Exploitable results ELIMINATION OF THERMAL DAMAGE IN FORM GRINDING Thermal damage is a critical limiting factor in production of ground forms. This feature was investigated in this project in the context of form grinding associated with i) shoulder form, V and inverted V form grinding of precision alloy steel components made of case hardening steel (EN39B) and ball bearing steel (EN31) for the automotive fuel injection systems and ii) flute form grinding of HSS M2 twist drills. Models and general procedures for the design of high production economic form grinding cycles for the indicated material types with assured product quality have been successfully developed. These are based on force and temperature models developed in this project for form grinding and the new insight about the relation between grinding temperature and material specific thermal damage during grinding using conventional (Al2O3) and super abrasives (CBN). Semi-analytical and numerical (FEM) methods combined with innovative experimental procedures have been used to develop the models. Thus the principal achievements of the project are the different models developed for suitable for exploitation in production form grinding. The main outcome are listed below: a) Development of new test method (wedge grinding test -WGT) for thermal damage related grindability characterization of hardened alloy steels and tool steels. b) New models for the estimation of grinding forces valid for conventional and creep feed mode based on grinding conditions, grinding wheel topography and work material properties c) New models for the estimation of heat partition in form grinding and hence for the estimation of grinding temperature taking into account the cutting fluid used d) Methods for estimating the form specific temperature concentration factor and methods to smoothen this effect e) Models for the evaluation of residual stresses in grinding f) Models for grinding wheel topography and surface finish in grinding as a function of grinding conditions and dressing parameters The force, temperature and residual stress have been verified through laboratory experiments. The temperature rise in flute form grinding of HSS M2 was computed using FEM and verified under production conditions. Similarly, trial grinding of shoulder forms in steel EN39B under production conditions has validated the proposed design procedure for grinding cycle based on damage specific temperature criteria. This model based design procedure is modularized, allowing for variations in grinding efficiency (through specific energy) and specified temperature-damage criteria. The output advises the designer on the maximum allowable value of infeed rate to be applied so as to not exceed the specified temperature. This procedure is available in Manual Input format with an accompanying hard copy 'Design Manual' providing advisory notes and 'Design Charts', or in PC format based on the MicroSoft Office platform. The model for grinding forces as a function of wheel dressing conditions, work material property and grinding conditions can be downloaded from the following website: http://www.mme.tcd.ie/~jbadger/grasp/grasp.html. Searching for OpenAIRE data... There was an error trying to search data from OpenAIRE No results available
