Papers by Keyword: Grinding Wheel Topography

Abstract: At present, CNC grinding efficiency has been low, the main reason is the grinding tool-grinding wheel. The service life of grinding wheel is an important element for restricting the grinding efficiency, and the main reason for affecting grinding wheel service life is the distribution of the grinding wheel grits. The chaotic distribution of grinding wheel grits reduces grinding efficiency. This paper analyzes the physical and chemical characteristics of the CBN grits, puts forward that through adding the magnetic field method in the process of electroplating wheel, changes the position and posture of CBN grits on the grinding wheel base body, and makes its an orderly distribution. And thus this method greatly improves the grinding efficiency and service life of the electroplating CBN grinding wheel.

Abstract: The topography of a grinding wheel can be obtained quickly and exactly through applying the computer vision method to detect the wheel topography. However, the application of computer vision in detecting wheel topography is restricted due to the contradiction between vision field and resolution while using traditional computer vision detecting method. In the present paper, the 3D topography of a diamond grinding wheel was reconstructed by combining image mosaic technique, corner detection algorithm, image matching algorithm and image fusion algorithm. The image mosaic technique was found to be effective in solving the contradiction between visual field and resolution and rapidly obtain high resolution image of the wheel topography in a wider range of vision field, thereby providing a valuable reference for quantitative evaluation of the performance of grinding wheels.

Abstract: In this paper, on the influence of different dressing methods, such as elliptical ultrasonic vibration, on the grinding wheel bonded delta, the morphology of abrasive grains of wheel, the protrusion height and the grinding wheel topography was studied by experiment. The experiment shows that the abrasive grains of grinding wheel surface dressed by elliptical ultrasonic vibration are great in protrusion height and trench depth, and the bonded delta grain after grinding is narrow, short, and irregular with significant reduced semi-surrounded area compared with by ordinary dressing method. The abrasive grains of metal-bonded diamond grinding wheel surface dressed by elliptical ultrasonic vibration are basically intact, and due to the high-speed collision between abrasive grains, local micro-break is easy to occur on the abrasive grains to form multiple micro-cutting edges. The abrasive grains of grinding wheel surface dressed by ordinary dressing method are fractured and broken, while that of resin-bonded grinding wheel surface have a high ratio to be loose and shedding. For the metal or resin-bonded grinding wheel surface dressed by elliptical ultrasonic vibration, its material removal mechanism may primarily be the removal of bonding ductility and the fine-crushing of abrasive grains; for the metal-bonded grinding wheel surface dressed by ordinary method, its material removal mechanism may primarily be the fracture and break of abrasive grains, secondly be the fracture of bonding agent; and for the resin-bonded grinding wheel surface, its material removal mechanism may mainly be the looseness and shedding of abrasive grains caused by the fracture of bonding agent, secondly be the fracture of abrasive grains. Compared with ordinary dressing method, elliptical ultrasonic vibration dressed abrasive grains are dense at shaft and sparse in periphery, with a large quantity of static effective abrasive grains, great protrusion height and an excellent nature of contour.

Abstract: In this paper, topography feature of the diamond grinding wheel under the diamond stylus elliptical ultrasonic vibration assisted dressing was studied experimentally. The results indicate that: the increase in dressing power of elliptical ultrasonic vibration will result in the increase in amplitude, and that can increase abrasive protrusion height of the dressing grinding wheel, and also increase the depth of chip pocket. With the increase of feed rate, surface peak and valley values of elliptical ultrasonic vibration dressing grinding wheel increase, that is the average protrusion height of abrasive grain increases. With the increase of dressing depth, surface peak and valley values of elliptical ultrasonic vibration dressing grinding wheel increases, while the number of static effective abrasive grain reduces. In comparison with the ordinary dressing grinding wheel, elliptical ultrasonic assisted dressing in the same parameters can bring about more static effective abrasive grain , more uniform abrasive distribution, a higher abrasive protrusion height and more chip space.

Abstract: White light interferometer was employed to measure the surface topography of 60# and 120# alumina grinding wheel. The correlation of wheel topography and its performance was characterized through the three-dimensional (3D) surface characterization parameters of “Birmingham set”. Birmingham parameters were used to characterize the performances of grinding wheel, in items of grain density, grain shape and grain sharpness. The effects of sampling interval on the 3D surface parameters were analyzed and the optimal sampling interval was selected to calculate the 3D surface parameters.

Abstract: This paper describes the experimental results of the relationship between grinding wheel topography and grinding chatter and surface waveness on the precise surface grinding machine. The inner relationship between the grinding chatter and grinding surface waveness has been analyzed. The experimental research results show that the grinding depth is a main factor which affects grinding chatter and grinding surface waveness on the grinding surface. Thus a further exploration has been made in the formative mechanism of grinding chatter and grinding surface waveness.

Abstract: In this paper the geometry of the grinding wheel effective topography is analyzed. Existing and newly developed abrasive grain geometry models are investigated. Further, different abrasive distribution systems are developed and the grinding wheel surface is generated. The 3D stereomicroscopy at the Scanning Electron Microscope offers the opportunity to measure a three-dimensional profile of the grinding wheel. Hence, the investigations of the real grinding wheel surface can be used as a verification of the developed surface model. Abbott-Firestone-Curves are used as a comparison of the model based topography and the real grinding wheel surface. The variation of the grain geometry and distribution offers the opportunity to adapt the simulation to the grinding wheel specification.

Abstract: Measurement of the grinding wheel topography and its change in machining process is important for revealing the grinding principle of high-temperature brazed mono-layer super-abrasive grinding wheel. A new approach of measuring grinding wheel topography based on binocular stereovision is presented. Firstly, the binocular images are achieved while the optical axes of the two cameras are parallel, and a corner reflection function algorithm is applied to detect corners. Secondly, in order to get matching corners, optimal matching template is obtained by matching curves. The experimental results show that the sequential similarity matching operation with optimal template has advantages of high accuracy, and less error matching. Finally, the height of the corners is obtained by calculating their parallax on left and right image, and the height error is less than 5%.

Abstract: Aiming at the existent problems in the application of high efficiency grinding, some countermeasures are put forward to further exploit its potential, including the topography optimization design for high efficiency grinding wheel and cooling enhancement technology with jet impingement in grinding zone. The optimization model advanced here can be used to optimize the grinding wheel topography for different grinding processes with the minimum specific grinding energy. The cooling enhancement technology employed in creep feed deep grinding experiment of titanium alloy shows remarkable cooling capability. It is able to steadily control the temperature on workpiece surface at an extremely low lever under 100°C,when the workpiece is seriously burn with the conventional coolant supply. Further studies on the combination of these two countermeasures will not only enable us to increase the available material removal rate to a new lever but also solve the workpiece burn problem for those difficult-to-machining materials in high efficiency grinding.