A Markovian Finishing Process

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
M. A. S. Mohamed
Keyword(s):  
Triangular Form ◽  
Workpiece Surface ◽  
Finishing Process ◽  
Tool Surface ◽  
Markov Matrix ◽  
Abrasive Surface ◽  
Matrix Mapping ◽  
Abrasive Tools ◽  
Finishing Processes ◽  
Abrasive Paper

Addressed is the mechanism of finishing processes for a workpiece surface using hard abrasive tools such as grinding, abrasive paper, and filing. The mechanism is intended to monitor the gradual changes of the workpiece surface state roughness as the tool is applied for several strokes. Based on a number of common features, the present study simulates each rubbing stroke as a Markov process, and each set of several strokes as a Markov chain. In the simulating model, the discrete probabilistic properties of a specific tool abrasive surface can be expressed in terms of a corresponding Markov matrix operator. Thus, the tool action after one rubbing stroke is obtained via a matrix mapping from a given state roughness to a subsequent state roughness of the workpiece surface. Although the suggested model is capable to handle a comprehensive finishing mechanism, the study focuses on the simple case of zero feeding using a hard abrasive tool, in which the Markov matrix shrinks to a special triangular form. Main findings show that major aspects of the tool surface are transferred to the stepwise roughness state of the workpiece immediately after the first stroke. In addition, regardless of the initial roughness state of the workpiece surface, whether with flat or randomly distributed heights, the ultimate state roughness is unique and definitely features the theoretical case of a plain flat surface. However, this theoretical case is infeasible since it can only be reached after infinite number of strokes.

scholarly journals Edge finishing of large turbine casings using defined multi-edge and abrasive tools in automated cells

2021 ◽  
Author(s):  
Adrian Rodríguez ◽  
Mikel González ◽  
Octavio Pereira ◽  
L. Norberto López de Lacalle ◽  
Mikel Esparta
Keyword(s):  
Operating Time ◽  
Added Value ◽  
Global Challenge ◽  
Industrial Sectors ◽  
Finishing Process ◽  
Aero Engine ◽  
Edge Location ◽  
Abrasive Tools ◽  
Edge Finishing ◽  
Finishing Processes

AbstractAutomate finishing processes is a global challenge in several industrial sectors. Concretely, when dealing with aero-engine components, only simple finishing processes are automated nowadays. Most of the high-added value components manufactured are finished hand working, using deburring and polishing manual techniques. The driver of the proposed work is to achieve the necessary knowledge to introduce in a production line a complete finishing process for automated robotic deburring applications with low machinability materials (Inconel 718 in this case-study) on aero-engine casings with complex geometries: extruded casting bosses, internal features, etc. For this purpose, a three-step methodology is presented and analysed, providing a feasible workflow combining visual inspection for part positioning and edge location, with multi-edge solid tools and flexible abrasive tools to automate finishing operations, taking into account all process singularities. Results show that, using correct techniques, processes and parameters, an automated finishing process reducing operating time can be implemented in production lines.

scholarly journals Edge Finishing of Large Turbine Casings Using Defined Multiedge And Abrasive Tools In Automated Cells

2021 ◽  
Author(s):  
Adrian Rodríguez ◽  
Mikel González ◽  
Octavio Pereira ◽  
Luis Norberto López de Lacalle ◽  
Mikel Esparta
Keyword(s):  
Operating Time ◽  
Added Value ◽  
Global Challenge ◽  
Industrial Sectors ◽  
Finishing Process ◽  
Aero Engine ◽  
Abrasive Tools ◽  
Edge Finishing ◽  
Finishing Processes ◽  
Engine Components

Abstract Automate finishing processes is a global challenge in several industrial sectors. Concretely, when dealing with aero-engine components, only simple finishing processes were automated nowadays. Most of the high-added value components manufactured are finished hand working, using deburring and polishing manual techniques. The driver of the proposed work is to achieve the necessary knowledge to introduce in a production line a complete and finishing process for automated robotic deburring applications with low machinability materials (Inconel 718 in the case of study) on aero-engine casings with complex geometries: extruded casting bosses, internal features, etc. For this purpose, a three-step methodology is presented and analysed, providing a feasible workflow combining multi-edge solid tools and flexible abrasive tools to automate finishing operations taking account all the process drawbacks and peculiarities. Results show that using the correct techniques, processes and parameters, an automated finishing process that reduces operating time can be implemented in production lines.

