results also indicate that there is a close relationship between the mechanical properties and morphological structures which are deeply influenced by compatibilization. Compared with injection molded parts, the ductility of the FDM parts can be dramatically improved due to the formation of fibrils and micro-fibrils by the deposition induced during processing. Originality/value This is the first paper to investigate a PP/PC composite FDM process. The results of this paper verified the applicability of PP/PC composites to FDM technology. It is also the first time that the deposition-induced effect during FDM has been investigated and studied.

On the role of different annealing heat treatments on mechanical properties and microstructure of selective laser melted and conventional wrought Ti-6Al-4V

2017 ◽  
Vol 23 (2) ◽  
pp. 295-304 ◽  
Author(s):  
AmirMahyar Khorasani ◽  
Ian Gibson ◽  
Moshe Goldberg ◽  
Guy Littlefair
Keyword(s):  
Mechanical Properties ◽  
Design Methodology ◽  
Stress Relief ◽  
Heat Treatments ◽  
Recrystallization Annealing ◽  
Content Type ◽  
Hardness Increase ◽  
As Stress ◽  
Different Characteristics

Purpose The purpose of this study was to conduct various heat treatments (HT) such as stress relief annealing, mill annealing, recrystallization (α + β) annealing and β annealing followed by furnace cooling (FC) that were implemented to determine the effect of these on mechanical properties and the microstructure of selective laser melted and wrought samples. The mentioned annealings have been carried out to achieve the related standards in the fabrication of surgery implants. Design/methodology/approach In this paper, based on F2924-14 ASTM standard SLM and conventionally wrought parts were prepared. Then HT was performed and different characteristics such as microstructure, mechanical properties, macro-hardness and fracture surface for selective laser melted and wrought parts were analysed. Findings The results show that the high cooling rate in selective laser melting (SLM) generates finer grains. Therefore, tensile strength and hardness increase along with a reduction in ductility was noticed. Recrystallization annealing appears to give the best combination of ductility, strength and hardness for selective laser melted parts, whilst for equivalent wrought samples, increasing HT temperature results in reduction of mechanical properties. Originality/value The contributions of this paper are discussing the effect of different annealing on mechanical properties and microstructural evolution based on new ASTM standards for selective laser melted samples and comparing them with wrought parts.

Optimization of the color fastness and mechanical properties of pigment dyed PC fabric

2018 ◽  
Vol 47 (5) ◽  
pp. 396-405
Author(s):  
Abdul Azeem ◽  
Sharjeel Abid ◽  
Noman Sarwar ◽  
Shahzaib Ali ◽  
Ahsan Maqsood ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Design Methodology ◽  
Industrial Process ◽  
Color Fastness ◽  
Content Type ◽  
Washing Fastness ◽  
Market Values ◽  
Dyed Fabrics ◽  
Bending Length ◽  
Practical Implications

Purpose The purpose of this study is to improve the mechanical properties and reduce the stiffness/harshness of fabric associated with the pigment dyeing of textiles. Design/methodology/approach The fabric was pigment dyed with the addition of three different softeners and binders. The fabric was then analyzed to have improved textile properties by measuring tear strength, bending length, crocking and washing fastness tests. Findings The conventional route of pigment dyeing (without any softener) imparted poor mechanical and rubbing fastness. The softener-added recipe provided better mechanical, rubbing and washing fastness, and the stiffness values were oppressed as well. Practical implications Because of reduced stiffness, increased fastness and mechanical properties, the use of softener with pigment dyeing can improve the market values and satisfaction of the dyed fabrics. The finished product would also have better life and endurance. The process can be modified easily to have a better end-product with a negligible cost addition in industrial process, as softeners are cheap and used in low (10-20 g/l) in industrial settings without affecting the required shades. Originality/value This is the first report, to the best of the author’s knowledge, on the optimization of pigment dyeing of PC fabric with the addition of Helizarin and perapret softeners in dyeing bath.

scholarly journals The use of rapid prototyping in the joining of fractured historical silver object

2018 ◽  
Vol 24 (3) ◽  
pp. 532-538 ◽  
Author(s):  
Maria Luiza Seixas ◽  
Paulo Santos Assis ◽  
João Cura D’Ars Figueiredo ◽  
Maria Aparecida Pinto ◽  
Daniella Gualberto Caldeira Paula
Keyword(s):  
Rapid Prototyping ◽  
Design Methodology ◽  
Mechanical Stability ◽  
Dimensional Accuracy ◽  
3D Modelling ◽  
Content Type ◽  
Minimal Impact ◽  
Speed Up ◽  
Elemental Chemical Analysis ◽  
Original Metal

Purpose This paper aims to present a proposal for the restoration of a silver crown by means of fitting pieces produced by the process of 3D modelling and rapid prototyping. It also analyses the benefits of this procedure in restoration of objects weakened by corrosive processes. Design/methodology/approach Elemental chemical analysis was carried out in the alloy used in the manufacture of the crown and the constructive and corrosive processes present were studied. Three fitting pieces were modelled and prototyped in wax casting by the stereolithography apparatus system aiming to restore the part and protect the original metal against impacts and external tensions which could speed up some deterioration processes. Findings The procedure presented in this paper has shown that formal and dimensional accuracy, only achieved by means of 3D technologies, made the restoration and mechanical stability of the crown possible without the use of adhesives or welding. Originality/value The proposed procedure is a new restoration alternative which causes minimal impact to the object and abides by the main standards for modern conservation. It is made with metal which is compatible with the original piece, retractable and easily identifiable.

