To fulfill our clients' requests to conduct root cause metallurgical failure investigations, BEAR has expanded assessment capabilities with the construction of a full metallurgy laboratory. We now offer in-house metallographic specimen preparation, scanning electron microscopy (SEM), atomic analysis, and hardness testing. We also offer a portable X-Ray machine for quick analysis in the field.

Our new services and equipment include:

1. Binocular microscopy (photographic and videographic).
2. 3D Scanning of components, large and small.
3. Reichert metallograph for examination of polished and etched metallographic specimens up to 1800X magnification.
4. Metallographic specimen preparation including all aspects of cutting, mounting, polishing and etching.
5. Close-up 35 mm color photography.
6. Rockwell hardness testing.
7. Scanning Electron Microscope (SEM).
8. Portable X-Ray machine for quick analysis in the field

Ms Luling Sun, our metallurgist with an MA from the University of California at Berkeley offers services and failure analysis to clients and industries ranging from petrochemical, building products, aerospace, consumer products, medical and more.

Turbine Blade Failure

BEAR engineers determine the root cause for failure, not just the failure mode. The turbine blade in the photograph at right, for example, cracked due to creep (creep is deformation of a material subjected to tensile stresses at high temperature).

We can also determine whether a set of turbine blades has experienced high temperature degradation by examining their microstructures. Changes in the microstructure of blades that have been in service can signal the onset of creep damage. By sacrificing one or two blades for examination, we can determine whether an entire set may continue in service.

Sector Shaft Failure

Fracture Surface of Sector Shaft
The photograph at left shows the fracture surface of the sector shaft from the steering mechanism on a truck that was involved in an accident while transporting a full load. The fracture surface had circumferential smearing and a slightly off-center final fracture zone.

Side View of Sector Shaft
The side view of the broken shaft, at right, showed twisting deformation from torsional forces during fracture. The fracture showed no indications of fatigue cracking, which would possibly point to a defect in the shaft as the cause for failure.

By interpreting the fracture features, we were able to determine that the failure was due to a single, torsional overload event. In other words, the shaft was subjected to a force during the accident that resulted in its failure.

Metallurgy Lab