5 Abrasive Processes (Grinding)
Version 2 ME, IIT Kharagpur
Lesson
28 Selection of wheels and their conditioning
Version 2 ME, IIT Kharagpur
Instructional Objectives
At the end of this lesson the students would be able to (i) (ii) (iii) (iv) (v) identify need and purpose of grinding wheel specification state the role of various compositional parameters of the grinding wheel state the logical steps in selecting a grinding wheel recognize need and purpose of grinding wheel conditioning illustrate various methods of wheel conditioning
28. Grinding wheels
Grinding wheel consists of hard abrasive grains called grits, which perform the cutting or material removal, held in the weak bonding matrix. A grinding wheel commonly identified by the type of the abrasive material used. The conventional wheels include aluminium oxide and silicon carbide wheels while diamond and cBN (cubic boron nitride) wheels fall in the category of superabrasive wheel.
28.1 Specification of grinding wheel
A grinding wheel requires two types of specification (a) Geometrical specification (b) Compositional specification
28.1.1 Geometrical specification This is decided by the type of grinding machine and the grinding operation to be performed in the workpiece. This specification mainly includes wheel diameter, width and depth of rim and the bore diameter. The wheel diameter, for example can be as high as 400mm in high efficiency grinding or as small as less than 1mm in internal grinding. Similarly, width of the wheel may be less than an mm in dicing and slicing applications. Standard wheel configurations for conventional and superabrasive grinding wheels are shown in Fig.28.1 and 28.2.
Fig.28.1: Standard wheel configuration for conventional grinding wheels
Version 2 ME, IIT Kharagpur
Fig.28.2: Standard wheel configuration for superabrasive wheel 28.1.2 Compositional specifications Specification of a grinding wheel ordinarily means compositional specification.