Exploratory Data Analysis for Achieving Optimal Environmental and Operational Parameter Settings for Making Quality Crossmember Castings

摘要

As an important structural link between the driver and passenger side of an automobile, a crossmember provides mounting locations for suspension components, engine mount, and underbody aerodynamic pans. In order to achieve higher fuel efficiency of vehicles, FCA designed a high-pressure die cast structural aluminum crossmember to reduce the weight of the component while still maintaining the required performance. To ensure its quality, this structural part requires both 100% X-ray inspection and 100% fluorescent penetrant inspection with very strict acceptance criteria. X-ray rejection resulting from gas and shrink porosity plays a significant part in rejection scrap. The design of a front crossmember casting is a complicated process, which involves complex geometry to meet noise, vibration, and harshness requirements, and simulations to develop fluid flow designs. The optimization with respect to geometry design has been addressed by extensive simulations, but the product quality is still heavily affected by defects that are caused by porosity generated in the process. A good part is required to pass both X-ray inspection and fluorescent penetrant inspection. The most vital issue is X-ray rejection scrap for porosity in multiple areas on the body of crossmembers. Using a fully instrumented die casting machine for the manufacturing of this part, FCA has accumulated a large amount of data on the production conditions and related scrap rates. Statistical analysis models were used to make a qualitative analysis of the relationship between scrap rate and the operational parameters of the die casting process. Parameters that affect the scrap rate of the crossmember casting were determined in a previous paper. However, humidity and temperature were not collected in the production data and thus were not included in that research. It is well known that humidity and temperature affect porosity formation in castings.