Free Educational Notes
Introduction to Ultrasonic Machining: Ultrasonic machining is a subtractive manufacturing process that removes material from the surface of a part through low-amplitude, high-frequency vibrations of a tool against the material surface in the presence of fine abrasive particles. Ultrasonic vibration machining physically operates through the mechanism of microchip or erosion on the surface of the…
Although iron and steel are the most common and important materials that we have to deal with, there are other metals used in the workshop that you will need to have some knowledge of. The main pure metals from the non-ferrous group that the reader will have to deal with are aluminium, copper, lead, tin…
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All of the workshop engineer’s energy is directed towards some aspect of changing the shape of the metal, and we will now discuss the general issue of hot and cold working. Cold working means subjecting the metal to forces that cause it to undergo plastic deformation when it is below the lowest critical temperature (perlite…
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The purposes of annealing are (1) To soften steel so it can be machined more easily (2) To relieve internal stresses that may have been caused by metalworking or uneven shrinkage in the casting. The process involves (A) Heat slowly to the required temperature (B) Holding at this temperature long enough to allow internal changes…
In the past, a great deal of heat treatment, mainly of tools, was done in a blacksmith’s fire, and even today this method is still used in some places. At best, however, this heating method is unreliable, as for all but small tools the heating is not uniform and, more importantly, estimating the correct temperature…
What are different Mechanical properties of metals? Following are the Mechanical Properties of Metals Brittleness It is the property of breaking without not too much permanent distortion. It may be due to the fragility of the grain boundaries or the crystals themselves. Cast iron is brittle because its structure is broken up by chips of…
Precise relative movement of the tool relative to the workpiece is necessary to carry out the desired machining process. Motion control systems in Numerical Control (NC) machining systems can be categorized into three basic types: point-to-point, straight cut, and contour. 1. NC point to point This type of motion control system is also known as…
The following steps must be performed for the successful operation of the NC machine tool. 1. Process Planning The design of the work to be manufactured must be interpreted in terms of the manufacturing processes that must be performed on the work. The process of interpreting the engineering drawing in the manufacturing process is known…
A more advanced version of the NC system is direct numerical control (DNC) machines where one computer controls multiple machines in real-time. The DNC system is not equipped with the tape reader and therefore increases the reliability of the machining system. The prepared part program is transmitted from the computer’s memory directly to the machine…
When basic and even on some machines all features are controlled using the instruction program is stored on a computer, then the numerical control system is known as computer numerical control systems. The growing trend of the downsizing of machine equipment led to the sale of CNC systems equipped with microcomputer-based controller units. CNC systems…
There are several material removal techniques that are performed using different machine tools. There are wide ranges of cutting tool materials that are used by machine tools. The different material removal techniques involved are: • Material removal with single point metal cutting tool. • Use of multipoint metal cutting tool for material removal. • Abrasives…
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