Grinding of Steel-Ceramic-Composites

Steel-ceramic-composites offer a high potential as protective layers of mechanically and abrasively high loaded machine parts. The machining of steel-ceramic-composites is a high challenge for the process design due to the very different material properties of the brittle ceramic particles, embedded in the ductile steel matrix. Both materials have to be machined in ductile mode simultaneously to gain high surface qualities. Thus, the material separation mechanisms have to be understood for an adequate process design. In this paper, a new process characteristic is introduced that describes the influence of the grinding process settings on the process forces and workpiece surface roughness in grinding steel-ceramic-composites.

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Process design of a novel combination of peel grinding and deep rolling

Production Engineering ◽

10.1007/s11740-021-01092-w ◽

2021 ◽

Author(s):

Berend Denkena ◽

Alexander Kroedel ◽

Tobias Gartzke

Keyword(s):

Surface Properties ◽

Process Design ◽

High Surface ◽

Grinding Wheel ◽

Deep Rolling ◽

Workpiece Surface ◽

High Surface Quality ◽

Cycle Times ◽

Increase In Productivity ◽

Process Combination

AbstractGrinding is mostly considered as a finishing operation by which a high surface quality is achieved. An increase in productivity is therefore limited by maintained surface properties such as the roughness or tensile residual stresses. Thus, a roughing operation is inevitable followed by a finishing operation, while both operations are separated, leading to larger cycle times and process costs. In this paper, a novel process combination is investigated in which the roughing is done by grinding and the finishing operation by deep rolling within one tool setup. In this way, both processes are conducted parallel within the primary processing time. The objective of this study is the knowledge of the characteristics of this process combination with regard to the workpiece surface integrity. Therefore, shafts are ground in peel grinding with varying grinding wheel types and process parameters and subsequently machined with deep rolling. The process combination is evaluated with regard to the process forces and the resulting surface properties. In addition, experiments using the process combination were conducted in order to investigate the transferability of the results towards the process combination. By this approach, it was found that the surface roughness was reduced up to 80% by deep rolling showing the potential of the process combination.

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Pilot Scale Testing of a New Radium-226 Removal Process

Water Quality Research Journal ◽

10.2166/wqrj.1985.018 ◽

1985 ◽

Vol 20 (2) ◽

pp. 55-67

Author(s):

W.B. Anderson ◽

P.M. Huck ◽

T.M.R. Meadley ◽

T.P. Hynes

Keyword(s):

Treatment Process ◽

No Reduction ◽

High Surface ◽

High Surface Area ◽

Barium Chloride ◽

Pilot Scale ◽

Activity Levels ◽

New Process ◽

Removal Efficiencies ◽

New Treatment

Abstract This paper describes the on-going pilot scale development of a new treatment process designed to remove radium-226 from uranium milling effluents. Presently, decants from Canadian uranium mining and milling tailings areas are treated with barium chloride to remove radium-226 prior to discharge into the environment. This is usually accomplished in large natural or man-made ponds which provide an opportunity for a (Ba,Ra)SO4 precipitate to form and subsequently settle. Sand filtration is sometimes used as a polishing step. This new process differs from conventional and other experimental processes in that it involves the use of a fluidized bed to facilitate the deposition of a (Ba,Ra)SO4 precipitate on a granular medium of high surface area. As a stand-alone treatment process, the new process is consistently able to reduce incoming radium-226 activity levels by 90-99%. Effluent levels of 10 pCi/L (0.370 Bq/L) or less have been achieved, depending on the influent activity levels. Recent testing of the process as a polishing step has demonstrated radium removal efficiencies up to 60% when the process influent was already less than 5 pCi/L (0.185 Bq/L). The process has been operated at temperatures ranging from 26°C down to 0.3°C with no reduction in efficiency. In contrast to treatment times in the order of days for conventional settling pond systems and hours for mechanical stirred tank/filtration systems, the new process is able to achieve these radium removal efficiencies in times on the order of one minute.

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Experimental investigation of the machining characteristics in diamond wire sawing of unidirectional CFRP

The International Journal of Advanced Manufacturing Technology ◽

10.1007/s00170-021-07146-8 ◽

2021 ◽

Author(s):

Lukas Seeholzer ◽

Stefan Süssmaier ◽

Fabian Kneubühler ◽

Konrad Wegener

Keyword(s):

Surface Quality ◽

Influencing Factors ◽

Material Properties ◽

High Surface ◽

Workpiece Surface ◽

High Surface Quality ◽

High Productivity ◽

Surface Temperatures ◽

Process Forces ◽

The Wire

AbstractEspecially for slicing hard and brittle materials, wire sawing with electroplated diamond wires is widely used since it combines a high surface quality with a minimum kerf loss. Furthermore, it allows a high productivity by machining multiple workpieces simultaneously. During the machining operation, the wire/workpiece interaction and thus the material removal conditions with the resulting workpiece quality are determined by the material properties and the process and tool parameters. However, applied to machining of carbon fibre reinforced polymers (CFRP), the process complexity potentially increases due to the anisotropic material properties, the elastic spring back potential of the material, and the distinct mechanical wear due to the highly abrasive carbon fibres. Therefore, this experimental study analyses different combinations of influencing factors with respect to process forces, workpiece surface temperatures at the wire entrance, and the surface quality in wire sawing unidirectional CFRP material. As main influencing factors, the cutting and feed speeds, the density of diamond grains on the wire, the workpiece thickness, and the fibre orientation of the CFRP material are analysed and discussed. For the tested parameter settings, it is found that while the influence of the grain density is negligible, workpiece thickness, cutting and feed speeds affect the process substantially. In addition, higher process forces and workpiece surface temperatures do not necessarily deteriorate the surface quality.

