Grinding Process of Alumina Workpiece with Double Disc Vertical Spindle Grinding Machine

The work has been done in Monzesi S.p.A., an Italian company based in Nova Milanese, Lombardy region, that specializes on designing and manufacturing grinding machines. The aim of this work is to find the right machine setup and combination of parameters to optimize the grinding result and to achieve the desired requirements from the customer. In this case, the customer has requested to machine a ring-shaped disc made from Alumina ceramic (Al2O3) using a vertical axis doble disc grinding machine with rotary table. The workpiece has relatively small dimension with around 40 mm in diameter and 4 mm in thickness. By using the vertical axis doble disc grinding machine with rotary table, it is possible to achieve high production rate of around 50 pieces per minute. The vertical spindle double disc grinding machine has multiple parameters that can be adjusted to achieve the desired machining result, such as the grinding wheel openings, grinding wheel speed, and rotary table speed. Whereas there are other parameters that has been defined by the company’s supplier to ensure the best performance, such as the grinding wheel specification, the lubricant type and flow, and the dressing tool. The customer requirements of the machined workpiece are to ensure the thickness, flatness, and surface finish of the workpiece is within the tolerances: 3.92 – 3.96 mm for the thickness, < 5 &#956;m for the flatness, and 0.15 – 0.30 &#956;m for the surface finish. The measurement is done in the company’s measurement lab as well as in different measurement facility and the customer-owned facility to guarantee the precise measurement results.