Procedures and Equipment Used in Fractography

From the preceding description of how fracture surface features are formed, it should be apparent that the presence and orientation of those features on a fracture surface can be used to infer crack direction, crack velocity, and other details of the fracture event at the moment the features were created. With that kind of information available, one can deduce a complete history of the failure process, including magnitude and direction of local stresses. In fact, the wealth of information available on the fracture surface makes fractographic examination a very powerful tool in determining how failure occurred. 

the problem in optical examination of polycrystalline ceramics such as alumina is that light reflected from interior grain surfaces can interfere with observation of fracture surface features. One can suppress these internal reflections by coating the fracture surface with carbon or other opaque material. Alternatively, the surface can be replicated and analysis conducted on the replica. Replicas using a 

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