Imaging quality 3D-printed inch scale lenses with 10[angstrom] surface quality for swift small or medium volume production (Conference Presentation)

2019 ◽  
Author(s):  
Bisrat Girma Assefa ◽  
Henri Partanen ◽  
Markku Pekkarinen ◽  
Joris Biskop ◽  
Jari Turunen ◽  
...  
Keyword(s):  
Surface Quality ◽  
Imaging Quality ◽  
Volume Production ◽  
3D Printed

Influence of slicing parameters on surface quality and mechanical properties of 3D-printed CF/PLA composites fabricated by FDM technique

2021 ◽  
pp. 1-18
Author(s):  
N. Vinoth Babu ◽  
N. Venkateshwaran ◽  
N. Rajini ◽  
Sikiru Oluwarotimi Ismail ◽  
Faruq Mohammad ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surface Quality ◽  
3D Printed

Rapid surface quality assessment of green 3D printed metal-binder parts

2019 ◽  
Vol 38 ◽  
pp. 290-297 ◽  
Author(s):  
Kedarnath Rane ◽  
Kevin Castelli ◽  
Matteo Strano
Keyword(s):  
Quality Assessment ◽  
Surface Quality ◽  
Metal Binder ◽  
3D Printed

scholarly journals Imaging-quality 3D-printed centimeter-scale lens

2019 ◽  
Vol 27 (9) ◽  
pp. 12630 ◽  
Author(s):  
Bisrat G. Assefa ◽  
Markku Pekkarinen ◽  
Henri Partanen ◽  
Joris Biskop ◽  
Jari Turunen ◽  
...  
Keyword(s):  
Imaging Quality ◽  
3D Printed

Design and Manufacturing of a Metal 3D Printed kW Scale Axial Turboexpander

2019 ◽  
Author(s):  
Vaclav Novotny ◽  
Monika Vitvarova ◽  
Michal Kolovratnik ◽  
Barbora Bryksi Stunova ◽  
Vaclav Vodicka ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Surface Quality ◽  
High Efficiency ◽  
Cost Effective ◽  
Manufacturing Cost ◽  
Machining Processes ◽  
Manufacturing Method ◽  
Design And Manufacturing ◽  
3D Printed

Abstract Greater expansion of distributed power and process systems based on thermodynamic cycles with single to hundred kW scale power output is limited mainly there are not available cost-effective expanders. Turboexpanders have a perspective of high efficiency and flexibility concerning operating parameters even for the micro applications. However, they suffer from a high manufacturing cost and lead time in the development of traditional technologies (such as casting and machining processes). Additive manufacturing provides a possibility to overcome some of the issues. Manufacturing parts with complicated shapes by this technology, combining multiple components into a single part or rapid production by 3D printing for development purposes are among the prospective features with this potential. On the other hand, the 3D printing processes come with certain limitations which need to be overcome. This paper shows a design and manufacturing process of a 3 kW axial impulse air turbine working with isenthalpic drop 30 kJ/kg. Several samples to verify printing options and the turbine itself has been manufactured from stainless steel by the DMLS additive manufacturing method. Manufactured are two turbine variations regarding blade size and 3D printer settings while maintaining their specific dimensions. The turboexpanders testing method and rig is outlined. As the surface quality is an issue, several methods of post-processing of 3D printed stator and rotor blading to modify surface quality are suggested. Detailed experimental investigation is however subject of future work.

Development of Laser Polishing As an Auxiliary Post-Process to Improve Surface Quality in Fused Deposition Modeling Parts

2017 ◽  
Author(s):  
Mario Perez Dewey ◽  
Durul Ulutan
Keyword(s):  
Surface Quality ◽  
Fused Deposition Modeling ◽  
Thin Layers ◽  
Process Time ◽  
Laser Polishing ◽  
Fused Deposition ◽  
Post Process ◽  
Deposition Modeling ◽  
3D Printed ◽  
Plastic Parts

Laser polishing is a highly effective surface treatment process mainly used on metals and optical components, but it can also be used on plastic parts. It requires no manual labor, can be applied on parts of any size, and produces no hazardous or polluting substances on many plastic parts. Fused deposition modeling (FDM) is an additive manufacturing process in which parts are built by extruding thin layers of hot material through a nozzle. It has the advantage of producing complicated part geometries, and the possibility to change a design with no additional cost. This study investigates the use of laser polishing as an auxiliary post-process on Polylactic Acid (PLA) parts produced with FDM to improve the surface quality of final products. Although YAG lasers are commonly used in assisting metal machining processes, a CO2 laser was utilized in this study to post-process 3D-printed parts in order to reduce the staircase appearance. The main purpose of this study is to demonstrate that instead of reducing step size in 3D printing processes, it is possible to use bigger step sizes and laser treat the surface quickly afterwards to decrease the total process time while not compromising from surface quality. Laser speeds of 43–180 mm/s and laser powers of 0.75–3.75 W were tested on blocks of 3D-printed PLA with a parallelogram prism shape at 0.3 mm layer height. By varying laser speed and power, roughness reductions of up to 97% were achieved resulting in a uniform average surface roughness of 2.02 μm. This presents a fast, automatable, and inexpensive auxiliary post-process to FDM.

