Experimental Study of Machining of Smart Materials Using Submerged Abrasive Waterjet Micromachining Process

Smart materials are new generation materials which possess great properties to mend themselves with a change in environment. Smart materials find applications in a wide range of industries including biomedical, aerospace, defense and energy sector and so on. These materials possess unique properties including high hardness, high strength, high melting point and low creep behavior. Manufacturing of these materials is a huge challenge, particularly at the micron scale. Abrasive waterjet micromachining (AWJMM) is a non-traditional material removal process which has the capability of machining extremely hard and brittle materials such as glasses and ceramics. AWJMM process is usually performed with nozzle and workpiece placed in air. However, machining in the air causes spreading of the waterjet resulting in low machining quality. Performing the AWJMM process with a submerged nozzle and workpiece could eliminate this problem and also reduce noise, splash, and airborne debris particles during the machining process. This research investigates Submerged Abrasive Waterjet Machining (SAWJMM) process for micromachining smart ceramic materials. The research involves experimental study on micromachining of smart materials using an in-house fabricated SAWJMM setup. The effect of critical parameters including stand-off distance, abrasive grain size and material properties on the cavity size, kerf angle and MRR during SAWJMM and AWJMM processes are studied. The study found that SAWJMM process is capable of successfully machining smart materials including shape memory alloys and piezoelectric materials at the micron scale. The machined surfaced are free of thermal stresses and did not show any cracking around the edges. The critical process parameter study revealed that stand-off distance and abrasive grit size significantly affect the machining results.