|Introduction: Metallographic examination is performed on metals to
investigate the grain size, inter- or intra-granular microfractures or interface
between grains. It is done after cutting and mounting the metal in an
appropriate media. This is followed by polishing and etching to reveal the
grain boundary and other features. The polished sections are examined
using a metallographic microscope.
A metallograph of a bronze-patina interface is shown below. This cross
section was taken to examine the metal-patina interface in ancient bronze
sculpture. The objective was to investigate the authenticity of this particular
bronze object by examining the depth of penetration of patina into the metal.