A data-driven analysis of Ti-based alloys for aircraft landing gear beams and future directions

Titanium alloys find themselves in diverse aerospace applications owing to their low density, superior combination of various mechanical properties, coupled with excellent corrosion resistance. Although, from a metallurgical perspective, it is imperative to zoom into one or two classes of titanium alloys, it becomes challenging to methodically arrive at an optimum selection of a specific alloy or alloys from the data among the apparently competing gamut of alloys for an intended application requirement/s. There is ample data available in the open literature on several titanium alloys under various processing conditions to suit the needs of a particular application like landing gear requiring high strength, high toughness, fatigue resistance, and corrosion resistance. We analyzed the available relevant data on several of these titanium alloys from the open literature. Advanced statistical analysis, namely, cluster analysis (CA), principal component analysis (PCA), and multiple-attribute decision making (MADM), were applied to hear the voice of the data. Both objective (Shannon's entropy method) and subjective methods with metallurgical insights were adopted to evaluate the weights of various properties. PCA and CA not only consolidated the MADM ranks of the alloys but also grouped similar alloys. The rank assigned by several MADMs viz. selective additive weighting (SAW), WEDBA (weighed Euclidean distance-based approach), TOPSIS (Technique for the order of preference by similarity to ideal solution), and others were consistent. The investigation highlights similarities (and differences) across several grades/variants of the alloys, suggests potential replacement or substitute for the existing alloys, and also provides directions for improvement and/or development of these alloys to ensure robustness and reliability. This methodology further demonstrates that it is possible to try different weightage scenarios and decide on the optimum alloy(s) for the specific intended application(s).