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A new cutting tool is always well-defined and sharp at the onset of the metal cutting process and gradually losses these properties as the machining process advances. Similarly, at the beginning of the machining process, amplitude of tool vibrations is considerably low and it increases gradually and peaks at the end of the service period of the cutting tool while machining. It is significant to provide a corresponding real-time varying damping to control this chatter, which directly influences accuracy and quality of productivity. This paper aims to review the literature related to the application of smart fluid to control vibration in metal cutting and also focused on the challenges involved in the implementation of active control system during machining process.

Smart dampers, which are used as semi-active and active dampers in metal cutting, were reviewed and the research studies carried out in the field of the magnetorheological (MR) damper were concentrated. In smart materials, MR fluids possess some disadvantages because of their sedimentation of iron particles, leakage and slow response time. To overcome these drawbacks, new MR materials such as MR foam, MR elastomers, MR gels and MR plastomers have been recommended and suggested. This review intents to throw light into available literature which exclusively deals with controlling chatter in metal cutting with the help of MR damping methods.

Using an MR damper popularly known for its semi-active damping characteristics is very adaptable and flexible in controlling chatter by providing damping to real-time amplitudes of tool vibration. In the past, many researchers have attempted to implement MR damper in metal cutting to control vibration and were successful. Various methods with the help of MR fluid are illustrated.

A new cutting tool is always well-defined and sharp at the onset of metal cutting process and gradually losses these properties as the machining process advances. Similarly, at the beginning of the machining process, amplitude of tool vibrations is considerably low and it increases gradually and peaks at the end of service period of cutting tool while machining. Application of MR damper along with the working methodology in metal cutting is presented, challenges met are analyzed and a scope for development is reviewed.

This study provides corresponding real-time varying damping to control tool vibration which directly influences accuracy and quality of productivity. Using an MR damper popularly known for its semi-active damping characteristics is very adaptable and flexible in controlling chatter by providing damping to real-time amplitudes of tool vibration.

This study attempts to implement smart damper in metal cutting to control vibrations.

It is significant to provide corresponding real-time varying damping to control tool vibration which directly influences accuracy and quality of productivity.

FOR the purpose of this paper discussion is only centred around rubber mouldings for various purposes. Sealants, adhesives, tyres etc. are covered elsewhere in the symposium.

THE advent of the integral fuel tank over twenty years ago presented considerable sealing problems, due to both deficiencies in design and lack of suitable sealing compounds.

2. Elastomers A wide variety of elastomers, generally synthetic, are used in modern valves of the butterfly and diaphragm types with the dual function of lining/protecting internal metal surfaces in contact with the duty and providing the necessary interference for sealing. Without resorting to exotic and expensive metals of construction, even most aggressive services can be successfully handled by variation of elastomer type, while the particular compound is designed to still retain the physical characteristics necessary for optimum sealing. The number of permutations is thus large and indeed one manufacturer offers as many as 18 different resilient liner options. The main elastomer types are summarised:

Du Pont Changes. S.W. MCCUNE III has been promoted from Deputy Managing Director to Managing Director of the Du Pont Co. (United Kingdom) Ltd. He succeeds W. H. MCCOY, who returns to the U.S.A. on special assignment with the parent company in Wilmington, Delaware. A graduate in chemical engineering of Princetown University, Mr. McCune has had over 20 years' experience in elastomers research and sales work.

During December, Compounding Ingredients Ltd were one of sixteen companies who exhibited at the US Trade Center Exhibition of high performance materials.

Winn & Coales appoint new MD. Mr Alan Lewis, MInstM, has been appointed managing director of Winn & Coales (Denso) Ltd, succeeding Mr Eddy Webb on the latter's retirement after 13 years as the firm's Chief Executive.

ON December 20th, 1910, Mr. E. W. Dunne, the inventor of the arrow‐headed, tail‐less, twin screw biplane, made an experimental flight which deserves greater recognition than it has perhaps received. In order to demonstrate the inherent stability of the design, he flew a circuit at Eastchurch “hands‐off” while writing his observations of its behaviour. To do this he provided the controls with a set of locking levers designed to give a small number of set positions to correspond with turns, climbing, etc. The test was completely successful and Mr. Dunne returned safely to terra‐firma albeit this was the first time that he had turned this particular machine at any height !

hydrolysis can be described as the reaction between water and another material in which a definite chemical change occurs. Materials which do not react with water can be said to possess hydrolytic stability. Polyurethanes can be hydrolysed by water under certain conditions and the chemical changes involved result in a deterioration in properties of the material. These changes can be followed chemically or physically but under severe conditions the degradation is readily apparent. In these cases the polyurethane can change from being a tough elastic material to a soft plastic substance with little or no strength.

The ability to rise like a helicopter, tilt its rotors forward and fly like an airplane puts unusual demands on tiltrotor bearings, links and springs. Add to this stringent requirements for high reliability and low maintenance and you've got one tought assignment. Innovative and sophisticated natural rubber products from Lord Corporation have met the challenge.