Development of a Technique for the Study of the Coated Abrasive Surface Wear

2021 ◽  
Vol 313 ◽  
pp. 66-71
Author(s):  
V.S. Lyukshin ◽  
Dmitry B. Shatko ◽  
P.A. Strelnikov
Keyword(s):  
Measurement Accuracy ◽  
Surface Wear ◽  
Abrasive Tool ◽  
Effective Technique ◽  
Grain Sizes ◽  
Tool Surface ◽  
Abrasive Surface ◽  
Specialized Equipment ◽  
Abrasive Tools ◽  
Coated Abrasives

Wear of abrasive tools, including coated abrasives, is an important performance feature. A large number of theoretical works and practical studies are devoted to wear assessment issues. In practice, there are many direct and indirect approaches to measuring wear of an abrasive tool. At the same time, many of them have significant shortcomings such as assessment complexity, high time costs, a significant share of manual labor, low measurement accuracy, the need to use specialized equipment, etc. Based on the foregoing, the development of an effective technique for assessing the coated abrasive wear with the use of information and analytical technologies is very relevant and promising. This work is devoted to the development of an original technique for determining the wear of coated abrasives and studying of the tool surface texture. Some results of studies on the wear of coated abrasives of various grain sizes and manufacturers are presented in the article.

A Comprehensive Review on Magnetic Abrasive Finishing Process

2016 ◽  
Vol 18 ◽  
pp. 1-20 ◽  
Author(s):  
Mohannad Naeem Houshi
Keyword(s):  
Surface Finish ◽  
Low Cost ◽  
High Surface ◽  
Functional Requirements ◽  
Workpiece Surface ◽  
Magnetic Abrasive Finishing ◽  
Finishing Process ◽  
Abrasive Finishing ◽  
Superior Surface ◽  
Finishing Processes

In the nanotechnology era, the need for products with high quality and surfaces with free-from damage has become an urgent necessity. Many components in the precision industries such as electronics, automobile, medical, and aviation require high surface finish to meet their functional requirements, such as, reducing fluid flow resistance, friction, optical losses and increase fatigue strength. However, the scale of such surface quality cannot be achieved by traditional finishing methods. To overcome these limitations, many advanced finishing processes have been developed such as abrasive flow finishing, magnetorheological fluid finishing, magnetic float polishing, and chemical mechanical polishing and magnetic abrasive finishing. Magnetic abrasive finishing (MAF) is one of advanced finishing processes which offers superior surface finish over conventional finishing processes, because of its self-adaptability to finish of different geometric shapes, its a gentle tool which does not impact workpiece surface, its capability to polish advanced engineering materials and its low cost. This article has been focused on MAF, as well as reviewing of advanced finishing processes. The recent researches and challenges of MAF have been discussed as well.

Five-Axis Constrained and Optimal Orientation Planning

1993 ◽  
Author(s):  
Khorssand Haghpassand
Keyword(s):  
Optimization Problem ◽  
Machining Process ◽  
Surface Finishing ◽  
Tool Geometry ◽  
Drilling Process ◽  
Workpiece Surface ◽  
Optimal Orientation ◽  
Manufacturing Applications ◽  
Finishing Processes ◽  
Five Axis

Abstract The five-axis constrained and optimal orientation planning is formulated as a design optimization problem that incorporates the process machine’s kinematic constraints with the workpiece and tool geometry, to obtain a constrained setup orientation which exploits the maximum capabilities of existing machines. This work will introduce this problem, and will obtain the setup orientation for two different types of rotation structures, i.e., tool rotation and table rotation in O(N) time. Further, the obtained constrained setup orientation, will be augmented to incorporate the workpiece surface magnitude, along with different machine rotation structures, to obtain an optimal setup orientation for different machine rotation structures. The drilling process is also introduced and formulated as additional constraints to the optimization problem. The primary application of the introduced algorithms, is the machining process, where, they can efficiently reduce the number of tool motions and surface finishing processes. However, the solution is very suitable for many manufacturing applications, such as inspection, assembly, robotics, painting, welding, aerospace, electronic surface mount technology, and etc.

