Targeted material design of flyash filled composites for friction braking application by non-linear regression optimization technique

Targeted material design (TMD) following combinatorial engineering approach based on experimentally determined performance defining attributes (PDA) of a series of heterogeneous friction-composites is attempted via non-linear regression optimization (NLR-OPT) technique. The four key PDAs have been rigorously evaluated on a Krauss friction testing machine. The four selected performance defining attributes (PDA) are performance-friction, wear, friction-fade and friction-recovery. Based on the performance data two target-composite formulations are designed adhering to friction-maximization norms. The theoretically obtained formulation designs for a target set of PDA were later validated by fabricating actual composites followed by their performance assessment on identical testing set-ups and test-regulation. The two targeted composite formulations were also replicated for flyash derived cenospheres in addition to the raw flyash based composites. Finally, the deviations in PDA are critically analyzed from material composition point of view and the adopted approach gives rise to minimal deviation from the magnitude of theoretically estimated PDA. The study has successfully demonstrated that non-linear regression technique based optimization for targeted material design of heterogeneous composites with multiple performance goals may prove to be a sound and viable engineering approach for material designers.