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Experimental Temperature Studies on Two Dimensional Ultrasonic Vibration Grinding the Nano-ZrO2 Ceramics

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.416.540 ◽

2009 ◽

Vol 416 ◽

pp. 540-545

Author(s):

Ping Yan Bian ◽

Bo Zhao ◽

Yu Li

Keyword(s):

Surface Temperature ◽

Ultrasonic Vibration ◽

High Surface ◽

Grinding Wheel ◽

Grinding Temperature ◽

Two Dimensional ◽

Workpiece Surface ◽

Grinding Parameters ◽

Thermocouple Method ◽

The Relationship

In processing of engineering ceramics materials with diamond grinding wheel, grinding heat is one of vital factors influencing workpiece surface quality. Grinding parameters have important influences on workpiece surface temperature distributions. Contrast experiments on grinding temperature of nanoZrO2 under common and two dimensional ultrasonic vibration grinding(TDUVG) were carried out in this paper by manual thermocouple method. The relationship between grinding parameters and grinding temperature was clarified through theoretical analysis and experiment confirmation. The research results show that with the increases of grinding depth, grinding speed, and decrease of working table speed, the workpiece’s surface temperature would heighten accordingly. Furthermore, comparing with high surface layer temperature in common grinding, which often results in grinding burn, TDUVG can reduce grinding temperature effectively.

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Ceramic Composites for Gas Turbine Engines via a New Process

Volume 2: Aircraft Engine; Marine; Microturbines and Small Turbomachinery ◽

10.1115/89-gt-316 ◽

1989 ◽

Cited By ~ 2

Author(s):

G. H. Schiroky ◽

A. W. Urquhart ◽

B. W. Sorenson

Keyword(s):

Gas Turbine ◽

Joint Venture ◽

New Technology ◽

Ceramic Composites ◽

Gas Turbine Engine ◽

Molten Metals ◽

Oxidation Reactions ◽

Turbine Engine ◽

New Process ◽

Engine Components

A new process for ceramic composites involves the growth of ceramic matrices through shaped preforms using directed oxidation reactions of molten metals. The preforms may consist of reinforcing fibers, whiskers, platelets, or particles, as needed to produce the desired properties in the finished component. This new technology is being developed by Lanxide Corporation and is being applied to gas turbine engine components by Du Pont Lanxide Composites Inc., a joint venture. The paper includes a description of the technology and a discussion of the status of its application to materials for gas turbine engine components.

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New Process Design for Biological Nutrient Removal

Water Science & Technology ◽

10.2166/wst.1992.0532 ◽

1992 ◽

Vol 25 (4-5) ◽

pp. 445-448 ◽

Cited By ~ 38

Author(s):

J. Wanner ◽

J. S. Čech ◽

M. Kos

Keyword(s):

Activated Sludge ◽

Process Design ◽

Laboratory Experiments ◽

Biological Process ◽

Biological Nutrient Removal ◽

Organic Substances ◽

Anaerobic Reactor ◽

New Process ◽

Denitrification Reactor ◽

P Removal

A new arrangement of the biological process for efficient COD, N and P removal has been proposed. The process consists of the anaerobic reactor where organic substances from waste water are sequestered into activated sludge, the nitrification reactor where ammonia-rich supernatant is oxidized, and the denitrification reactor where oxidized supernatant is mixed with the activated sludge separated from the anaerobic reactor. Laboratory experiments confirmed favorable characteristics of the proposed system.

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Microwave-Assisted Techniques (MATs); a Quick Way to Extract a Fragrance: A Review

Natural Product Communications ◽

10.1177/1934578x1300801040 ◽

2013 ◽

Vol 8 (10) ◽

pp. 1934578X1300801 ◽

Cited By ~ 3

Author(s):

Antonios K. Kokolakis ◽

Spyridon K. Golfinopoulos

Keyword(s):

Essential Oil ◽

Essential Oils ◽

Process Design ◽

Chromatographic Analysis ◽

Plant Material ◽

Antioxidant Properties ◽

Product Yield ◽

Heating Source ◽

Microwave Assisted ◽

New Process

In recent years Microwave-Assisted Techniques (MATs) have been introduced as a new process design and operation for essential oils extraction, representing a viable alternative to conventional old-type methods of distillation which are routinely used for the isolation of essential oils from herbs, flowers and spices prior to gas chromatographic analysis. The novelty of the technique lies in a microwave heating source generating a mixture of boiling solvent with the raw plant material settled above (or drenched inside). Several variations of distillation techniques are evaluated in terms of substantial energy saving, rapidity, product yield, cleanliness and product quality. Results confirm the effectiveness of MATs, which allow extraction of essential oils in shorter extraction time (up-to 9 times faster), using “greener” procedures and provide a higher quality essential oil with better sensory and antioxidant properties.

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