Precision internal grinding of bearing steel based on the state control of oxide layer with electrolytic in-process dressing

The oxide layer state directly relates to the grinding efficiency and machining quality in electrolytic in-process (ELID) grinding. However, no proper and detailed information has been found about internal grinding by controlling the state of the oxide layer. Therefore, in this investigation, some experiments have been conducted based on the active control of the oxide layer state to study internal grinding performance and ground surface qualities. The experimental comparison with the traditional ELID grinding has been carried out to prove the advantages of the proposed method in dynamic equilibrium. The influences of the grinding and electrical parameters on the workpiece surface quality, force characteristics and material removal rate of internal machining of bearing steel have been investigated in detail. The experimental results show that the new method can realize a stable internal grinding process even with finer abrasive wheels of W10 and W2.5.

► Dressing current as a sign of the state of the oxide layer. ► The superposition of big and small pulse can achieve periodical electrolysis. ► Periodical electrolysis can adjust the state of oxide layer. ► The proposed ELID can realize a stable internal grinding process.