Papers by Keyword: Wheel Topography

Abstract: Visualization of work surface topography through simulations is very challenging task in grinding process due to the complexity of wheel-work interactions with a very high number of cutting points (grits). Kinematic mapping of abrasive grits on a three-dimensional wheel topography enables the evaluation of ground surface topography through simulations. In this paper, a method for generating the ground surface topography based on wheel specifications is presented. Abrasive grits size, abrasives volume percentage and their nature of distribution on the wheel surface are considered in the modeling and visualization of wheel topography. The simulation results of ground surface topographies prove the feasibility of the developed method.

Abstract: Laser triangulation was used to measure the topography of vitrified CBN wheels and optimum sampling interval was obtained by comparing measuring results with different sampling intervals. Four evaluation indexes including the mean protrusion height of abrasive grains Hm, the standard deviation of grain protrusion height Hv, the standard deviation of the distance between two adjacent grains Dv and the number of micro cutting edges per square millimeter Nm were put forward to assess wheel topography and grinding performance. These indexes were verified to be effective by comparing 3D topography of newly manufactured wheel and dressed wheel.

Abstract: Grinding is an important method for precision machining and ultra-precision grinding. It is used to generate parts with high surface finish, high form accuracy and surface integrity. In recent years, grinding technology in precision machining and ultra-precision machining of ceramics, glass and high-strength alloys and other hard materials has been applied widely. Grinding process is complex, once known as "black processing technology." Computer simulation is an important method to research the grinding mechanism and optimize the grinding process parameters. Especially in recent years as the development of computer calculation speed, the improvement of computer graphics theory and the gradual maturity of artificial intelligence technology, experts and scholars whose research subject related grinding had done a lot of work on grinding simulation. This paper gives an overview of the current state of the art in simulation of grinding processes: Physical simulation (material removal mechanism, grinding force, grinding temperature, etc.) and geometrical simulation (surface topography and surface integrity) are taken into account, and outlined with respect to their achievements in this paper. Furthermore, the capabilities and the limitations of the presented simulation approaches will be exemplified.

Abstract: Grinding performance is evaluated mainly in terms of specific grinding energy. The number of active grits per unit area and their slope is considered as the two grinding wheel topographical key parameters for studying grinding performance. To provide a view on how various parameters influence specific energy and the importance of wheel topography and grit workpiece interaction, a specific grinding energy model is developed. Inputs to this model are workpiece parameters, grinding process parameters, and, in particular, the grinding wheel topographical parameters. This model has been validated by experimental results. The theoretical values considering the complexity of the grinding process reasonably compare with the experimental results. The effect of number of active grits per unit area and their slope on specific grinding energy and then metal removal mechanism is investigated. The results revealed that the number of active grits per unit area has less effect on specific grinding energy than grits slope.

Abstract: Simulation of wheel surface topography is one key aspect of modeling the grinding process. A three-dimensional wheel topography model not only makes the simulated wheel topography more close to the real situation, but also benefits evaluation of wheel machinability and wears condition. This paper presents a physical model for simulation of three-dimensional wheel surface topography. Wheel structural components, grain shape, angle distribution of cutting edges, and the binding materials are considered in the model. Feasibility of the model is indicated by the simulation examples.

Abstract: The Large-grit bronze-bonded diamond grinding wheel was shaped employing a diamond dresser with elliptic ultrasonic vibration assistance, to solve problems such as high cost, low dressing speed and low accuracy. And the truing and conditioning performance of this new method was discussed for its effectiveness. Experimental results showed that the roundness error of elliptic vibration dressed diamond grinding wheel is less, and the bond tail was cut shorter and the chip capacity became larger than that of mechanical dressed one. The SEM observation showed for the present dressing method the material removal mechanism is ductile removal of bond material and micro breakup of gains and this method can perform truing of large-grit diamond grinding wheel as well as conditioning in one step.

Abstract: The experimental research on CBN grinding wheel mechanical dressing assisted by ultrasonic vibration was carried out. Experimental results showed that ultrasonic vibration dressing is capable to improve surface topography and roundness of CBN wheel as other untraditional dressing methods. Compared with traditionally mechanical dressing, the counts of static effective grains of CBN grinding wheel dressed assisted by ultrasonic vibration increased clearly and it had clear relationship with the acoustic parameters and the dressing lead. The grains had a large protrusion height and kept good integrity after ultrasonic dressing. The technology of vibration dressing is able to prepare precisely the CBN grinding wheel.

Abstract: Computer simulation is an important method to research the grinding mechanism and optimize the grinding process parameters. Especially in recent years as the development of computer calculation speed, the improvement of computer graphics theory and the gradual maturity of artificial intelligence technology, experts and scholars whose research subject related grinding had done a lot of work on grinding simulation. This paper describes the main contents grinding of the grinding simulation research work made in recent years. Include some of the key research results of the present grinding simulation, the major difficulties in grinding simulation and the research trends are summarized in this paper.

Abstract: The topography of the grinding wheel has a profound effect in analysis and predicting the finished surface roughness. In this paper, the statistical analysis is applied to establish a distribution function of the grain protrusion heights, and the 3-D simulating topography of grinding wheel will be identified. Through experiments, the generated grinding wheel topography is effective in predicting the finished surface roughness.