List general characteristicsproperties of polycrystalline na

Solution

Characteristics/properties of polycrystalline solids:

1. These solids consist of several crystals or grains.

2. The boundary between the grain is the grain boundary across which the orientation of the crystal changes.

3. The point at which three boundaries meet is called the triple junction.

Characteristics/properties of single crystal solids:

1. It consists of only one grain or crystal, hence no grain boundaries.

2. These solids are useful for applications where grain boundaries are harmful. For example, high temperature deformation or creep resistance

Characteristics/properties of Nanocrystaline solids:

1. Nanocrystalline materials are single phase or multiphase polycrystals, where the crystal size is of the
order of a few nanometres (typically 1-100) in at least one dimension.

2. A nanocrystalline metal contains typically a high number of interfaces with random orientation relationships, and consequently, a substantial fraction of atoms lie in the interfaces.

Characteristics/properties of Amorphous solids:

1. These solids produce fragments with irregular, often curved surfaces when cleaved or broken.

2. They have poorly defined patterns when exposed to x-rays because their components are not arranged in a regular array.

3. Almost any substance can solidify in amorphous form if the liquid phase is cooled rapidly enough.