scholarly journals Research to Evaluate the Effectiveness of the Diamond Disc for Grinding the Granite Surface

2019 ◽  
Vol 603 ◽  
pp. 042078
Author(s):  
Marlena Rajczyk ◽  
Pawel Rajczyk
Keyword(s):  
Diamond Disc

scholarly journals METHOD OF SELECTING THE OPERATION PARAMETERS OF ELECTRIC SPINDLE WITH AEROSTATIC SUPPORTS FOR SEPARATION OF SEMICONDUCTOR PLATES TO CRYSTALS. PARTS 2–3

2021 ◽  
Vol 3 (56) ◽  
pp. 25-41
Author(s):  
Alexander E. KOVENSKY ◽  
◽  
Vladimir L. BASINIUK ◽  
Ryta E. VOLKOTRUB ◽  
◽  
...  
Keyword(s):  
Rotational Speed ◽  
High Speed ◽  
Resonant Mode ◽  
Forced Oscillations ◽  
Diamond Cutting ◽  
Spindle Shaft ◽  
Operation Parameters ◽  
Main Components ◽  
Full Scale Tests ◽  
Diamond Disc

The article presents the results of studies of the shaft oscillation processes of a precision horizontal highspeed electric spindle with aerostatic radial and axial supports, used at Planar OJSC in equipment for separation of semiconductor plates into crystals. The studies were carried out using the developed mathematical models that take into account the design features of these electric spindles, including the cantilever mounting of the cutting tool, the imbalance of the diamond disc with the mandrel and the mass ratio of the main components of the electric spindle, as well as the results of their full-scale tests. Based on the analysis of the data obtained, regularities are shown that connect the amplitude values of the oscillations of the electric spindle shaft with the imbalance of the diamond disc with the mandrel and the rotational speed of the electric spindle, which made it possible to propose engineering dependences for choosing the permissible values of the imbalance and rational, from the standpoint of resonance conditions and permissible shaft oscillations, rotational speed of the electric spindle. Recommendations have been developed for the creation of a system for monitoring and active control of the parameters and functioning of the electric spindle in the process of separating semiconductor plates into crystals, which make it possible to use the resonant mode of radial oscillations to improve cutting conditions, excluding direct contact of the working surfaces of aerostatic supports, their seizure and loss of performance of the electric spindle. The article presents a method of selecting the operation parameters of a high-speed precision horizontal electric spindle with aerostatic radial and axial supports and a cantilever mounting of a diamond cutting disc. It is based on the analysis of the simulation results of shaft forced oscillations and data on the shaft oscillations during the operation of the electric spindle with different rotation frequencies and imbalances. The results obtained can be used to monitor shaft oscillations during the operation of the electric spindle, while the high operation efficiency of which is achieved by adaptive control of rotation frequencies taking into account the amplitudes of these oscillations.

scholarly journals Efficiency increase in combined electro-chemical grinding of hard alloys by diamond metal bonded disks

2017 ◽  
Vol 2 (2) ◽  
pp. 3-8
Author(s):  
Ольга Медведева ◽  
Olga Medvedeva ◽  
Александр Янюшкин ◽  
Aleksandr Yanyushkin ◽  
Павел Архипов ◽  
...  
Keyword(s):  
Theoretical Models ◽  
Capacity Factor ◽  
Hard Alloys ◽  
Metal Bond ◽  
Disc Cutting ◽  
Efficiency Increase ◽  
The Stability ◽  
Cutting Capacity ◽  
Diamond Disc

In the paper there are emphasized problems connected with the use of diamond metal bond abrasive discs at the processing of hard alloys. The reasons of cutting capacity decrease are pointed out which limit a wide-spread use of a diamond metal bond tool. It is established that for the achievement of a required productivity and quality of ready products is possible at the expense of the application of electro-chemical and electro-physical methods of stropping and also due to the improvement of abrasive disc designs. This work reports the investigations of a cutting capacity of diamond discs at the working of hard alloys by a combined method of electro-chemical grinding with simultaneous continuous stropping. As an output parameter there was accepted a cutting capacity factor of a diamond which was assesses according to the changes in effective working capacity. On the basis of the results of the experimental data processed there were obtained theoretical models of the dependence of the cutting capacity factor upon electric and mechanical constituents of the modes of combined electro-chemical grinding. A complex of investigations directed to the detection of efficient modes ensuring the stability of cutting capacity in diamond metal bond discs is carried out. It is experimentally confirmed that the application of the method of combined electro-chemical grinding with the simultaneous continuous disc stropping at working hard alloy materials allows increasing diamond disc cutting capacity by 15% in comparison with other methods of the diamond working of such materials.

