Low-cost automatic system for the control of the surface quality of coated and uncoated wafers

Author(s):  
Alexandre Joerg ◽  
Julien H. Lumeau ◽  
Myriam Zerrad ◽  
Michel Lequime
2010 ◽  
Vol 113-116 ◽  
pp. 508-511 ◽  
Author(s):  
Wei Liang Zeng ◽  
Yan Ling Guo

According to its advantages, such as low-cost and green biological etc., Wood-Plastic Composite(WPC) is more suitable for make parts by Selective Laser Sintering(SLS) rapid prototyping (RP) process. With optimal design of components, the parts made by WPC have good mechanical properties as well as with good laser sintering properties. In order to further improve the surface quality of the parts, the post-processing–infiltrating with wax–is introduced. After post-processing, the void fraction is decreased from 51% to 7%, surface quality has been greatly improved, Ra belows 13µm on average, after polishing the surface is more smooth and Ra belows 5µm averagely,compared to those without post processing, surface roughness decrease 22% and 73% respectively.


Author(s):  
Xiangjia Li ◽  
Huachao Mao ◽  
Yayue Pan ◽  
Yong Chen

The mask image projection-based stereolithography (MIP-SL) is a low-cost and high-resolution additive manufacturing (AM) process. However, the slow speed of part separation and resin refilling is the primary bottleneck that limits the fabrication speed of the MIP-SL process. In addition, the stair-stepping effect due to the layer-based fabrication process limits the surface quality of built parts. To address the critical issues in the MIP-SL process related to resin refilling and layer-based fabrication, we present a mask video projection-based stereolithography (MVP-SL) process with continuous resin flow and light exposure. The newly developed AM process enables the continuous fabrication of three-dimensional (3D) objects with ultra-high fabrication speed. In the paper, the system design to achieve mask video projection and the process settings to achieve ultrafast fabrication speed are presented. The relationship between process parameters and the surface quality of the built parts is discussed. Test results illustrate that the MVP-SL process with a continuous resin flow can build three-dimensional objects within minutes, and the surface quality of the fabricated objects is significantly improved.


2019 ◽  
Vol 12 (3) ◽  
pp. 201-210
Author(s):  
Yuan Li ◽  
Ye Dai ◽  
Yunshan Qi ◽  
Yufei Gao

Background: Mechanical parts in processing and manufacturing process will produce burr, scratches and other surface quality problems, which have adverse effects on the precision, use, reprocessing location, operation safety and appearance quality of the parts, so it is necessary to grind the workpiece surface. Objective: Based on the recent development in the field of magnetic grinding and related patent research, it can provide reliable help to solve the problem of finishing the surface of parts with complex shapes and small volumes. Methods: This paper reviewed some patents and research advances related to magnetic abrasive finishing, and the advantages and disadvantages of the magnetic grinding machine in the finishing process were summarized. The outstanding grinding effect of the new vibration assisted magnetic grinder was introduced. Results: The working characteristics of various magnetic grinding machines were summarized, and the development trend of magnetic grinding and finishing was prospected. Conclusion: Magnetic abrasive finishing has good flexibility, strong self-sharpening, wide applicable scope, high processing efficiency, simple processing equipment and low cost. It can control the grinding efficiency and grinding precision. The machining efficiency and quality of magnetic grinding can be improved with the appropriate amplitude of vibration assist, and the surface quality can be improved significantly.


2012 ◽  
Vol 532-533 ◽  
pp. 390-393 ◽  
Author(s):  
Jian Chuan Zhang ◽  
Wu Bin Li ◽  
Chang Hou Lu

To inspect the surface quality of steel bar, we designed an automatic system including linear camera and laser. Through the comparison among kinds of cameras, we select linear CCD to our system. The laser is also chosen by us with its high luminance and performance. Through a series of computation, we select the appropriate camera lens to our device. At last, we draw the whole detection system. This device has been used well and provides a good foundation for prospective image processing.


Author(s):  
Xiangjia Li ◽  
Huachao Mao ◽  
Yayue Pan ◽  
Yong Chen

The mask image projection based stereolithography (MIP-SL) is a low cost and high-resolution additive manufacturing (AM) process. However, the slow speed of part separation and resin refilling is the primary bottleneck that limits the fabrication speed of the MIP-SL process. In addition, the stair steeping effect due to the layer-based fabrication process limits the surface quality of built parts. To address the critical issues in the MIP-SL process related to resin refilling and layer-based fabrication, we present a mask video projection based stereolithography (MVP-SL) process with continuous resin flow and light exposure. The newly developed AM process enables the continuous fabrication of three-dimensional (3D) objects with ultra-high fabrication speed. In the paper. The system design to achieve mask video projection and the process settings to achieve ultrafast fabrication speed are presented. The relationship between process parameters and the surface quality of the fabricated parts is discussed. Test results illustrate the MVP-SL process with continuous resin flow can build three-dimensional objects within minutes and the surface quality of the fabricated objects can be significantly improved.


2013 ◽  
Vol 20 (3) ◽  
pp. 91-106 ◽  
Author(s):  
Rachel Pizarek ◽  
Valeriy Shafiro ◽  
Patricia McCarthy

Computerized auditory training (CAT) is a convenient, low-cost approach to improving communication of individuals with hearing loss or other communicative disorders. A number of CAT programs are being marketed to patients and audiologists. The present literature review is an examination of evidence for the effectiveness of CAT in improving speech perception in adults with hearing impairments. Six current CAT programs, used in 9 published studies, were reviewed. In all 9 studies, some benefit of CAT for speech perception was demonstrated. Although these results are encouraging, the overall quality of available evidence remains low, and many programs currently on the market have not yet been evaluated. Thus, caution is needed when selecting CAT programs for specific patients. It is hoped that future researchers will (a) examine a greater number of CAT programs using more rigorous experimental designs, (b) determine which program features and training regimens are most effective, and (c) indicate which patients may benefit from CAT the most.


2020 ◽  
Vol 110 (11-12) ◽  
pp. 838-843
Author(s):  
Philipp Müller ◽  
Bernd-Arno Behrens ◽  
Sven Hübner ◽  
Hendrik Vogt ◽  
Daniel Rosenbusch ◽  
...  

Techniken zur Steigerung der Formgebungsgrenzen in der Umformtechnik sind von hoher wirtschaftlicher Bedeutung. In dieser Arbeit wird eine Schwingungsüberlagerung im Krafthauptfluss eines Axialformprozesses zur Ausprägung einer Verzahnungsgeometrie untersucht. Die Auswirkungen der Schwingung auf die erzielbare Ausfüllung der Zahnkavitäten werden analysiert sowie die Parameter Schmierung und Oberflächengüte der Halbzeuge in ihrer kombinierten Wirkung untersucht. Es konnte eine Reduzierung der mittleren Umformkraft sowie eine Erhöhung der Formfüllung festgestellt werden. Techniques for extending the production limits in forming technology are of great economic importance. In this research, a superimposed oscillation in the main force flow of an axial forming process to form an axial gear geometry is investigated. The effects of the superimposed oscillation on the achievable form-filling of the tooth cavities are analyzed and the parameters lubrication and surface quality of the semi-finished products are investigated in their combined effect. A reduction of the averaged forming force as well as an increase of the form-filling could be achieved.


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