Micro and Macro Structure of Solid Materials

Micro Structure of Solid Materials:

The appearance of the structure of a material under a microscope is called microstructure. Optical microscopes are used for magnifications upto 1000 times while electron microscopes can produce magnifications upto several thousand times. Microstructure of a material consists of phase structure and grain structure.

The phase structure is expressed in terms of various phases present, their relative amounts, distribution and alignment. Depending upon the number of phases present, microstructures are either single phase or multiphase structures. The grain structure of materials shows shape and size of the grains (crystals) which form the bulk material. It is characterised by grain boundaries, grain shape and size.

Macro Structure of Solid Materials:

The appearance of the structure of a material with the naked eye or by using a small hand magnifying lens is called macrostructure. Macro structural examination of a material is done to reveal the structural defects or in homogeneities of a large area. The method requires polishing and chemical etching of the surfaces to be examined.