scholarly journals Bond strength to dentin of total-etch and self-etch adhesive systems

2014 ◽  
Vol 62 (4) ◽  
pp. 365-370 ◽  
Author(s):  
Ricardo Alves dos SANTOS ◽  
Eliane Alves de LIMA ◽  
Mônica Maria de Albuquerque PONTES ◽  
Alexandre Batista Lopes do NASCIMENTO ◽  
Marcos Antônio Japiassú Resende MONTES ◽  
...  
Keyword(s):  
Bond Strength ◽  
Testing Machine ◽  
Adhesive System ◽  
Single Bond ◽  
Adhesive Systems ◽  
Healthy Human ◽  
Universal Testing ◽  
Stereo Microscope ◽  
Diamond Disc ◽  
Self Etch

OBJECTIVE: To assess the bond strength to dentin of the Single Bond (3M ESPE) and XP Bond (Dentsply) total-etch and Adper SE Plus (3M ESPE) self-etch adhesive systems. METHODS: Fifteen healthy human third molars were randomly allocated across three different groups of five teeth each according to the adhesive system. The occlusal portion of each tooth was removed under refrigeration using a flexible diamond disc (EXTEC, Enfield, CT, USA) down to an area of dentin that did not reveal enamel, as confirmed under a 40X stereo microscope (Ramsor, São Paulo, Brazil). A standardized smear layer was created with #600 grit silicon-carbide paper. The adhesive systems were applied as per manufacturer recommendations, with the exception of the Adper SE Plus system, which was triple-polymerized. Composite resin blocks (5 mm) were placed on the dentin surface. The specimens were stored in distilled water for 24 hours at 37ºC. Using a flexible diamond disc (EXTEC, Enfield, CT, USA), toothpick-like specimens with an adhesive area of less than 1 mm² were obtained. A microtensile bond test was then carried out using a universal testing machine (KRATOS) with a crosshead speed of 0.5 mm/min. Analysis of variance (ANOVA) and Tukey's test were used for comparisons. RESULTS: The bond strength values obtained with each adhesive system were as follows: XP Bond, 96.24 MPa; Adper Single Bond, 72.39 MPa; Adper SE Plus, 49.91 MPa. CONCLUSION: In terms of bond strength to dentin, conventional adhesives outperform self-etching systems.

Finite Element Modeling of Pad Deformation due to Diamond Disc Conditioning in Chemical Mechanical Polishing (CMP)

2012 ◽  
Author(s):  
Emmanuel A. Baisie ◽  
Z. C. Li ◽  
X. H. Zhang
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Material Removal ◽  
High Performance ◽  
Removal Rate ◽  
Chemical Mechanical Planarization ◽  
Element Analysis ◽  
Fea Model ◽  
Pad Wear ◽  
Diamond Disc

Chemical mechanical planarization (CMP) is widely used to planarize and smooth the surface of semiconductor wafers. In CMP, diamond disc conditioning is traditionally employed to restore pad planarity and surface asperity. Pad deformation which occurs during conditioning affects the material removal mechanism of CMP since pad shape, stress and strain are related to cut rate during conditioning, pad wear rate and wafer material removal rate (MRR) during polishing. Available reports concerning the effect of diamond disc conditioning on pad deformation are based on simplified models of the pad and do not consider its microstructure. In this study, a two-dimensional (2-D) finite element analysis (FEA) model is proposed to analyze the interaction between the diamond disc conditioner and the polishing pad. To enhance modeling fidelity, image processing is utilized to characterize the morphological and mechanical properties of the pad. An FEA model of the characterized pad is developed and utilized to study the effects of process parameters (conditioning pressure and pad stiffness) on pad deformation. The study reveals that understanding the morphological and mechanical properties of CMP pads is important to the design of high performance pads.

