Optimization of Gear Blank Casting Process by Using Taguchi's Robust Design Technique

This study demonstrates optimization of the gear blank casting process by using Taguchi’s Robust Design technique. The metal casting process involves a large number of parameters affecting the various casting quality features of the product. Some of the parameters are controllable and some are uncontrollable, e.g., noise factors. In order to optimize the process, six control factors — namely, clay content, moisture content, ramming, sand particle size, metal fluidity, and gating design — were selected. Each process factor was considered at three levels. The quality characteristic selected was casting defects. The reduction in the weight of casting as compared to the target weight was taken to be proportional to the casting defects. An orthogonal array was constructed for the six factors undertaken, and performing 18 sets of experiments generated the data. The weights of the finished castings were obtained and signalto-noise ratios were calculated by using the nominal best approach of parameter design. The average values of signal-to-noise ratios for each factor at three levels were calculated and were plotted on the graph. Considering the maximum signal-to-noise ratios from the graph, the optimum levels of process factors in the type of task considered were obtained. A validation experiment was performed using the levels obtained. The weight of the castings produced was found to have a value close to the target value