METALLURGICAL FAILURE ANALYSIS OF A TRICYCLE FRONT WHEEL AXLE

Due to the rampant failure of the tricycle front wheel axle in Nigeria, the failure analysis of a tricycle front wheel axle was conducted in this work. The failed front wheel axle of the tricycle part was obtained. Chemical composition, microhardness and microstructures through metallography and SEM were performed. The results show the carbon content of the failed axle wheel (0.354 wt% C) is below standard. The hardness results showed that the failed material probably had not undergone proper hardenability heat treatment to produce a hardened surface and a toughened core as the microhardness at the surface and the core were found to be in the range 254-294 HV. In addition, the metallography shows ferrite and pearlite microstructures at both the surface and the core of the failed axle. The SEM analysis of the fractured surface reveals the presence of burnished and crystalline surfaces. This shows that the failed axle does not meet the standard for the axle in terms of chemical, microstructure and hardness properties. The failure of the axle is typical of a fatigue failure.