scholarly journals Prevalence of Different Types of Apical Root Canal Morphology and their Treatment Recommendations in an Institute

2018 ◽  
Vol 56 (210) ◽  
pp. 616-620 ◽  
Author(s):  
Sushmita Shrestha ◽  
Smriti Karki ◽  
Navin Agrawal ◽  
Mannu Vikram ◽  
Vimmi Singh ◽  
...  
Keyword(s):  
Root Canal ◽  
Sampling Technique ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Root Canals ◽  
Rotary Instruments ◽  
Root Canal Morphology ◽  
Different Shapes ◽  
Diamond Disc

  Introduction: Canals can be of different shapes in cross section including round canals, oval canals, long oval canals or ribbon shaped canals. Recesses of nonround canals may not be included in the round preparation created by rotary instruments and thus they remain unprepared. The aim of this study included determination of shape and taper of the apical root canal based on diameter at different levels. Methods: This was a cross sectional study which used convenient sampling technique to determine the sample size. Seventy extracted teeth were sectioned horizontally at one, two and three millimeter from the apex using the diamond disc which was observed under trinocular research microscope for the determination of diameter of root canal under 10x magnification. Results: The most common canal configuration was oval. The taper of the canals was 25% in mesial root and 20% in distal in bucco-lingual orientation and 14% in mesial root and 15% in distal in mesio-distal orientation. Conclusions: The most prevalent canal configuration in this study was non round, however, most of the rotary instruments tend to prepare root canals into round shape making their use questionable. The taper of the root canals was found to be higher in our study than what most of the shaping instruments have to offer. So it would be advisable to consider this fact while selecting instruments and preparing these non-round canals as far as the Nepalese subpopulation is considered.

scholarly journals THE INFLUENCE OF FEED RATE ON SURFACE ROUGHNESS OF TIC–WC CARBIDE AND AL2O3 CERAMICS SAWN-OFF WITH INNER EDGE OF DIAMOND DISC

2010 ◽  
Vol 2 (4) ◽  
pp. 88-90
Author(s):  
Raimundas Mikolaitis ◽  
Valdas Bukauskas ◽  
Vadim Mokšin ◽  
Vytautas Striška
Keyword(s):  
Surface Roughness ◽  
Grain Size ◽  
Tungsten Carbide ◽  
Feed Rate ◽  
Aluminium Oxide ◽  
Cutting Process ◽  
Feed Speed ◽  
Average Roughness ◽  
Cutting Machine ◽  
Diamond Disc

The paper presents results of measurements of surface roughness of titanium-tungsten carbide (T14K8) and aluminium oxide (Al2O3) ceramics surfaces sawn-off with inner edge of diamond disc. The cutting process was performed by cutting machine “АЛМАЗ-4” with 60/40 grain size disc. The dependence of average roughness Ra of the sawn-off surface on feed speed of the workpiece was established.

Diamond Disc Pad Conditioning in Chemical Mechanical Polishing: A Literature Review of Process Modeling

2009 ◽  
Author(s):  
Emmanuel A. Baisie ◽  
Z. C. Li ◽  
X. H. Zhang
Keyword(s):  
Process Modeling ◽  
Chemical Mechanical Polishing ◽  
Research Work ◽  
Mechanical Polishing ◽  
Process Models ◽  
Future Research ◽  
Process Conditions ◽  
Paper Briefly ◽  
Pad Conditioning ◽  
Diamond Disc

Chemical Mechanical Polishing (CMP) is a major manufacturing step extensively used to planarize semiconductor wafers. In CMP, the polishing pad surface is glazed by residues. A diamond disc conditioner is used to dress the pad to regenerate new pad profile and asperity in order to maintain favorable process conditions. This paper presents a review on process modeling of diamond disc pad conditioning in CMP. Following the introduction, the paper briefly introduces a technical background of the conditioning process and process control. It then summarizes research work on the various analytical process models proposed and ends with conclusions and topics for future research.

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