Study on the Effect of Standoff Distance on Processing Performance of Alumina Ceramics in Two Modes of Abrasive Waterjet Turning Patterns

Abrasive waterjet (AWJ) turning is an emerging technology, which plays an important role in machining cylindrical parts with the distinct advantages of negligible thermal effects and extremely low cutting force. This paper presents an experimental study of abrasive waterjet turning (AWJT) of Al2O3 ceramics. The machining process and performance in terms of the depth of penetration (DOP), surface roughness (Ra) and actual impact angle (β) are discussed to understand the effect of standoff distance (SOD) on the processing performance at two different turning modes. Based on the results of these investigations, there is a significant change of DOP and Ra at different SOD in radial mode turning and the optimal SOD of gaining maximum DOP and the minimum Ra is about 5.5mm.However, the DOP is nearly independent on the SOD in offset mode turning. Smaller Ra and DOP can be obtained in offset mode. Furthermore, the results indicate that the roundness error of cylinder parts is probably improved with the proper SOD interval in radial mode turning and it is suitable for machining cylinder part with considerably different radial size. The offset mode turning as the next operation after radial mode turning is recommended to process workpiece with excellent roundness. In this way, by understanding the effect of SOD on processing alumina ceramics, the paper establishes a good basis for developing strategies for optimizing processing parameters in order to generate the desired part geometry and achieve better surface quality.