Suspension-type abrasive water jet machining of slot on nitrile butadiene rubber: A preliminary study

Abstract

Nitrile butadiene rubber (NBR) bushings, having thickness of 10–20 mm, are widely used in mining equipment such as positive displacement motor or mud motor stators. The most common methods used for batch production of these components are compression and injection molding followed by milling. It is very difficult to transfer the used molds to other working units, which necessitates an alternate method for manufacturing such components. Out of available non-conventional machining methods, the abrasive water jet (AWJ) machining methods are a better option due to less burr formation and absence of heat-affected zone. The present study focuses on the machining of NBR at room temperature, using a non-conventional machining method, namely, suspension-type abrasive water jet (AWJ) machining. The objective is to verify if slots could be produced using AWJ machining on 10 mm thick NBR samples. The preliminary results confirmed that the suspension-type AWJ machining is able to produce the slots in 10 mm thick NBR samples with the absence of cracks near the machined kerf profile. Wavy edges were observed in the machined kerf profile; however, further investigation would be required to find out the optimum values of the process parameters to get the waviness-free kerf profile.