Question

give four examples of surface finish processes as used in machining. give also a short explanation of each.

Answer 1

 

 

Grinding is a material removal process accomplished by abrasive particles that are contained in a bonded grinding wheel rotating at very high surface speeds. The grinding wheel is usually disk-shaped and is precisely balanced for high rotational speed

Honing is an abrasive process performed by a set of bonded abrasive sticks. A common application is to finish the bores of internal combustion engines. Other applications include bearings, hydraulic cylinders, and gun barrels. Surface finishes of around 0.12 um

lapping uses a fluid suspension of very small abrasive particles between the workpiece and the lapping tool. The process is illustrated in Figure 25.17 as applied in lens-making. The fluid with abrasives is referred to as the lapping compound and has the general appearance of a chalky paste. The fluids used to make the compound include oils and kerosene. Common abrasives are aluminum oxide and silicon carbide

Polishing is used to remove scratches and burrs and to smoothen rough surfaces by means of abrasive grains attached to a polishing wheel rotating at high speed—around 2300 m/min (7500ft/min). The wheels are made of canvas, leather, felt, and even paper; thus, the wheels are somewhat flexible

Buffing is similar to polishing in appearance, but its function is different. Buffing is used to provide attractive surfaces with high luster. Buffing wheels are made of materials similar to those used for polishing wheels—leather, felt, cotton, etc.—but buffing wheels are generally softer. The abrasives are very fine and are contained in a buffing compound that is pressed into the outside surface of the wheel while it rotates

GRINDING

 LAPPING

SUPERFINISHING

POLISHING AND BUFFING