scholarly journals EXPERIMENT PLAN FOR RESEARCHES OF POLISHING PROCESS OF OPTICAL DETAILS / OPTINIŲ DETALIŲ POLIRAVIMO PROCESO EKSPERIMENTINIO TYRIMO PLANAVIMAS

2017 ◽  
Vol 8 (6) ◽  
pp. 563-566
Author(s):  
Ieva Švagždytė ◽  
Mindaugas Jurevičius
Keyword(s):  
Experimental Data ◽  
Optical Glass ◽  
Polishing Process ◽  
High Quality ◽  
Quality Requirements ◽  
Multicriterion Optimization

Descriptions of polishing process, using technologies, materials of optical details are given in this article. High quality requirements are raising for optical details – smoothness of surface, non-existence of effects, form deflections, which are obtainable in polishing process. Results of modelling and experimental data are given in published scientist researches; various cutting rates were used in polishing process. Experiment plan for polishing plane details from optical glass BK7 with different cutting rates is given in this article. Multicriterion optimization in polishing process using for high quality optical details. Straipsnyje aprašomas optinių detalių poliravimo procesas, naudojamosios technologijos ir medžiagos. Optinėms detalėms keliami aukšti tikslumo reikalavimai – paviršiaus glotnumo, defektų nebuvimo, formos nuokrypių ir kt., jie gau­nami poliravimo proceso metu. Mokslininkų paskelbtuose tyrimuose pateikiami modeliavimo rezultatai, gauti eksperimentų metu, tirtos įvairios apdirbamosios medžiagos, jų paviršiaus kokybė, poliruota įvairiais pjovimo režimais. Šiame straipsnyje aprašomas eksperimento planas, skirtas plokščioms detalėms iš optinio stiklo BK7 poliruoti, kai varijuojama keliais apdirbimo režimais. Siekiama gauti aukštą gaminių kokybę daugiakriterio optimizavimo būdu.

scholarly journals Development of a New Finishing Process Combining a Fixed Abrasive Polishing with Magnetic Abrasive Finishing Process

Machines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 81
Author(s):  
Yanhua Zou ◽  
Ryunosuke Satou ◽  
Ozora Yamazaki ◽  
Huijun Xie
Keyword(s):  
Alumina Ceramic ◽  
Ceramic Plate ◽  
Polishing Process ◽  
High Quality ◽  
Influence Of Process Parameters ◽  
Magnetic Abrasive Finishing ◽  
Nano Scale ◽  
Finishing Process ◽  
Abrasive Finishing ◽  
Fixed Abrasive

High quality, highly efficient finishing processes are required for finishing difficult-to-machine materials. Magnetic abrasive finishing (MAF) process is a finishing method that can obtain a high accuracy surface using fine magnetic particles and abrasive particles, but has poor finishing efficiency. On the contrary, fixed abrasive polishing (FAP) is a polishing process can obtain high material removal efficiency but often cannot provide a high-quality surface at the nano-scale. Therefore, this work proposes a new finishing process, which combines the magnetic abrasive finishing process and the fixed abrasive polishing process (MAF-FAP). To verify the proposed methodology, a finishing device was developed and finishing experiments on alumina ceramic plates were performed. Furthermore, the mechanism of the MAF-FAP process was investigated. In addition, the influence of process parameters on finishing characteristics is discussed. According to the experimental results, this process can achieve high-efficiency finishing of brittle hard materials (alumina ceramics) and can obtain nano-scale surfaces. The surface roughness of the alumina ceramic plate is improved from 202.11 nm Ra to 3.67 nm Ra within 30 min.

Thermal Laser Separation – A Novel Dicing Technology Fulfilling the Demands of Volume Manufacturing of 4H-SiC Devices

2015 ◽  
Vol 821-823 ◽  
pp. 528-532 ◽  
Author(s):  
Dirk Lewke ◽  
Karl Otto Dohnke ◽  
Hans Ulrich Zühlke ◽  
Mercedes Cerezuela Barret ◽  
Martin Schellenberger ◽  
...  
Keyword(s):  
Experimental Data ◽  
Process Control ◽  
Tool Wear ◽  
Large Scale ◽  
State Of The Art ◽  
Scale Production ◽  
High Quality ◽  
Large Scale Production ◽  
Laser Separation

