Optimization of Foundry Parameters for Reducing Casting Defects

Production of casting involves various processes like pattern making, moulding and assembly, core making and melting etc. A casting defect may be result of a single cause or a combination of causes. The single castings have one or more defects. These can be minimized by taking corrective actions in the tools like pattern, mould making, core making and melting process. This paper presents a systematic procedure to identify as well as to analyze major casting defects carried out at Bharat Fritz Werner, Bangalore, India. High casting reject levels, both internal and customer returns have a considerable adverse effect on productivity, delivery performance, customer satisfaction and employee moral. Diagnostic study carried out on Castings revealed that the contribution of the four prominent defects in casting rejections are blow hole, shrinkage, mismatch, and oversize. It was noticed that these defects are frequently occurring at particular locations. So it preferably necessary to reduce it as much as possible by appropriate analysis of the defects which includes the root cause analysis so that actual reasons behind occurring the defects can be find out to make the corrective action. Outcome of the validation trials showed substantial reduction in rejection of castings. This study aims to implement a novel approach to improve the quality (reducing the defects) of a foundry by Lean Six Sigma methodology.