Roman Wdowik

Coordinate Measurements of Geometrically Complex Ceramic Parts

The article presents the results of numerical and experimental investigations concerning contact coordinate measurements of complex ceramic parts made of Al2O3 and ZrO2 based ceramic materials in different states. The investigated parts were manufactured by using two machining processes: ultrasonic assisted grinding and conventional grinding. The results of investigations may be used in order to improve the manufacturing process of geometrically complex ceramic parts.

Application of Eddy Current Sensor System and LDV Device for Ultrasonic Vibrations Measurements

The article presents eddy current sensor system in respect to the measurements of vibrations for ultrasonic assisted machining processes. The comparison of eddy current sensor system with laser doppler vibrometer (LDV device) is also presented. The paper concerns the analysis of the influence of the distance between the tool and the sensor on amplitude value, filtering of raw voltage signals in MATLAB and amplitude values presentation for different tools after MATLAB and LDV software analysis. Functionality of two applied devices can be discussed after investigations. Differences in recorded amplitude’s values are also discussed. The examples of measurements and test stand configuration are presented. For better understanding of hybrid machining process, it is important to indicate the possible methods of amplitude measurements and to analyze the results of measurements.

Measurements of Surface Roughness in Ultrasonic Assisted Grinding of Ceramic Materials

The paper presents the results of investigations regarding surface roughness measurements in ultrasonic assisted grinding of selected ZrO2 based ceramic material. There are different results, in the area of surface roughness measurements, presented in the literature. The entry data of hybrid machining process (e.g. grinding wheel type, feed, machining strategy or process variant) may influence these results. The analysis of literature encourages to take up the investigations of surface quality in ultrasonic assisted machining. These investigations may be performed for specific ceramic products and technological tasks which are commonly applied in ceramic machining processes. The knowledge about the machining of ceramic materials in different sintering states is very limited. Based on this finding, ultrasonic assisted and conventional machining processes of ZrO2 based ceramic material in different sintering states were investigated.

A robust design based methodology for investigation of optimal parameters' combination in ultrasonic assisted face grinding

This manuscript presents the results of experimental investigations which have been carried out to investigate the optimal parameter combination that results in the minimum axial process force (PF) in ultrasonic assisted face grinding (UAFG). A diamond grinding tool (diamond drill) was used in these investigations. The UAFG is a hybrid machining process, which has been used for the machining of advanced ceramic materials. The application of ultrasonic assisted grinding (UAG) is still limited, inter alia, because of difficulties during the selection of values for input machining parameters, such as: cutting velocity, feed rate, frequency of vibrations, and mounting torque, which is applied during tool clamping. The ultrasonic assistance provides advantages for the process course if the appropriate combination of input parameters is set on a hybrid/computer numerical control (CNC) machine tool. The PFs on the Ultrasonic 20 linear machine tool are measured using the Kistler 9256C2 dynamometer, and the optimal process parameter combination is calculated using the engineering robust design approach (ERDA).