Multi-jet ice 3D printing

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Pushkar Prakash Kamble ◽  
Subodh Chavan ◽  
Rajendra Hodgir ◽  
Gopal Gote ◽  
K.P. Karunakaran
Keyword(s):  
Design Methodology ◽  
Good Accuracy ◽  
Microfluidic Channel ◽  
Content Type ◽  
Water Ice ◽  
Volumetric Expansion ◽  
Low Viscosity ◽  
Wide Range ◽  
Water Layers ◽  
Potential Applications

Purpose Multi-jet deposition of the materials is a matured technology used for graphic printing and 3 D printing for a wide range of materials. The multi-jet technology is fine-tuned for liquids with a specific range of viscosity and surface tension. However, the use of multi-jet for low viscosity fluids like water is not very popular. This paper aims to demonstrate the technique, particularly for the water-ice 3 D printing. 3 D printed ice parts can be used as patterns for investment casting, templates for microfluidic channel fabrication, support material for polymer 3 D printing, etc. Design/methodology/approach Multi-jet ice 3 D printing is a novel technique for producing ice parts by selective deposition and freezing water layers. The paper confers the design, embodiment and integration of various subsystems of multi-jet ice 3 D printer. The outcomes of the machine trials are reported as case studies with elaborate details. Findings The prismatic geometries are realized by ice 3 D printing. The accuracy of 0.1 mm is found in the build direction. The part height tends to increase due to volumetric expansion during the phase change. Originality/value The present paper gives a novel architecture of the ice 3 D printer that produces the ice parts with good accuracy. The potential applications of the process are deliberated in this paper.

Evaluation and prediction of material fatigue characteristics under impact loads: review and prospects

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Xintian Liu ◽  
Que Wu ◽  
Shengchao Su ◽  
Yansong Wang
Keyword(s):  
Mechanical Properties ◽  
Design Methodology ◽  
Mechanical Performance ◽  
Impact Load ◽  
Impact Loads ◽  
Content Type ◽  
Material Fatigue ◽  
Mechanical Properties Of Materials ◽  
Fatigue Characteristics ◽  
Properties Of Materials

PurposeThe properties of materials under impact load are introduced in terms of metal, nonmetallic materials and composite materials. And the application of impact load research in biological fields is also mentioned. The current hot research topics and achievements in this field are summarized. In addition, some problems in theoretical modeling and testing of the mechanical properties of materials are discussed.Design/methodology/approachThe situation of materials under impact load is of great significance to show the mechanical performance. The performance of various materials under impact load is different, and there are many research methods. It is affected by some kinds of factors, such as the temperature, the gap and the speed of load.FindingsThe research on mechanical properties of materials under impact load has the characteristics as fellow. It is difficult to build the theoretical model, verify by experiment and analyze the data accumulation.Originality/valueThis review provides a reference for further study of material properties.

On the manufacturability of Inconel 718 thin-walled honeycomb structures by laser powder bed fusion

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
José M. Zea Pérez ◽  
Jorge Corona-Castuera ◽  
Carlos Poblano-Salas ◽  
John Henao ◽  
Arturo Hernández Hernández
Keyword(s):  
Mechanical Properties ◽  
Inconel 718 ◽  
Dimensional Accuracy ◽  
Honeycomb Lattice ◽  
Lattice Structures ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Content Type ◽  
Powder Bed ◽  
Thin Walled

Purpose The purpose of this paper is to study the effects of printing strategies and processing parameters on wall thickness, microhardness and compression strength of Inconel 718 superalloy thin-walled honeycomb lattice structures manufactured by laser powder bed fusion (L-PBF). Design/methodology/approach Two printing contour strategies were applied for producing thin-walled honeycomb lattice structures in which the laser power, contour path, scanning speed and beam offset were systematically modified. The specimens were analyzed by optical microscopy for dimensional accuracy. Vickers hardness and quasi-static uniaxial compression tests were performed on the specimens with the least difference between the design wall thickness and the as built one to evaluate their mechanical properties and compare them with the counterparts obtained by using standard print strategies. Findings The contour printing strategies and process parameters have a significant influence on reducing the fabrication time of thin-walled honeycomb lattice structures (up to 50%) and can lead to improve the manufacturability and dimensional accuracy. Also, an increase in the young modulus up to 0.8 times and improvement in the energy absorption up to 48% with respect to those produced by following a standard strategy was observed. Originality/value This study showed that printing contour strategies can be used for faster fabrication of thin-walled lattice honeycomb structures with similar mechanical properties than those obtained by using a default printing strategy.

