Semi-permanent grinding wheels for internal grinding operations

Abstract

The thesis deals with the role of semi-permanent abrasives in internal grinding. The abrasives dealt with are diamond and cubic boron nitride. To determine this role the application of conventional abrasives are explored: together with the specification for finished parts. The performance of conventional abrasives determines the minimum objectives that must be attained for the acceptance of semi-permanent abrasives by industry. The type and form of semi-permanent wheels and their method of preparation for grinding are dealt with and found to be very important for the successful application of semi-permanent abrasives. The factors influencing selection of semi-permanent abrasives are explored in Chapter 3 together with details of performance, wear characteristics, and applications currently in use. Chapter 4 of the thesis details the equipment selected to carry out the test programme and the manner in which testing is carried out. Consideration is given to the economic viability of the abrasives by means of two techniques in Chapter 6. The first technique aims to establish the optimum metal removal rate by means of differentiation method. Results obtained in this manner are confirmed by direct plots of cost vs. metal removal rate. Comparison is made with conventional abrasive costs obtained by reference to standard time data for the same operation. Grinding tests using semi-permanent abrasives are used to assess the effects of the process variables, wheelspeed, traverse rate and infeed on the grinding performance of the wheels and the results obtained for surface finish, taper and bore profile.