One challenge for volume manufacturing of 4H-SiC devices is the state-of-the-art wafer dicing technology – the mechanical blade dicing which suffers from high tool wear and low feed rates. In this paper we discuss Thermal Laser Separation (TLS) as a novel dicing technology for large scale production of SiC devices. We compare the latest TLS experimental data resulting from fully processed 4H-SiC wafers with results obtained by mechanical dicing technology. Especially typical product relevant features like process control monitoring (PCM) structures and backside metallization, quality of diced SiC-devices as well as productivity are considered. It could be shown that with feed rates up to two orders of magnitude higher than state-of-the-art, no tool wear and high quality of diced chips, TLS has a very promising potential to fulfill the demands of volume manufacturing of 4H-SiC devices.

scholarly journals Analysis on the Conformity between the Closed-Circuit Embroidery Elements of Different Widths and the Digitally Designed Elements

2019 ◽  
Vol 19 (3) ◽  
pp. 250-256
Author(s):  
Žaneta Juchnevičienė ◽  
Milda Jucienė ◽  
Vaida Dobilaitė ◽  
Virginija Sacevičienė ◽  
Svetlana Radavičienė
Keyword(s):  
Closed Circuit ◽  
Dynamic Loads ◽  
Geometrical Parameters ◽  
High Quality ◽  
Quality Requirements ◽  
Textile Materials ◽  
The Creation

Abstract The embroidery process is one of the means of joining textile materials into a system, which is widely applied in the creation of products of special destinations. The development of the functionality of embroidery systems is indissoluble from high-quality requirements for the accuracy of the form of the element. In the embroidery process, the system of textile materials experiences various dynamic loads, multiple stretching, and crushing; therefore, the geometrical parameters of the embroidery element change. The objective of this paper was to analyze the widths of the different square-form closed-circuit embroidery elements and also to perform their analysis with the purpose to evaluate the embroidery accuracy of the embroidered elements. Test samples were prepared in the form of square-form closed-circuit embroidery elements of five different contour widths: 6 mm, 10 mm, 14 mm, 18 mm, and 22 mm. During the investigation, it has been determined that in most cases the contour widths of the five closed-circuit square-form embroidery elements were obtained, smaller than the size of the digitally designed element.

scholarly journals IMPROVING WATERPROOFING PROPERTIES IN THE WALL BASEMENT AREA BY INJECTION METHOD

2019 ◽  
Vol 2 (53) ◽  
pp. 122-127
Author(s):  
Olena Filonenko ◽  
Maryna Leshchenko ◽  
Olesia Rozdabara ◽  
Oleksandr Duka ◽  
Vlad Pashchenko ◽  
...  
Keyword(s):  
Experimental Data ◽  
Moisture Content ◽  
Experimental Research ◽  
High Quality ◽  
Injection Method ◽  
Wall Area

The article is focused on the natural experimental research of injection waterproofing impact on basement areas of existingbuildings brick walls. Two types of experimental installations for waterproofing material injection have been developed. Thesecond type turned out to be more efficient due to the fact that it could cover larger waterproofing wall area. It can possiblyspeed up the process of walls waterproofing and major repairs of buildings in general. According to the experimental data, after the injection waterproofing placement, the wall moisture content decreased by half due to the high quality waterproofingmaterial and performed installation work.

Research on Diamond Polishing Process Based on Rough Set

2011 ◽  
Vol 295-297 ◽  
pp. 1856-1859 ◽  
Author(s):  
Yong Tao Ma ◽  
Ye Ma
Keyword(s):  
Experimental Data ◽  
Rough Set ◽  
Engineering Application ◽  
Load Factor ◽  
Hot Metal ◽  
Polishing Process ◽  
Iron Metal ◽  
Diamond Polishing ◽  
The Relationship

Polishing diamond with hot metal method was hard to get experimental data, which was very important to the process of polishing. The relationship between polishing parameters and polishing quantity cannot be easily deduced with the limited experimental data. This paper uses Rough Set method to process the data and some useful conclusions have been drawn. The load factor in polishing process can be ignored in the polishing process. In the case of engineering application, the load merely ensures the contact between diamond and hot iron metal. Other parameters, such as temperature, polishing speed and time, are important factors to the polishing quality.

