Ali Zahedi

Modelling of the micro-grinding process considering the grinding tool topography

The micro topography of the grinding tool has a considerable influence on the cutting forces and temperature as well as the tool wear. This paper addresses an analytical modelling of the micro-grinding process based on the real tool topography and kinematic modelling of the cutting-edgeworkpiece interactions. An approximate shape of the abrasive grains and their distribution is obtained from the confocal images, which are taken from the tool surface - determining the grain height protrusion and the probability density function of the grains. To determine the grinding forces, a transient kinematic approach is developed. In this method, the individual grit interaction with the workpiece is extended to the whole cutting zone in the peripheral flank grinding operation. Hence a predictive model of cutting forces and surface roughness in micro grinding of titanium grade 5 is developed. Finally, the simulated forces and surface roughness are validated by the experimental results.

An analytical force and surface roughness model for cylindrical grinding of brittle materials

In this paper, an analytical approach is proposed for the modelling of ground surface and grinding forces in cylindrical grinding of ceramic materials. The model incorporates the near-actual distribution of cutting grains over the grinding wheel surface and a kinematic approach for the engagement of the grains with the workpiece surface per grinding parameters and conditions. To interpret the stochastic engagement of arbitrary grains with the workpiece, and to distinguish the dominant material removal mechanism, fracture mechanics of single-grain indentation is applied. The approach based on the fracture mechanics accounts for grain size and geometry and material properties. The results of a previously performed research on single-grain scratch tests are taken for interpreting force and workpiece surface characteristics. Without losing generality, the model was applied to a cylindrical plunge grinding of an alumina ceramic. The experiments show qualitative agreement of model predictions with the experimental force and ground workpiece topography.

Laser-Profiling of Metal-Bonded Diamond Grinding Wheels

Conditioning challenges of superabrasive grinding wheels cause a barrier to the extensive applications of these tools. These concerns are more pronounced in the case of conditioning of metal-bonded superabrasive grinding wheels owing to their high bond hardness. Laser ablation has been used as a promising method for conditioning of such tools. In this research an ultrashort pulsed laser was used for efficient profiling of metal-bonded diamond grinding wheels. In order to assess the laser-profiling technique, the experiments were aimed to generate precise profiles which are rather too difficult or impossible to generate with conventional methods. Convex and concave profiles with minimum radius of about 20 μm and 40 μm, respectively are produced successfully via laser conditioning.