STUDY OF SURFACE ROUGHNESS OF GROUND CERAMICS BY VIBRATION SIGNAL ANALYSIS
Pedro de Oliveira Conceição Junior1; Danilo Marcus Santos Ribeiro1; Thiago Valle França1; Paulo Roberto de Aguiar1; Eduardo Carlos Bianchi1; Ana Claudia Rodrigues2; Marcelo Marchi3
1 Universidade Estadual Paulista - UNESP, Faculdade de Engenharia, Campus Bauru, Departamento de Enge; 2 Universidade Estadual Paulista - UNESP, Faculdade de Engenharia, Campus Bauru, Departamento de Enge; 3 Universidade Estadual Paulista - UNESP, Faculdade de Engenharia, Campus Bauru
doi:10.20906/CPS/COB-2015-0102
Resumo
Grinding is widely used in finishing of advanced ceramics; however, some parameters involved in this process, such as vibration and increased cutting forces are directly related to the surface quality of the parts. Monitoring the grinding of ceramics using the vibration signal is presented as an alternative for the diagnosis of the workpiece surface. This paper has the objective of studying the vibration signal, and looking for the best parameters that could be related to the surface roughness in the finished workpieces of ceramics. A surface grinding machine with diamond grinding wheel and alumina ceramic workpieces was used. The vibration signal was measured by an accelerometer and collected by the oscilloscope, using 2 MHz of sample rate. Tests were conducted at different depths of cut, adopting two different feed speeds (vw), which allow for low to severe grinding conditions. The surface roughness Ra of each finished workpiece was measured at four points along its surface, using a portable roughness measurer. The digital signal processing was performed by applying computational tools on each cutting phase, and then the results with surface roughness were compared. It was found that the more severe the grinding conditions the higher the surface roughness and vibration values. For higher workpiece speed vw, lower roughness values and higher vibrational activity were observed. The higher roughness values and lower vibration activity were observed for the lowest cutting speed used. Surface roughness remained generally within the range of acceptable values. In conclusion, vibration and roughness have an upward trend over the cutting depths and both have opposite amplitudes at each vw. Thus, a good surface quality of the workpiece can be achieved even with a higher vibration level.
Palavras-chave: Grinding; Surface Roughness; Vibration Signal; Advanced Ceramics; Monitoring