An organizational design of experiments statistical approach toinvestigate the effect of extrusion process manufacturing on themechanical behavior of an aluminum alloy

摘要

The purpose of this investigation was to utilize a statisticalorganization design of experiments method to analyze and evaluate theinfluence of the extrusion process manufacturing parameters on somegiven mechanical properties for an aluminum alloy containing lithiumwith a given composition and post-extrusion thermal processing. Thiswould assist in determining the necessary human resources required forthe manufacturing, and also the required level quality control duringthe manufacturing. The statistical strategy was to analyze and determineif variations in specific extrusion processing variables or parametershad a statistically significant effect on some given mechanicalproperties such as yield strength; ultimate tensile strength, andductility. The layout for the organizational design experiment consistedof two extrusion temperatures and two extrusion geometries. The layoutalso included six cross section areas nested in two extrusiongeometries. Thus, the design of the experiment was a mixture of a nestedstructure and a factorial structure, i.e., a nested factorial design.This design included interactions crossed between the extrusiontemperature and the extrusion geometry, and the extrusion temperaturewith the cross sectional area. Thus there was a possibility of twelvedifferent treatment combinations that made up the design of experimentsmethod. It was found that the extrusion geometry was at least 95%statistically significant with respect to the mechanical properties ofinterest and that the extrusion temperature was not significant at thislevel