Metallography Testing Services

Metallography is the microscopic study of the structure of metals and alloys. The primary objective of metallographic examinations is to reveal the ‘microstructure’ of the metals and alloys, i.e. their internal structures as a result of the composing atomic elements and their three-dimensional arrangement over distances ranging from 1µm to 1 mm by means of a light optical or scanning electron microscope. Features of interest in the metallographic study of microstructure include grain size, grain boundaries, phases, phase transformation and volume fractions, non-metallic inclusions in steel, morphology and banding, effective case depth, porosity, cross contamination etc. Microstructures of metals and alloys significantly govern their basic mechanical properties like strength, toughness, ductility, corrosion resistance and mechanical workability, and have a profound influence on their successful applications.

◘ The fundamental processes by which the object was manufactured, like casting, moulding, soldering, welding etc.

◘ The temperatures to which the metal may have been subjected during or after manufacture (including casting and annealing temperatures; tempering and quenching ranges).

◘ The presence and nature of surface coatings.

◘ An idea of the composition of an alloy, e.g. the % of carbon present in steel, or the % of tin present in a bronze.

◘ The type and extent of internal and external corrosion.

Preparation of the specimen for metallographic testing is a very important step and ‘Modi Laboratary ’ has a dedicated workshop devoted for that job. The basic steps for proper metallographic specimen preparation include: documentation, sectioning and cutting, mounting, planar grinding, rough polishing, final polishing, etching, microscopic analysis, and hardness-testing.

Since the knowledge of micro-structures of metals and alloys aids in understanding and controlling their behavior, Metallography testing facilities offered by ‘Modi Laboratary ’ are used by many industries for quality assurance, failure analysis and also for research and development.