Metallurgy examinations.(Evidence Examinations)

Comparison

Comparative examinations can determine whether two metals or metallic objects came from the same source or from each other. Metal comparisons can identify various surface and microstructural characteristics including fractured areas, accidental damage, and fabrication marks to determine whether the objects share a common origin. Moreover, the manufacturing methods used to produce an object can be determined. These manufacturing techniques can include casting, forging, hot- and cold-rolling, extrusion, drawing, swaging, milling, grinding, spinning, blanking, ironing, deep drawing, and others. Examinations can determine mechanical properties such as the response of a metal to an applied force or load. Examinations can also determine chemical composition including alloying and trace elements.

Broken or Mechanically Damaged Metal

The causes of failure or damage such as the application of stress exceeding the tensile strength or yield limit of the metal; a material or manufacturing defect; or corrosion, cracking, or excessive service usage (fatigue) can be determined. The magnitude of the force or load that caused the failure, how the force or load was transmitted to the metal, and the direction it was transmitted can also be determined.

Specification Frauds and Noncompliant Materials

Metallurgical testing of materials can determine whether inferior components were substituted in contracting frauds. The composition and mechanical properties of materials can be examined to determine if the components meet contractual obligations or appropriate regulatory codes. In some cases, the country of origin can be determined. Precious metal contents can also be determined.

Burned, Heated, or Melted Metal