Optimization of Casting Defects in Aluminum Alloy Wheels through Quality Control Estimation

Vaseem, Prof. Vaibhav Khurana

In automotive industry several kinds of alloys are used for manufacturing the components. With the increasing use of aluminum wheels in automotive industry, the aluminum foundry industry had to focus on the quality and reliability of the components. The quality of the components can be increased by monitoring the defects and evaluating it.

Aim of this study is to drop the casting defects with the help of quality control tool. This study shows the systematic approach to find the root cause of major defects in aluminum castings using defect diagnostic approach as well as cause and effect diagram. Casting defect analysis is carried out using techniques like historical data analysis, cause-effect diagrams, design of experiments and root cause analysis. Data from X-ray inspection (Radiographic Inspection) have been collected along with the production parameter data. Using Pareto chart major defects in the aluminum castings were noted. The major defects for the rejections during production were identified as shrinkages, inclusions, porosity/gas holes and cracks. Each defect is studied thoroughly and the possible causes for the defects are shown in Fishbone Diagrams (Cause Effect Diagrams). As the shrinkages mainly occur due to lack of feed ability during the fluid flow the stalk changing frequency is noted along with the shrinkages defects and a relation is drawn between them. As hydrogen forms gas holes and porosity in the aluminum castings the amount of hydrogen present in the molten metal is studied by finding specific gravity of the samples collected. The molten metal temperature affects the amount of the hydrogen absorbed by it. .So the effect of molten metal temperature on the specific gravity of the sample collected have been shown in a graph and the optimum value for molten metal temperature was found out.