Grinding is one of the essential manufacturing processes for producing brittle or hard materials-based precision parts (e.g., optical lenses). In grinding, a grinding wheel removes the desired amount of material by passing the same area on the workpiece surface multiple times. How the topography of a workpiece surface evolves with these passes is thus an important research issue, which has not yet been addressed elaborately. The present paper tackles this issue from both the theoretical and the experimental points of view. In particular, this paper presents the results of experimental and theoretical investigations on the multi-pass surface grinding operations where the workpiece surface is made of glass and the grinding wheel consists of cBN abrasive grains. Both investigations confirm that a great deal of stochasticity is involved in the grinding mechanism, and the complexity of the workpiece surface gradually increases along with the number of passes.
Ti6Al4V alloys are difficult-to-cut materials that have extensive applications in the automotive and aerospace industry. A great deal of effort has been made to develop and improve the machining operations of Ti6Al4V alloys. This paper presents an experimental study that systematically analyzes the effects of the machining conditions (ultrasonic power, feed rate, spindle speed, and tool diameter) on the performance parameters (cutting force, tool wear, overcut error, and cylindricity error), while drilling high precision holes on the workpiece made of Ti6Al4V alloys using rotary ultrasonic machining (RUM). Numerical results were obtained by conducting experiments following the design of an experiment procedure. The effects of the machining conditions on each performance parameter have been determined by constructing a set of possibility distributions (i.e., trapezoidal fuzzy numbers) from the experimental data. A possibility distribution is a probability-distribution-neural representation of uncertainty, and is effective in quantifying the uncertainty underlying physical quantities when there is a limited number of data points which is the case here. Lastly, the optimal machining conditions have been identified using these possibility distributions.
Rotary diamond dressers are one of the most widely used dressers for the dressing of vitrified grinding wheels. In this study, we develop a relatively comprehensive dressing mechanism for the rotary diamond dresser that takes into consideration the relationship between the dressing conditions and the dressing trajectories of diamond grits formed on the working surface of a grinding wheel. The dressing mechanism can be used to determine the dressing performance, i.e., whether or not the diamond grits come in contact with the entire circumferential surface of the grinding wheel, known as complete dressing. A computer-aided simulation of the dressing process is developed to visualize the dressing trajectories formed on the working surface of the grinding wheel for a given set of dressing conditions, i.e., the velocity ratio of the rotary diamond dresser to the grinding wheel, up-cut or down-cut dressing, and single-pass or multipass dressing. Using the simulation process, the maximum feed speed of the rotary diamond dresser in single-pass dressing and the minimum number of passes in multipass dressing required to realize complete dressing are examined.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.