A Benchmark Artifact to Evaluate the Manufacturing of Microfeatures by Digital Light Processing Stereolithography

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Lara Rebaioli ◽  
Irene Fassi
Keyword(s):  
Layer Thickness ◽  
Exposure Time ◽  
Process Parameters ◽  
Dimensional Accuracy ◽  
Main Process ◽  
Process Performance ◽  
Digital Light Processing ◽  
Specific Process ◽  
Experimental Campaign ◽  
Increasing Demand

Abstract Suitable benchmark artifacts are needed for assessing the technological capabilities and limitations of a specific process or for comparing the performances of different processes. Only a few benchmark artifacts have been specifically designed for features with microscale dimensions, even if their manufacturing is becoming very common due to the increasing demand for miniaturized parts or objects with microscale features. In this study, a suitable benchmark part is designed to evaluate the geometrical performance of a digital light processing (DLP) stereolithography (SLA) system for manufacturing microfeatures. The effect of the main process parameters (i.e., layer thickness and exposure time) and the feature position within the building platform on the process performance was assessed by a specifically studied experimental campaign. The results show that both the analyzed process parameters influence the minimum feasible size of protruding features and that the feature position influences the dimensional accuracy.

Experimental Investigation of Microfluidic Feature Manufacturing by Digital Light Processing Stereolithography

2020 ◽  
Author(s):  
Lara Rebaioli ◽  
Irene Fassi
Keyword(s):  
Process Parameters ◽  
Low Cost ◽  
Dimensional Accuracy ◽  
Machine Building ◽  
Single Step ◽  
Main Process ◽  
Single Chip ◽  
Digital Light Processing ◽  
And Performance ◽  
User Friendly

Abstract Lab on Chips (LOCs) are devices, mostly based on microfluidics, that allow to perform one or several chemical, biochemical or biological analysis in a miniaturized format on a single chip. The Additive Manufacturing processes, and in particular the Digital Light Processing stereolithography (DLP-SLA), could quickly produce a complete LOC with high resolution 3D features in a single step, i.e. without the need for assembly processes, and using low cost and user-friendly desktop machines. However, the potential of DLP-SLA to produce non-planar channels or channels with complex sections has not been fully investigated yet. This study proposes a benchmark artifact (including also some channels with their axis lying in a plane parallel to the machine building platform) aiming at assessing the capability and performance of DLP-SLA for manufacturing microfeatures for microfluidic devices. A proper experimental campaign was performed to evaluate the effect of the main process parameters (namely, layer thickness and exposure time) on the process performance. The results pointed out that both the process parameters influence the quality and dimensional accuracy of the analyzed features.

Preliminary Study on the Manufacturing Feasibility of Microfeatures for Microfluidics by DLP Stereolithography

2019 ◽  
Author(s):  
Lara Rebaioli ◽  
Irene Fassi
Keyword(s):  
Process Parameters ◽  
Cross Sections ◽  
Dimensional Accuracy ◽  
Single Step ◽  
Main Process ◽  
Single Chip ◽  
Feature Size ◽  
Digital Light Processing ◽  
3D Shapes ◽  
Am Processes

Abstract Lab on Chips (LOCs) are devices mostly based on microfluidics (i.e. structures for liquid handling with cross sections of 1–500 μm and femtoliter to nanoliter volume capacity), which allow to perform one or several chemical, biochemical or biological analysis in a miniaturized format on a single chip. The emerging Additive Manufacturing (AM) processes could produce a complete LOC with microscale complex 3D shapes in a single step without the need for assembly processes. Stereolithography, especially when exploiting the Digital Light Processing (DLP) technology, is the most promising AM process for this purpose. In this study, a suitable benchmark part was designed to assess the feasibility of manufacturing microfeatures by DLP-SLA and to evaluate the performance of the employed system in terms of the minimum feature size, dimensional accuracy and spatial repeatability. A proper experimental campaign was specifically studied to point out the effect of the main process parameters (namely, layer thickness and exposure time) and the feature position within the building platform on the process performance. The results demonstrated the manufacturing feasibility of the selected microfeatures. Moreover, they showed that both the process parameters influence the minimum feasibile feature size and that the dimensional accuracy changes with the feature position.

