Metallurgy is the “study of metals.” Metallurgical analysis combined with mechanical analysis allows failure modes to be identified. There are numerous components to this discipline that include: strengthening mechanisms (heat treating, cold working, alloying, quenching, etc.); mechanical testing (tensile, compressive, shear, impact, fatigue, rolling contact fatigue, hardness, microhardness, etc.); environmental (corrosion, dezincification, wear); alloy selection (steel, aluminum, copper, nickel, etc.); physical properties (Young’s Modulus, shear modulus, melting temperature, density, etc.).
Performance, processing, alloy selection, and structure are interrelated – change one aspect and everything else can change, e.g., heat treating (process change) can result in annealing which softens the metal and produces equiaxed grains (structural change).
Material characterization includes: chemical analysis, mechanical testing, and metallography. The latter is achieved by polishing to a mirror finish and then etching in acid to reveal the microstructure, which then provides clues regarding processing history.