Key Engineering Materials Vol. 329

Abstract: A thermal model has been implemented in industrial operations where reliability and robustness are important. To fully exploit the potential and usefulness of the thermal model it is necessary to tune the model to accommodate a wide range of wheel / workpiece combinations whilst also satisfying different quality criteria. Implementation is relatively simple and thermal damage to the workpiece can be avoided in most grinding operations. The monitoring process can also be used to aid in optimising dressing intervals or as a tool to identify deteriorating conditions. It is important to understand how to develop and implement strategies to satisfy different user needs. This paper reports on issues associated with tuning the model. Guidance is provided to assist with implementation of the thermal model either as a stand alone monitoring tool or as a fully integrated embedded feature of an intelligent control system. The paper has been prepared in response to queries on this matter from industrial practitioners.

Abstract: The surface roughness in centerless grinding is mainly affected by the many process parameters. For decreasing the surface roughness, the control of grinding parameters is very important. This paper deal with the analysis of the process parameters such as height of centers, tilting angle of the regulating wheel, speed of the regulating wheel, developed based on Taguchi method and response surface method. The effect of grinding parameters on the surface roughness was evaluated the utilization of the response surface model was evaluated with constraints of the surface roughness.

Abstract: The material removal in grinding involves rubbing, ploughing and cutting. For grinding process monitoring, it is important to identify the effects of these different phenomena experienced during grinding. A fundamental investigation has been made with single grit cutting tests. Acoustic Emission (AE) signals would give the information relating to the groove profile in terms of material removal and deformation. A combination of filters, Short-Time Fourier Transform (STFT), Wavelets Transform (WT), statistical windowing of the WT with the kurtosis, variance, skew, mean and time constant measurements provided the principle components for classifying the different grinding phenomena. Identification of different grinding phenomena was achieved from the principle components being trained and tested against a Neural Network (NN) representation.

Abstract: This paper describes the structure, content and relations employed in the development of an intelligent grinding database. The intelligent database has been constructed in MS Access with Visual Basic support code. The database was developed as an integral feature of an intelligent grinding assistant (IGA  ). The IGA  has been implemented and evaluated on a cooperating partners CNC machine tool.

Abstract: To enhance the precision and productivity of ultra precision aspheric surface micro lens, the development of ultra-precision grinding system and process for the aspheric surface micro lens are described. In this paper, an ultra-precision grinding system for manufacturing the aspheric surface micro lens was developed by considering the factors affecting the grinding surface roughness and profile accuracy. This paper deals with the mirror grinding of an aspheric surface micro lens by resin bonded diamond wheel and with the spherical lens of BK7. The optimization of grinding conditions with respect to ground surface roughness and profiles accuracy is investigated by design of experiments.

Abstract: A grain-arranged diamond wheel is developed and grinding performance of the wheel against industrial pure aluminum, one of the most hard-to-grinding materials, is investigated. The developed wheel efficiently ground pure aluminum without adhesion even when general-purpose grinding fluid, Type A3-1, was used. Moreover, wheel wear was not observed during the experiment, and grinding energy was extremely low. By using the developed wheel, a mirror surface can be easily obtained by one-pass surface grinding with very low table speed.

Abstract: The elastic deformation of workpiece acted by grinding force is so large as to make the low machining efficiency and accuracy in the cylindrical grinding of micro parts of which the stiffness is extremely small because of their small diameter. In this study, the perpendicular axis type cylindrical traverse grinding is proposed for the manufacture of micro parts, and the undeformed chip shape in the grinding process is investigated comparing with that in the parallel axis type traverse grinding using generally for manufacture of over small-sized parts. The surface finish and the form accuracy of workpiece by the perpendicular axis type grinding are finer than those by the parallel axis type grinding with the developed micro cylindrical grinding machine.

Abstract: This paper describes influence of work stiffness on grinding accuracy investigated by computer simulations of grinding process for cylindrical plunge grinding. The reliability of simulation program was demonstrated by identification with experimental results. Then, effects of various error causes on grinding accuracy were investigated for different work stiffness. Accuracy of the ground surface is affected in different manners by different error causes. Therefore it is not always true that higher stiffness results in higher accuracy.

Abstract: Grind-hardening was done on Steel AISI 1066 with a conventional surface grinder and a corundum grinding wheel, and research was conducted to probe into structures and properties of the hardened layer under varied depth of cut and cooling conditions. Results show that the hardened layer do not change noticeably in their martensitic structures and micro-hardness, which is ranged between 810
870HV; But when the depth of cut increased or the dry grinding technique is adopted, the concentration of martensites and carbonides becomes lower, while the amount of residual austenites increases, and the completely hardened zone gets thicker. This conclusion serves as an experimental basis for the active control of properties of the grind-hardened layer of Steel AISI 1066.