Research on Warpage of Polystyrene in Selective Laser Sintering

2010 ◽  
Vol 43 ◽  
pp. 578-582 ◽  
Author(s):  
C.Y. Wang ◽  
Q. Dong ◽  
X.X. Shen
Keyword(s):  
Layer Thickness ◽  
Process Parameters ◽  
Laser Power ◽  
Selective Laser Sintering ◽  
Scanning Speed ◽  
Laser Sintering ◽  
Main Process ◽  
Influence Of Process Parameters ◽  
Temperature Changes ◽  
Hatch Spacing

Warpage is a crucial factor to accuracy of sintering part in selective laser sintering (SLS) process. In this paper, The influence of process parameters on warpage when sintering polystyrene(PS) materials in SLS are investigated. The laser power, scanning speed, hatch spacing, layer thickness as well as temperature of powder are considered as the main process parameters. The results showed that warpage increases with the increase of hatch space. Contary to it, warpage decreases with the increase of laser power. Warpage decreases with the increase of layer thickness between 0.16~0.18mm and changes little with increase of the thickness. Warpage increases along with the increase of scanning speed but decreases when the speed is over about 2000mm/s. When the temperature changes between 82°C-86°C, warpage decreases little with the increase of temperature. But further increase of temperature leads to warpage decreasing sharply when the temperature changes between 86°C-90°C.

Large-Diameter Line Pipe Expanding Process

2012 ◽  
Vol 192 ◽  
pp. 180-184 ◽  
Author(s):  
Ai Xia He ◽  
Rong Chang Li
Keyword(s):  
Process Parameters ◽  
Large Diameter ◽  
Dimensional Accuracy ◽  
Optimization Method ◽  
Main Process ◽  
Shape Accuracy ◽  
Line Pipe ◽  
Factors Affecting ◽  
Array Optimization

Mechanical expanding process for large diameter line pipe, a detailed analysis of factors affecting the quality of the final products of the mechanical expansion and proposed optimization using orthogonal array optimization method, as an indicator of dimensional accuracy and shape accuracy of the products, combination of a variety of specifications of mechanical expanding products, the main process parameters to be optimized. Analysis and discussion of results, revealing the degree of influence of various factors on the quality of the final product, and gives the optimum combination of the results. Experiments show that the combination of optimized process parameters, and more help to improve the accuracy of the size and shape of products.

scholarly journals Machinability and Energy Efficiency in Micro-EDM Milling of Zirconium Boride Reinforced with Silicon Carbide Fibers

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3920 ◽  
Author(s):  
Mariangela Quarto ◽  
Giuliano Bissacco ◽  
Gianluca D’Urso
Keyword(s):  
Energy Efficiency ◽  
Process Parameters ◽  
Advanced Materials ◽  
Cavity Surface ◽  
Main Process ◽  
Zirconium Boride ◽  
Electrode Wear ◽  
Micro Edm ◽  
Process Performance ◽  
Sic Fibers

Several types of advanced materials have been developed to be applied in many industrial application fields to satisfy the high performance required. Despite this, research and development of process suited to machine are still limited. Due to the high mechanical properties, advanced materials are often considered as difficult to cut. For this reason, EDM (Electrical Discharge Machining) can be defined as a good option for the machining of micro components made of difficult to cut electrically conductive materials. This paper presents an investigation on the applicability of the EDM process to machine ZrB2 reinforced by SiC fibers, with assessment of process performance and energy efficiency. Different fractions of the additive SiC fibers were taken into account to evaluate the stability and repeatability of the process. Circular pocket features were machined by using a micro-EDM machine and the results from different process parameters combinations were analyzed with respect to material removal, electrode wear and cavity surface quality. Discharges data were collected and characterized to define the actual values of process parameters (peak current, pulse duration and energy per discharge). The characteristics of the pulses were used to evaluate the machinability and to investigate the energy efficiency of the process. The main process performance indicators were calculated as a function of the number of occurred discharges and the energy of a single discharge. The results show interesting aspects related to the process from both the performances and the removal mechanism point of view.