Tool Surface Topographies for Controlling Friction and Wear in Metal-Forming Processes

1998 ◽  
Vol 120 (3) ◽  
pp. 517-527 ◽  
Author(s):  
Simon Sheu ◽  
Louis G. Hector ◽  
Owen Richmond
Keyword(s):  
Surface Topography ◽  
Metal Forming ◽  
Friction And Wear ◽  
Workpiece Surface ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Single Scale ◽  
Surface Topographies ◽  
Tool Surface ◽  
Scale Surface

A conceptual framework is introduced for the design of tool surface topographies in bulk metal forming processes. The objective of the design is to control friction to desired levels while minimizing wear of the workpiece and tool surfaces and adhesive metal transfer between the workpiece and tool. Central to the design framework are the tool/workpiece interface properties of lubricant retention and interface permeability. Lubricant retention refers to the capacity of an interface to retain lubricant rather than freely channel it to the exterior of the tool/workpiece conjunction. Permeability refers to the capacity to distribute lubricant to all areas within the conjunction. These properties lead to the concept of two-scale surface topography consisting of a fine scale background of interconnected channels on which is superimposed an array of coarser-scale cavities. Control of friction and wear is achieved by designing the tool surface topographies at these two scales to address the unique tribological conditions of specific bulk metal forming processes. The coarser scale is designed to ensure adequate supply of lubricant within the conjunction. The finer scale is designed to ensure adequate delivery of lubricant to all parts of the conjunction where nascent workpiece surface is being formed. The design concepts are illustrated with results from laboratory experiments using the rolling process as an example, and comparing the performance of various roll surface topographies under similar processing conditions. A two-scale surface topography consisting of hemispherical cavities distributed across a background surface of finer scale, interconnected channels was shown to reduce friction compared to a single-scale ground finish, but not as much as a single-scale coarse topography consisting of densely-packed cavities produced by an electrical discharge treatment. On the other hand, the smoother cross-sections of the cavities, especially when elongated in the direction of greatest relative motion, produced significantly less wear than either of the single-scale tool surface treatments. It is concluded that two-scale engineering of tool surface topographies based upon the concepts of lubricant retention and interface permeability can provide a broad basis for achieving desired levels of interface friction while minimizing workpiece surface wear and adhesive material transfer in many metal-forming processes.

Development of polymer abrasive medium for nanofinishing of microholes on surgical stainless steel using abrasive flow finishing process

2019 ◽  
Vol 234 (3) ◽  
pp. 355-370 ◽  
Author(s):  
Sachin Singh ◽  
M Ravi Sankar
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
High Surface ◽  
Machining Process ◽  
Abrasive Medium ◽  
Finishing Process ◽  
Drug Eluting ◽  
Finishing Processes ◽  
Abrasive Flow Finishing

The finishing operation completes the manufacturing cycle of a component. Depending on the level of finish (micro and nano) required on the component surface, different finishing processes are employed. Several components employed in medical, automotive and chemical industries use different types of passages for the flow of fluid. The surface roughness of such passages decides the functionality of the component. Drug-eluting stents are one of the recent advancements in the medical industry. They possess microholes for release of the drugs to the point of cure. Microholes are mostly fabricated by thermal-based micromachining processes that generate metallurgically destroyed surface layers with high surface roughness. Later, these are polished using chemical or electrochemical polishing techniques, which chemically destroy the quality of the surface. These metallurgically and chemically modified (destroyed/changed) rough surfaces on the microhole wall can cause contamination of the drug. So in this article, microholes of diameter 850 ± 30 µm are fabricated in surgical stainless steel (SS 316L) workpieces using the electric discharge micromachining process. Machined microholes are finished by employing a non-traditional finishing process called the abrasive flow finishing process. Instead of using a commercially available expensive abrasive flow finishing medium, the economic medium is fabricated in-house, and its rheological study is carried out. Machining process produces microholes with a surface roughness of about 1.40 ± 0.10 µm. Later, by finishing of microholes with the abrasive flow finishing process, the surface roughness is reduced to 150 nm (percentage surface roughness improvement of about 88.53%). Therefore, the abrasive flow finishing process is a viable alternative to chemical-based polishing processes as it removes the recast layer and achieves nanosurface roughness.

