Metallography

Metallography is the study of crystal structures and phase components of metals. The properties of metals are controlled by both their microstructures and chemical compositions. For example, different microstructures could occur depending on heat treatment or solidification process for a steel specimen with the same chemical compositions. With proper cutting, polishing and etching process, the microstructure of a metal could be revealed usually with optical microscopy. By revealing material microstructures, both naturally occurring and resulting from engineering processes, metallography studies could identify metallurgical characteristics of materials such as phases, grain sizes, crystal orientations, defects and voids, phase separations, cracks and inclusions. Metallography is also one of the primary tools to analyse metal failure mechanisms including fatigue, corrosion, creep, stress ruptures, fractures, cracking and hydrogen embrittlement.

Typical Experimental Results

Optical metallograph of a malleable cast iron showing spheroidal graphite in a ferrite matrix

Optical micrograph showing dark pearlite patches distributed in the matrix of ferrite grains of a low-carbon steel surface

Applications

Alloys	Ceramics	Chemical Etching	Corrosion Analysis	Cracks
Cross-Section Analysis	Crystal Structures	Failure Analysis	Foreign Material Identification	Forensic Analysis
Fractography	Fracture Study	Grains	Grain Boundaries	Grain Growth
Grain Orientation	Grain Size	Grain Structure	IC Failure Analysis	Materials
Metals	Metallography	Metallurgy	Microscopy	Microstructure
Nano Materials	Phase Diagram	Steels	Thin Films and Coatings	Welds

For more information please read our application notes:

Mineral Identification in Geological Samples

Low-Cycle Fatigue Failure of a Steel Wire

Impact Fracture of a Metallic Hood Ornament

Instrument: Zeiss Axiotron Inspection Microscope

Key Specifications

Microscopy Type	Stereo, Compound
Optical Resolution	200nm
Magnification	0.58X-1200X
Objective	5X, 10X, 20X, 50X, 100X, 150X
Biocular Lens	5X, 10X
Imaging Mode	Bright Field, Dark Field
Sample Size	Height: 50mm; Diameter: >150 mm
Stage	Manual or automatic
Camera	Color CCD
Light Source	LED, Halogen Lamp