Metallic Material Science



Definition

Crystal: Crystal is one dimensional(1D), two dimensional (2D) or three dimensional (3D) periodic arrangement of the atoms in a space.

Lattice: Lattice is one dimensional(1D), two dimensional (2D) or three dimensional (3D) periodic arrangement of point in a space.

Basis: The basis is the arrangement of atoms associated with each other lattice point.

Strength: It is the property of a material which resist the deformation of material in presence of external forces or load.

Toughness: It is ability of a material to absorb the energy to gets plastically deformed without fracturing.

Hardness: It is the ability of a material to resist to permanent shape change due to external stress.

Hardenability: It is the ability of a material to attain the hardness by heat treatment processing.

Brittleness: Brittleness of a material indicates that how easily it gets fractured when it is subjected to a force or load.

Malleability: Malleability is a property of solid material which indicates that how easily a material gets deformed under compressive stress.

Ductility: Ductility is a property of solid material which indicates that how to easily a material gets deformed under tensile stress.

Resilience: Resilience is the ability of material to absorb the energy when it is deformed elastically by applying stress and release the energy when stress is removed.

Plasticity: Plasticity is a mechanical property of materials that shows the ability to deform under stress without breaking, while retaining the deformed shape after the load is lifted

Polymers: A substance which has a molecular structure built up chiefly or completely from a large number of similar units bonded together,

 

What is phase? what is phase transformation?

Phase: A physically homogeneous and distinct portion of a material.

·        Gases: Gaseous state always a single phase.

·        Liquid: Liquid solution is single phase.

·        Solids: In general, due to several compositions and crystals structure many phases are possible.

Phase transformation: Phase transformation of material such as transformation between solid and liquid, for example- from ice to water. And transformation between liquid and gas, for example- from water to vapor.

 

What is Gibbs phase rule and explain it?

Gibbs phase rule states that if the equilibrium in a heterogeneous system is not affected by gravity or electrical and magnetic forces, the number of degrees of freedom is given by the equation

F= C-P+2

C= Number of chemical components.

P= Number of phases

Basically, it describes the mathematical relationship for determining the stability of phases present in the material at equilibrium conditions.

Explain unary diagrams?

According to the phase rule, three phases can exist in stable equilibrium only at a single point on a unary diagram (/ = 1 -3 + 2 = 0). This limitation is explained as point O in the hypothetical unary pressure-temperature (PT) diagram. In this diagram, the three states (or phases)—solid, liquid, and gas— are represented by the three correspondingly la-



What is cooling curves?

A cooling curve of a substance is a graph of the variation of the temperature with time as it is allowed to cool.

The gradient of the cooling curve is related to the heat capacity, the thermal conductivity of the substance, and the external temperature.