Analysis and Minimization of Blow Holes Using DMAIC Approach

The present work deals with minimization of sand casting defects in a foundry industry. DMAIC approach is justified when root cause of defect is not traceable. At present, global and competitive environment, foundary industries need to perform efficiently with minimum number of rejection in their manufacturing products. For better improvement in the casting quality, first of all finding the root causes of occurrence of defects blow hole in the casting process and taking necessary step to reduces defects and hence rejection in casting. Six sigma is more than a quantitative statistical measure of processes; it embraces every aspect of work, using a disciplined, fact based approach of problem-solving. Many time defects occur due to variation in the process parameter which are very difficult to detect. In the present work the metal casting process is analysis and minimised by using DMAIC (Define, Measure, Analysis, Improve, and Control) approach. Through a case study in a medium scale faundary, the present work formulate a comprehensive strategy of six sigma in indianfoundary. This study has significantly increase the efficiency of foundry industry and reduce scrap and waste in sand casting process which improve the production efficiency.A number of experiments are carried out to validate the results which indicate that the cost of experimentation will be less, in comparison to the gain or profit of the company. The results achieved shows that the rejection due to blow hole defects has been reduced from 5.83% to 2.04% which saved the cost of Rs 23828/- monthly (for continuous four months), in a turnover of 60 lakhs.