Analysis of damaged aero-engine blades

Findings of the analysis of damaged compressor blades (Sl. Nos. 6, 12 and 20) of an aero engine are presented in this report. Examination revealed that all the three blades had foreign object damage (FOD) on the leading edge. The damages were caused due to impact of hard object(s) on the concave surface of the airfoil. Nature of damages and compositional analysis of the smeared material at the impacted regions revealed that the foreign object(s) was metallic in nature and it was rich in iron (Fe), and the object was probably plated with cadmium (Cd). Analysis showed that the nature of foreign object was same/similar in all the 3 blades. Considering the shape of the FOD on the blades and elements present in the smeared material, it appears that the FOD was probably caused by a steel fastener plated with cadmium