Análise da integridade da superfície e do desvio dimensional de aço rolamento pela técnica da impedância eletromecânica após retificação cilíndrica de mergulho

Abstract

Among the peculiarities of grinding process with conventional abrasive grinding wheels high specific cutting energy highlights because it is responsible for most of heat generated to be transferred to workpiece, thereby potentializing the occurrence of thermal damages and distortions to the workpiece. For this reason, monitoring of workpiece surface integrity is crucial to ensure the quality of the finished product, especially using non-destructive methods. Among these methods, the electromechanical impedance (EMI), for example, poses as promising and reliable technique to monitor the integrity ground components. In this context, this work aims to investigate the applicability of the EMI technique as a tool for monitoring the surface integrity and dimensional deviation of SAE 52100 steel samples submitted to the plunge cylindrical grinding process with aluminum oxide grinding wheel. The cutting parameters were: sparkout time (0 and 5 s), feed rate (0.75 mm/min and 1.50 mm/min) and workspeed (15 m/min and 30 m/min). As output variables, amplitude roughness parameters (Ra, Rq, Rvk, Rk and Rpk) and morphological space (Rsk, Rku), microhardness below the machined surface, dimensional deviation, and the electrical measurements of the process. The results showed that at lower feed rate and sparkout time strongly affected on the reduction of surface roughness and dimensional deviation. On the other hand, the increase in the workpiece microhardness at about 30 μm below the machined surface was influenced primarily by the high workspeed. With respect to the analysis of the damage indexes from the EMI signals a strong correlation between the CCDM index and the roughness Ra (90 to 95 kHz) and microhardness (55 to 60 kHz) was noticed. For the dimensional deviation the correlation was observed either with the CCDM index (25 to 30 kHz) and by RMSD5 in the range of 60 to 65 kHz.