Novel Contact Sensor for High-Speed Machining

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Valéry Bourny ◽  
Florent Swingedouw ◽  
Thierry Capitaine ◽  
Aurélien Lorthois ◽  
Jérôme Dubois ◽  
...  
Keyword(s):  
Embedded System ◽  
High Speed ◽  
Ease Of Use ◽  
High Speed Machining ◽  
Workpiece Surface ◽  
Finishing Process ◽  
Contact Sensor ◽  
Magnitude Variation ◽  
Machining Operations ◽  
First Contact

This work presents a method implemented in an embedded system to detect the first contact between a high-speed machine tool and a workpiece surface with high accuracy, reliability and ease-of-use. This method is based on impedance magnitude variation measurements and the computation of a correlation function. A specific sensor was designed from this method for testing purposes in actual industrial conditions. This work is focused on the detection of the first contact between the tool and the workpiece surface. The purpose of this paper is to explore the efficiency of impedance spectroscopy and to identify a method to detect the first contact between a tool and a workpiece efficiently in high-speed machining operations and for the finishing process in particular.

Development and Rheological Characterisation of Abrasive Flow Finishing Medium for Finishing Macro to Micro Features

2020 ◽  
Vol 70 (2) ◽  
pp. 190-196
Author(s):  
Sachin Singh ◽  
M. Ravi Sankar
Keyword(s):  
Surface Roughness ◽  
Surface Finish ◽  
Recast Layer ◽  
Technological Advancement ◽  
Minimal Cost ◽  
Finishing Process ◽  
Fine Surface ◽  
Micro Features ◽  
Finishing Processes ◽  
Abrasive Flow Finishing

Technological advancement demands the manufacturing of components with a fine surface finish at a minimal cost. This scenario acts as the driving force for the research communities to develop economic finishing processes. Abrasive flow finishing (AFF) is one of the advanced finishing processes employed for finishing, deburring, radiusing and recast layer removal from the workpiece surfaces. AFF process uses a finishing medium that acts as a deformable tool during the finishing process. It is the rheological properties of the medium that profoundly influences the end surface finish obtained on the workpiece after the AFF process. In the current work, an attempt is made to develop an economic AFF medium by using viscoelastic polymers i.e., soft styrene and soft silicone polymer. Detailed static and dynamic characterisation of the medium is carried out. Later, to study the finishing performance of the developed medium, AFF experiments are performed for the finishing of macro and micro feature components. The experimental study showed that the nano surface finish could be achieved by varying the viscosity of the developed medium. Developed medium achieved 89.06 per cent improvement in surface roughness during finishing of tubes (macro feature component), while 92.13 per cent and 88.11 per cent surface roughness improvement is achieved during finishing of microslots and microholes (micro feature component), respectively.

scholarly journals Optimization and Rejection Analysis of IC Engine Rocker Arm

2021 ◽  
Vol 9 (8) ◽  
pp. 2036-2044
Author(s):  
Chetan Jadhav
Keyword(s):  
Surface Roughness ◽  
Great Influence ◽  
High Wear Resistance ◽  
Process Stability ◽  
Ic Engine ◽  
Cycle Times ◽  
Roughness Analysis ◽  
Abrasive Tools ◽  
Finishing Processes ◽  
Technical Products

Abstract: Today, many technical products need high-precision cylindrical bores which are used, e.g. as a fit or as guidance elements for pistons and shafts. They often need geometric and form accuracy with tolerances less than 1 μm, surface qualities with a roughness less than 1 μm and a high wear resistance. To reach higher production accuracy and better process stability in shorter cycle times, new approaches for the regulation of an automated honing process have to be developed. Due to the great demands regarding the surface roughness which has a great influence on the service life and reliability of parts and the researches of the technical and economical performances of finishing processes were made to optimize the process parameters and constructive parameters of the abrasive tools Keywords: Surface roughness, Analysis, Honing, process parameter, Rocker arm

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