MILLING

                                        MILLING PROCESS

Milling is a machining operation in which a work piece is fed past a rotating cylindrical tool with multiple cutting edges. The axis of rotation of the tool is perpendicular to the feed direction. The tool is called the milling cutter and the cutting edges are called teeth. Mostly plane surfaces are created through milling. It’s an interrupted cutting operation; the teeth of milling cutter enter and exit work piece during each revolution. So, the tool material and cutter geometry must be chosen carefully to withstand cycles of impact forces and thermal shock.

Milling is used in the metal work industry and defined as the process of cutting, shaping and finishing a piece of metal. It is one of several metal working processes that include turning, welding, and fringing. Milling is used when more complex metal shape are desired. The process is used to create a number of metal parts and structures and everything from rings and bracelets bridges and freight ships . Typically, milling involves cutting away pieces of metal to create dovetails, threads, bevels, slots, and ridges. The grooved edges of coins are a simple example of the milling process.

Milling is the machining operation in which material is removed from the surface by using the multipoint rotating cutting tool known as milling cutter. milling cutter is known as multipoint cutting tool because it has equally spaced cutting teeth. This machine is most widely used due to fast production, high accuracy and good surface finish.

Milling process is one of the most fundamental and commonly encountered material removal operations in manufacturing process. The surface roughness is one of the important properties for evaluating the work piece quality during the end milling process. The surface roughness plays a great part in fatigue strength and corrosion resistance, surface friction, light reflection, ability of holding a lubricant, electrical and thermal contact resistance, appearance, cost, etc .High quality of the surface after end milling makes further machining of the surface not necessary, which brings about decreased power consumption and environment load. However, optimization of surface roughness is consistently challenged by its uncertainty of prediction model as well as various influencing parameters, which can be divided into controlled and non-controlled parameters. Main parameters of the first type includes spindle speed, feed rate, and depth of cut. And vibrations, tool wear, machine motion errors, and material non-homogeneity of both the tool and work piece, chip formation belong to the non-controlled parameters. The non-controlled cutting parameters are hard to reach and their interactions cannot be exactly determined.

It the process of cutting away material by feeding a work piece past a rotating multiple tooth cutter. The cutting action of many teeth around milling cutter provide a fast method of machining. The machined surface may be flat, angular, or curved. The may also be milled to any combination of shapes. The machine for holding the work piece, rotating the cutter, and feeding it is known as milling machine.

Milling is one of the basic machining processes.  Milling is a very versatile process capable of producing simple two dimensional flat shapes to complex three dimensional interlaced surface configurations.