scholarly journals Controlling the porosity of 316L stainless steel parts manufactured via the powder bed fusion process

2019 ◽  
Vol 25 (1) ◽  
pp. 162-175 ◽  
Author(s):  
Abdullah AlFaify ◽  
James Hughes ◽  
Keith Ridgway
Keyword(s):  
Stainless Steel ◽  
Layer Thickness ◽  
Exposure Time ◽  
Process Parameters ◽  
Pulsed Laser ◽  
Powder Bed Fusion ◽  
Content Type ◽  
Powder Bed ◽  
Point Distance ◽  
Part Density

Purpose The pulsed-laser powder bed fusion (PBF) process is an additive manufacturing technology that uses a laser with pulsed beam to melt metal powder. In this case, stainless steel SS316L alloy is used to produce complex components. To produce components with acceptable mechanical performance requires a comprehensive understanding of process parameters and their interactions. This study aims to understand the influence of process parameters on reducing porosity and increasing part density. Design/methodology/approach The response surface method (RSM) is used to investigate the impact of changing critical parameters on the density of parts manufactured. Parameters considered include: point distance, exposure time, hatching distance and layer thickness. Part density was used to identify the most statistically significant parameters, before each parameter was analysed individually. Findings A clear correlation between the number and shape of pores and the process parameters was identified. Point distance, exposure time and layer thickness were found to significantly affect part density. The interaction between these parameters also critically affected the development of porosity. Finally, a regression model was developed and verified experimentally and used to accurately predict part density. Research limitations/implications The study considered a range of selected parameters relevant to the SS316L alloy. These parameters need to be modified for other alloys according to their physical properties. Originality/value This study is believed to be the first systematic attempt to use RSM for the design of experiments (DOE) to investigate the effect of process parameters of the pulsed-laser PBF process on the density of the SS316L alloy components.

An assessment of the dimensional accuracy and geometry-resolution limit of desktop stereolithography using response surface methodology

2019 ◽  
Vol 25 (7) ◽  
pp. 1169-1186 ◽  
Author(s):  
Ivana Cotabarren ◽  
Camila Andrea Palla ◽  
Caroline Taylor McCue ◽  
Anastasios John Hart
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Layer Thickness ◽  
Orientation Angle ◽  
Dimensional Accuracy ◽  
Process Performance ◽  
Feature Location ◽  
Resolution Limit ◽  
Content Type ◽  
Dimensional Deviation

Purpose This paper aims to apply a robust methodology to establish relationships between user-configurable process parameters of commercial desktop stereolithography (SLA) printers and dimensional accuracy of a custom-designed test artifact. Design/methodology/approach A detailed response surface methodology study, Box–Behnken incomplete factorial design of four factors with three levels, was carried out to evaluate process performance of desktop SLA printers. The selected factors were as follows: printing orientation angle in x-direction, printing orientation angle in y-direction, position on build platform in spatial x-coordinate, position on build tray in spatial y-coordinate and layer thickness. The proposed artifact was designed to include 12 feature groups including thin walls, holes, bosses, bridges and overhangs. Two responses were associated with the features: the dimensional deviation according to the designed value and the minimum feature size. Findings Layer thickness was the most significant factor in 70% of the analyzed responses. For example, measurement deviation was reduced about 90% when cylindrical holes were printed with the lowest layer thickness. Further, in many cases, dimensional deviation was minimized for features at the center of the platform, where the beam cures the resin in a straight line. However, at distant positions, accuracy could be improved by compensating for beam deviation by changing the object orientation angle. Originality/value The findings of this study can serve, both generally and specifically, for SLA designers and engineers who wish to optimize printing process variables and feature location to achieve high-dimensional accuracy and further understand the many coupled considerations among part design, build configuration and process performance.

