Machining

Machining is any of various processes in which a piece of raw material is cut into a desired final shape and size by a controlled material-removal process; it means the removal of material from a workpiece. Machining is a part of the manufacture of many metal products, but it can also be used on materials such as wood, plastic, ceramic, and composites. It covers several processes, which we usually divide into the following categories:

Cutting: generally involving single-point or multipoint cutting tools, each with a clearly defined geometry.

Abrasive processes, such as grinding.

Non-traditional machining processes utilizing electrical, chemical, and optimal sources of energy. The traditional machining includes primers on turning, milling, drilling, and grinding. It also includes computer applications which are being supported by the primers. The non -traditional machining includes primers on the topics such as ECM, EDM, LBM, and USM. Some of the processes are summarized as following:

Turning is used to remove material from a rotating workpiece to generate a cylindrical shape. The primary motion is provided by rotating the workpiece, and the feed motion is achieved by moving the cutting tool slowly in a direction parallel to the axis of rotation of the workpiece.

Milling is a rotating tool with multiple cutting edges is moved slowly relative to the material to generate a plane or straight surface. The direction of the feed motion is perpendicular to the tool's axis of rotation. The speed motion is provided by the rotating milling cutter.

Drilling is used to create a round hole. It is accomplished by a rotating tool that typically has two or four helical cutting edges. The tool is fed in a direction parallel to its axis of rotation into the workpiece to form the round hole.Electrochemical machining (ECM) is a method of removing metal by an electrochemical process. It is normally used for mass production and is used for working extremely hard materials or materials that are difficult to machine using conventional methods. Its use is limited to electrically conductive materials.

Electrical discharge machining (EDM), spark machining, spark eroding, burning, die sinking, wire burning or wire erosion, is a manufacturing process whereby a desired shape is obtained using electrical discharges (sparks.

Laser beam machining (LBM) is a non-traditional subtractive manufacturing process, a form of machining, in which a laser is directed towards the work piece for machining. This process uses thermal energy to remove material from metallic or nonmetallic surfaces. Laser represents the full form of Light Amplification by Stimulated Emission of Radiation.

Ultrasonic machining (USM) is a subtraction manufacturing process that removes material from the surface of a part through high frequency, low amplitude vibrations of a tool against the material surface in the presence of fine abrasive particles.