Microscopic examination of a tool used in tire waste recycling

Tire recycling includes three steps: cutting strips, turning strips into small pieces, and shredding pieces into powder. The bases of the first stage machine’s cutting blades usually broke down provoking extensive down times. The paper is focused on the microscopic examination of the failed part. Historical data were collected, hardness measurements were carried out and chemical analysis was performed. The fracture surfaces and the cross section structure of the tool were in depth investigated by light and scanning electron microscopy. The fracture mechanism and the type of the fractures were discussed. The principal causes that led to the premature failure of the base are exposed. Considering the absence of similar failure analysis case studies in bibliography, the study may be useful for industries using similar cutting machinery.