Study on Dual-Plane Ball Polishing Method for Finishing Ceramics Ball

2013 ◽  
Vol 797 ◽  
pp. 444-449 ◽  
Author(s):  
Kai Ping Feng ◽  
Zhao Zhong Zhou ◽  
Bing Hai Lv ◽  
Ju Long Yuan
Keyword(s):  
Surface Roughness ◽  
Process Parameters ◽  
Mechanical Damage ◽  
Lower Plate ◽  
Mathematics Model ◽  
Polishing Process ◽  
High Quality ◽  
Dual Plane ◽  
Surface Polishing ◽  
Polishing Machine

This paper represents a dual-plane polishing method for ceramics ball. Compared with traditional ball polishing method, its upper and lower plate are all flat and easy to use soft pad to polish, so it can largely reduce the surface mechanical damage and obtain high quality processing surface. This paper analyzes surface polishing trajectory by calculation and simulation to test the polishing trajectory uniformity. A mathematics model of polishing process is established to disintegrate the process of a balls movement. Experiment is operated in dual-plane planetary polishing machine. The result shows that perfect polishing surface and spherical error can be obtained under the proper process parameters, the surface roughness achieves 4nm and the spherical error can reach 0.217μm.

Quality-Oriented IT Service Management

2011 ◽  
pp. 108-123
Author(s):  
Patrick Wild
Keyword(s):  
Service Quality ◽  
Service Provider ◽  
Service Management ◽  
Service Providers ◽  
It Services ◽  
Quality Model ◽  
High Quality ◽  
Quality Requirements ◽  
Reference Models ◽  
It Service

<div>Due to the increasing importance of the tertiary sector, information technology (IT) organizations need to face up to new challenges, since their daily business has changed from development and operation of information technology to the customer oriented provision and management of IT services. In order to survive in the market, service providers need to offer and manage competitive and distinctive IT services. The “Profit Impact of Market Strategies” (PIMS) program has emphasized the need for service quality as being a crucial, strategic competitive factor. However, IT service providers do not have guidance of what quality requirements are supposed to be fulfilled to provide high-quality IT services. Different reference models and frameworks such as ITIL (Information Technology Infrastructure Library), COBIT (Control Objectives for Information and related Technology) and ISO 20000 are widely used by many IT organizations for improving service management processes and performance. However, these reference models do not address the improvement of service quality in a consistent manner and it is not clear whether these models have the capability to close quality gaps which may arise within a service provider environment.</div><div><br></div><div>Therefore, this chapter proposes an IT service quality model for identifying potential quality&nbsp;gaps and quality dimensions in an IT service provider environment. Furthermore, it proposes a set of different quality requirements combined in a “Quality Requirements Model for IT Services” that are needed in order to close the respective quality gaps and fulfill the individual quality dimensions. The model is developed by mapping&nbsp;the reference models ITIL v3, COBIT and ISO 20000 to the previously developed quality model. The results of the mappings emphasize that all three models are partially capable to close the individual gaps of the quality model as well as to guarantee the fulfillment of respective quality dimensions. The fulfillment of these developed quality requirements can be utilized as a guideline for providing and managing high-quality IT services in the long term.</div><div><br></div><div>Finally, the maturity level is analyzed and pointed out that most of the quality requirements are assigned to maturity stage 2 or 3. This implies that an IT service provider does not necessarily have to reach a maturity stage 4 or 5 being able offering high service quality.</div><div><br></div><div>In summary, the chapter provides guidance and quality-oriented IT Service Management to answer the following questions:</div><div><br></div><div><ul><li>What kind of quality gaps exist in a service provider environment?<br></li><li>Do reference models such as ITIL, COBIT and ISO 20000 have the capability to close quality gaps which may arise within a service provider environment?<br></li><li>What processes, activities and functions from which reference model are needed in order to close the respective gaps?<br></li><li>What quality requirements need to be implemented in order to provide high-quality IT services?<br></li><li>What maturity level do service providers need to reach in order to fulfill quality requirements?<br></li></ul></div>

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.

scholarly journals Morphological Characteristics of Dimples of Ductile Fracture of VT23M Titanium Alloy and Identification of Dimples on Fractograms of Different Scale

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2051 ◽  
Author(s):  
Ihor Konovalenko ◽  
Pavlo Maruschak ◽  
Janette Brezinová ◽  
Jozef Brezina
Keyword(s):  
Titanium Alloy ◽  
Ductile Fracture ◽  
Digital Images ◽  
Morphological Characteristics ◽  
Automated Detection ◽  
Fracture Mechanisms ◽  
Test Results ◽  
High Quality ◽  
Quality Requirements ◽  
Shape And Size

The authors developed a method for the automated detection and calculation of quantitative parameters of dimples of ductile fracture on the digital images of fracture surfaces obtained at different scales. The processing algorithm of fractographic images was proposed, which allowed high quality recognition of the shape and size of dimples to be achieved, taking into account the morphological features of their digital images. The developed method for identifying dimples of various physical and morphological characteristics was tested on the VT23M alloy. The test results showed that the method meets the quality requirements for the automated diagnostics of fracture mechanisms of titanium alloys.

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