Author: Haroon Khalil
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Process Parameters
The variation in material removal rate with different parameters is shown graphically in Figure 23.2. In Figure 23.2 (a), the material removal rate increases with increase in mass flow rate, and after the certain limit again material removal rate decreases with increase in material removal rate. In Figure 23.2 (b), with increase in the velocity of abrasive particles…
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Principle of Operation
In this process, material removal takes place due to tiny brittle fracture of metallic layer with high velocity impact of abrasive particles. Therefore, this method of machining is more suitable for brittle materials. A high velocity jet of dry air, CO2 or nitrogen gas containing abrasive particles strikes the workpiece at the point where cutting or…
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Important UCM Processes
Some important unconventional machining processes discussed in this text are listed as follows:
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Main Characteristics of UCM
The main characteristics of UCM can be summarized as follows:
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INTRODUCTION
Unconventional machining (UCM) process is completely non-mechanical. In this process, there is no chip formation. Melting and evaporation of unwanted metal or removal of the metal in the form of powder due to brittle fracture of the metallic layers performs machining operation. These processes are used for machining of difficult profile and for very hard…
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DIRECT NUMERICAL CONTROL (DNC)
Direct numerical control (DNC) can be defined as a manufacturing system in which a number of machines are controlled by computer through direct connection and in real time. The tape reader is omitted in DNC, thus relieving the system of its least reliable component. Instead of using the tape reader, the part program is transmitted…
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COMPARISON OF NC AND CNC MACHINES
NC machines offered a reliable way of producing machine parts using pre-programmed commands. These commands consisted of alphanumeric characters defined by the RS233 IEEE code. These characters were coded on punch paper tape in formats specifically planned for a certain machine tool. These programs (punched tape) would then be read into the NC control using…