Tractor Seat Failure
Metallurgical failure analysis was requested on a failed seat from a piece of heavy industrial equipment. Examination revealed that some of the bolts attaching the seat to the tractor had failed. Further investigation proved that not all attachment bolts had been in place when the seat had failed. The bolts that were in place were not adequately tightened. The cause of the failure was found to be inadequate maintenance on the part of the tractor owner or operator.
Tree Mulcher Failure
Metallurgical failure analysis was requested in the failure of a large piece of industrial equipment. During routine use, a wear plate separated from its support.The wear plate then became entrapped in the equipment. Visual examination showed that the cause of the plate falling off was the failure of several retaining bolts. These fasteners were found to have failed from overload stresses. One fastener head was sheared off at the chamfer seat. Visual and metallurgical examination revealed evidence that not all fasteners necessary to hold the plate in place were present at the time of the accident.
The cause of the failure was determined to be inadequate maintenance performed by the owner/operator in not insuring all fasteners were in place and tightened before operating the equipment.
Photograph A Large tree mulcher involved in the subject failure.
Photograph B Wear plate jammed between
hammer mill and debris gate.
Grass Mower Blade
Metallurgical failure analysis was requested after a large grass mower blade failure. Macro and microscopic examination along with metallurgical analysis of the failed blade revealed that cracks introduced during the heat treating process were to blame for the failure. The cracks during heat treatment were due to poor quality control on the part of the mower blade manufacturer.
Photograph A Cracks from microscopic examination of mower blade.
Photograph B Cracks from microscopic examination of mower blade.
