Selçuk TEVRÜZ, 030070128, 9th week

Chip Breakers (April 7, 2011 - 00:40)

Chip breakers are important element of tool design. Ductile materials such as low carbon steel, copper, aluminium, zinc, brass, etc. when, produce long continuous ships which are difficult to handle and dispose of as they occupy large volumes. The chip breaking and chip curl have assumed great importance.

Chip breakers are obstacles provided in the cutting tools which reduce the swarf into small pieces as they are formed. The metal plastically deformed during cutting resulting in work hardening. The chip breaker performs effectively with work hardened material. There are basically two types of chip breakers.

(i) Groove type

(ii) Obstruction type

(Singal R.K., Singal M., Singal R., Fundamentals of Machining and Machine Tools, 2008, pg.101)

Electrochemical Machining (ECM) (April 7, 2011 - 00:49)

Application of the electrochemical processes for machining has become one of the most prospective fields for manufacturing. These processes use the principle of metal removel by the electrochemical means and are an enhancement of the chemical machining process. In the electrochemical processes, an electrolytic cell is formed by using workpiece as anode and a cathode of suitable material having the shape of tool in the midst of an electrolyte solution. The well-known Faraday's laws of electrolysis govern the metal removal. The metal is removed in the form of sludge formed by the electrochemical and chemical reactions occuring in the electrolytic cell, which precipitates at the bottom. Hence, these processes are known as electrochemical machining processes.

(Parashar B.S.N., Mittal R.K., Elements of Manufacturing Processes, 2006, pg.335)

Electrochemical Grinding (ECG) (April 7, 2011 - 00:57)

The basic apparatus used in the aspect of ECG is shown in Fig. 4.18. The main feature is the use of a grinding wheel in which an insulating abrasive, such as diamond particles, is the set in a conducting bonding material. This wheel becomes the cathode-tool. The non-conducting particles act as a spacer between the wheel and workpiece, providing a constant inter-electro gap, through which electrolyte is flushed.

(McGeough J.A, Advanced Methods of Machining, 1988, pg.82)

Optical Encoder (April 7, 2011 - 07:50)

Very often, it is required to detect the position, velocity, acceleration and direction of movement of rotors, shafts, pistons, of the actuating devices such as rotary machines and translational systems. This is achieved by the use of optical encoders. The optical encoder is a device, which provides encoded pulsed signals in response to the movement. Continuous optical signals are modulated (coded) by the use of a specially designed rotating disk containing code patterns called 'track'. The pattern or track on the disk consists of alternate appearance of opaque and transparent segment and the pattern is circular. Basically, two types of encoders, such as incremental encoder and absolute encoder exist.

(Mahalik N.P., Mechatronics, 2nd reprint, 2006, pg.170)