Solidification of pure metals take place animation:-
Solidification is the transformation of materials from the liquid the solid crystalline state on cooling.During solidification, the disordered structure of the liquid transforms to the orderly arrangement characteristic of the crystal. This process of solidification does not occur instantaneously. The process is characterized by the formation of numerous small particles of the new phase (s), which increase in size until the transformation completes. The process of solidification may be broken down into two stages-nucleation and grain growth. Nucleation involves the appearance of very small particles called nuclei, these nuclei then grow in size, untill the phase transformation is complete.
All solid metals are crystalline and crystals or grains are made up of several atoms. These individual crystals or grains are aggregated to form a visible mass of solid metal. These grains are formed when liquid metal solidifies. The process of solidification starts when liquid metal cooled below the equilibrium temperature (the temperature at which given metal exist simultaneously solid and liquid phase).
Solidification starts when two or more atoms associate themselves to form very small crystal called nuclei. This may happen simultaneously at a Number of locations throughout the liquid metal. At these points a few atoms assume an orderly arrangement to give the unit cubic structure and growth takes place in three dimensional as shown in fig. As a result of this growth tree like crystals known as dendrites [arise from Greek word dendrom meaning tree ] are formed. A dendrite consists of unit cell, which are exceedingly small, first form in a straight line.
Slow rate of cooling promotes crystallization while a faster cooling rate of cooling rate may prevent crystallization.
Solidification is the transformation of materials from the liquid the solid crystalline state on cooling.During solidification, the disordered structure of the liquid transforms to the orderly arrangement characteristic of the crystal. This process of solidification does not occur instantaneously. The process is characterized by the formation of numerous small particles of the new phase (s), which increase in size until the transformation completes. The process of solidification may be broken down into two stages-nucleation and grain growth. Nucleation involves the appearance of very small particles called nuclei, these nuclei then grow in size, untill the phase transformation is complete.
 |
| solidification of metals animation |
All solid metals are crystalline and crystals or grains are made up of several atoms. These individual crystals or grains are aggregated to form a visible mass of solid metal. These grains are formed when liquid metal solidifies. The process of solidification starts when liquid metal cooled below the equilibrium temperature (the temperature at which given metal exist simultaneously solid and liquid phase).
Solidification starts when two or more atoms associate themselves to form very small crystal called nuclei. This may happen simultaneously at a Number of locations throughout the liquid metal. At these points a few atoms assume an orderly arrangement to give the unit cubic structure and growth takes place in three dimensional as shown in fig. As a result of this growth tree like crystals known as dendrites [arise from Greek word dendrom meaning tree ] are formed. A dendrite consists of unit cell, which are exceedingly small, first form in a straight line.
Slow rate of cooling promotes crystallization while a faster cooling rate of cooling rate may prevent crystallization.
0 comments:
Post a Comment