On Technologies of Electrochemical Finishing with Pulsed Current

2012 ◽  
Vol 522 ◽  
pp. 41-46
Author(s):  
Adayi Xieeryazidan ◽  
Muhetar Wumerhali ◽  
Gui Bing Pang
Keyword(s):  
Surface Quality ◽  
Process Parameters ◽  
Dimensional Accuracy ◽  
Experimental Results ◽  
Main Process ◽  
Pulsed Current ◽  
Electrode Gap ◽  
Electric Parameter ◽  
Machining Quality ◽  
Electrochemical Finishing

Electrochemical finishing with pulsed current (ECFP) is introduced in this paper. The main process parameters, such as electric parameter and inter-electrode gap, etc., were investigated. The results show that the ECFP is an effective finishing method for improving the machining quality as the result of the machining mechanism. The related experimental results show that the obtained surface quality and dimensional accuracy are improved significantly as the result of the application of the pulsed current. Moreover, machining quality is increased with shorter pulses.

The Optimization Design Study of Selective Laser Sintering Process Parameters on the Pro-Coated Sand Mold

2011 ◽  
Vol 55-57 ◽  
pp. 853-858
Author(s):  
Rong Cheng ◽  
Xiao Yu Wu ◽  
Jian Ping Zheng
Keyword(s):  
Layer Thickness ◽  
Process Parameters ◽  
Laser Power ◽  
Selective Laser Sintering ◽  
Dimensional Accuracy ◽  
Processing Parameters ◽  
Laser Sintering ◽  
Process Variables ◽  
Scan Speed ◽  
Coated Sand

This paper presents experimental investigations on influence of important process parameters viz., laser power, scan speed, layer thickness, hatching space along with their interactions on dimensional accuracy of Selective Laser Sintering (SLS) processed pro-coated sand mold. It is observed that dimensional error is dominant along length and width direction of built mold. Optimum parameters setting to minimize percentage change in length and width of standard test specimen have been found out using Taguchi’s parameter design. Optimum process conditions are obtained by analysis of variance (ANOVA) is used to understand the significance of process variables affecting dimension accuracy. Scan speed and hatching space are found to be most significant process variables influencing the dimension accuracy in length and width. And laser power and layer thickness are less influence on the dimension accuracy. The optimum processing parameters are attained in this paper: laser power 11 W; scan speed 1200 mm/s; layer thickness 0.5 mm and hatching space 0.25 mm. It has been shown that, on average, the dimensional accuracy under this processing parameters combination could be improved by approximately up to 25% compared to other processing parameters combinations.

scholarly journals 3D printing with moondust

2016 ◽  
Vol 22 (6) ◽  
pp. 864-870 ◽  
Author(s):  
Athanasios Goulas ◽  
Ross J. Friel
Keyword(s):  
Process Parameters ◽  
Lunar Regolith ◽  
Dimensional Accuracy ◽  
Main Process ◽  
Material Particle ◽  
Content Type ◽  
Material Hardness ◽  
Lunar Regolith Simulant ◽  
Potential Applicability ◽  
Relative Porosity

Purpose The purpose of this paper is to investigate the effect of the main process parameters of laser melting (LM) type additive manufacturing (AM) on multi-layered structures manufactured from JSC-1A Lunar regolith (Moondust) simulant powder. Design/methodology/approach Laser diffraction technology was used to analyse and confirm the simulant powder material particle sizes and distribution. Geometrical shapes were then manufactured on a Realizer SLM™ 100 using the simulant powder. The laser-processed samples were analysed via scanning electron microscopy to evaluate surface and internal morphologies, X-ray fluorescence spectroscopy to analyse the chemical composition after processing, and the samples were mechanically investigated via Vickers micro-hardness testing. Findings A combination of process parameters resulting in an energy density value of 1.011 J/mm2 allowed the successful production of components directly from Lunar regolith simulant. An internal relative porosity of 40.8 per cent, material hardness of 670 ± 11 HV and a dimensional accuracy of 99.8 per cent were observed in the fabricated samples. Originality/value This research paper is investigating the novel application of a powder bed fusion AM process category as a potential on-site manufacturing approach for manufacturing structures/components out of Lunar regolith (Moondust). It was shown that this AM process category has the capability to directly manufacture multi-layered parts out of Lunar regolith, which has potential applicability to future moon colonization.

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