Effect of print orientation on microstructural features and mechanical properties of 3D porous structures printed with continuous digital light processing

2019 ◽  
Vol 25 (6) ◽  
pp. 1017-1029
Author(s):  
Javier Navarro ◽  
Matthew Din ◽  
Morgan Elizabeth Janes ◽  
Jay Swayambunathan ◽  
John P. Fisher ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Biaxial Loading ◽  
Digital Light Processing ◽  
Printing Process ◽  
Content Type ◽  
Simple Compression ◽  
Microct Imaging ◽  
Microporous Scaffolds ◽  
Part Orientation

Purpose This paper aims to study the effects of part orientation during the 3D printing process, particularly to the case of using continuous digital light processing (cDLP) technology. Design/methodology/approach The effects of print orientation on the print accuracy of microstructural features were assessed using microCT imaging and mechanical properties of cDLP microporous scaffolds were characterized under simple compression and complex biaxial loading. Resin viscosity was also quantified to incorporate this factor in the printing discussion. Findings The combined effect of print resin viscosity and the orientation and spacing of pores within the structure alters how uncrosslinked resin flows within the construct during cDLP printing. Microstructural features in horizontally printed structures exhibited greater agreement to the design dimensions than vertically printed constructs. While cDLP technologies have the potential to produce mechanically isotropic solid constructs because of bond homogeneity, the effect of print orientation on microstructural feature sizes can result in structurally anisotropic porous constructs. Originality/value This work is useful to elucidate on the specific capabilities of 3D printing cDLP technology. The orientation of the part can be used to optimize the printing process, directly altering parameters such as the supporting structures required, print time, layering, shrinkage or surface roughness. This study further detailed the effects on the mechanical properties and the print accuracy of the printed scaffolds.

Study on mechanical properties of non-dispersible concrete in seawater environment

2019 ◽  
Vol 11 (6) ◽  
pp. 809-818
Author(s):  
Huijun Wu
Keyword(s):  
Mechanical Properties ◽  
Design Methodology ◽  
New Products ◽  
Main Approach ◽  
Content Type ◽  
Concrete Mixtures ◽  
Seawater Environment ◽  
Hardened Properties ◽  
Underwater Concrete ◽  
Working Performance

Purpose The purpose of this paper is to research the hardened properties of non-dispersible concrete in seawater environment, especially in seawater environment. Design/methodology/approach The main approach is according to the experiment. Findings The findings of this paper are: first, because of the washing effect of water, the strength of underwater non-dispersible concrete is lower than that of terrestrial concrete. Second, the strength of non-dispersible underwater concrete with silica fume increases remarkably at different ages. Third, underwater non-dispersible concrete does not produce new products when it is formed and cured in seawater. Originality/value In this paper, underwater non-dispersible concrete is formed and maintained on land, freshwater and seawater by underwater pouring method. The working performance, mechanical properties and durability of underwater non-dispersible concrete mixtures after hardening are tested.

Mechanical properties of interfacial phases between Sn-3.5 Ag solder and Ni-18 at. % W barrier film by nanoindentation

2015 ◽  
Vol 27 (2) ◽  
pp. 90-94 ◽  
Author(s):  
C.S. Chew ◽  
R. Durairaj ◽  
A. S. M. A. Haseeb ◽  
B. Beake
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Solid State ◽  
Design Methodology ◽  
Amorphous Structure ◽  
Alloy Film ◽  
Content Type ◽  
State Amorphization ◽  
Barrier Film

Purpose – The purpose of this paper is to investigate the hardness and elastic modulus on interfacial phases formed between Sn-3.5Ag solder and Ni-18 at. % W alloy film by nanoindentation. It has been found that a ternary amorphous Sn-Ni-W layer formed below Ni3Sn4 IMC at the interface. In this study, mechanical properties of the IMC formed between SA solder and Ni-18 at. % W film after six times reflows were performed by nanoindentation. Design/methodology/approach – The characterization was carried at 25°C, and 100 indents were generated. The elastic modulus and hardness were investigated. Findings – The results showed that hardness of Ni3Sn4 IMC was higher than amorphous Sn-Ni-W phase. A slight bigger indent was observed on the Sn-Ni-W layer compared with that on the Ni3Sn4 IMC. Lower topographical height in the Sn-Ni-W layer indicated that the Sn-Ni-W phase was softer compared with the Ni3Sn4 IMC. The lower hardness and soft Sn-Ni-W phase is significantly related to the amorphous structure that formed through solid-state amorphization. Originality/value – There are no publications about the indentation on the interfacial between the Ni-W layer and the Sn-Ag solder.

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