scholarly journals Surface Finishing of FDM-Fabricated Amorphous Polyetheretherketone and Its Carbon-Fiber-Reinforced Composite by Dry Milling

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2175
Author(s):  
Cheng Guo ◽  
Xiaohua Liu ◽  
Guang Liu
Keyword(s):  
Carbon Fiber ◽  
Layer Thickness ◽  
Surface Quality ◽  
Feed Rate ◽  
Depth Of Cut ◽  
Dry Milling ◽  
Staircase Effect ◽  
Raster Angle ◽  
3D Printed

In recent years, many investigations have been devoted to fused deposition modeling (FDM) of high-performance polymer-polyetheretherketone (PEEK) and carbon-fiber-reinforced PEEK (CF/PEEK) for biomedical and aerospace applications. However, the staircase effect naturally brought about by FDM restricts further applications of 3D-printed PEEK and its composites in high-temperature molds, medical implants, and precision components, which require better or customized surface qualities. Hence, this work aimed to reduce the staircase effect and improve the surface quality of 3D-printed PEEK and CF/PEEK parts by dry milling of the fluctuant exterior surface. The co-dependency between 3D printing parameters (raster angle and layer thickness) and milling parameters (depth of cut, spindle speed, and feed rate per tooth) were investigated through experiments. The difference in removal mechanisms for PEEK and CF/PEEK was revealed. It was confirmed that the smearing effect enhanced the surface quality based on the morphology analysis and the simulation model. Both the raster angle of +45°/−45° and the small layer thickness could improve the surface quality of these 3D-printed polymers after dry milling. A large depth of cut and a large feed rate per tooth were likely to deteriorate the finished polymer surface. The spindle speed could influence the morphologies without significant changes in roughness values. Finally, a demonstration was performed to verify that dry milling of 3D-printed amorphous PEEK and CF/PEEK parts could lead to a high surface quality for critical requirements.

scholarly journals Sliding behaviour and surface quality after static air polishing of conventional and modern bracket materials

2021 ◽  
Author(s):  
Lutz Hodecker ◽  
Christoph Bourauel ◽  
Bert Braumann ◽  
Teresa Kruse ◽  
Hildegard Christ ◽  
...  
Keyword(s):  
Surface Quality ◽  
Structural Defects ◽  
Dental Calculus ◽  
Air Polishing ◽  
Tooth Cleaning ◽  
Effective Reduction ◽  
Noticeable Improvement ◽  
Ceramic Brackets ◽  
3D Printed

Abstract Objectives As part of orthodontic treatment, air polishing is routinely used for professional tooth cleaning. Thus, we investigated the effects of static powder polishing on sliding behaviour and surface quality of three different bracket materials (polymer, ceramic, metal), including a 3D-printed bracket. Methods Two bracket types of each material group were polished with an air-polishing device using sodium bicarbonate. Exposure times were set at 10, 20, and 60 s; the application distance was 5 mm. The force loss due to sliding resistance was tested with an orthodontic measurement and simulation system (OMSS) using a 0.016 inch × 0.022 inch stainless steel archwire. Untreated brackets served as control. Polishing effects and slot precision were evaluated using an optical digital and scanning electron microscope. Results Sliding behaviour and slot precision differed significantly between and within the groups. Prior to polishing, polymer brackets showed the least force loss, ceramic brackets the highest. With progressive polishing time, the resistance increased significantly with titanium brackets (26 to 37%) and decreased significantly with steel brackets (36 to 25%). Polymer brackets showed the smallest changes in force loss with respect to polishing duration. Slot precision showed the largest differences between material groups and was primarily manufacturer-dependent with hardly any changes due to the polishing time. Conclusion Powder polishing can positively or negatively affect the sliding properties of the bracket–archwire complex but is more dependent on the bracket–archwire material combination (i.e., manufacture-dependent slot precision). For titanium brackets, resistance only increased after 60 s of polishing. For ceramic brackets, effective reduction was observed after 10 s of polishing. Polymer brackets, including the 3D-printed brackets, showed better sliding properties than ceramic or metal brackets even after polishing for 60 s. Removal of plaque and dental calculus should lead to a noticeable improvement of the sliding properties and outweighs structural defects that may develop.

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