Q 1 On the Mechanical Behavior Testing and Manufacturing Pro

Q 1. On the Mechanical Behavior, Testing, and Manufacturing Properties of Materials;

A. What are the main factors of the material’s mechanical properties?

B. What are the available tests to study mechanical properties of a certain alloy or materials?

C. When do these tests become important?

Solution

A. Main factors of the material\'s mechanical properties or factors affecting material\'s properties:

To understand how these factors effect material properties first we need to know what are these properties:

1. Elasticity: Every material deforms on application of external load, but if a material regains its original shape on removal of external load, then that property is called as elasticity.

2. Plasticity: If a material dosen\'t regain its original shape on removal of load then that property is called as plasticity, premanent deformation takes place.

3. Ductility: Ability of a material to be drawn into THIN WIRES, that is withstand tensile loads, in other words those which can undergo plastic deformation considerably before fracture takes place.

4. Malleability: Ability of material to be drawn into THIN SHEETS that is undergo plastic deformation under compressive loads.

5. Brittleness: This is opposite of Ductility, here material do not undergo plastic deformation. It breaks on application of external load after some limit.

6. Strength: Ability to withstand mechanical load or that can resist maximum stress.

7. Stiffness: Ability of material that can resist deformation or deflection under load/stress.

Now the most important factor that effect these properties is temperature during the time of its heat treatment.

During these heat treatment processes metal is subjected to heating and cooling. The temperature to which it is heated be it critical temperature or recrystallization temperature and to how much time the metal is held that temperature, also the way it is cooled is it left in the furnace or left in still air or quenced (rapid cooling by immersing the hot metal in liquid bath), if quenched in what solution oil or water or salt solution, these factors will determine what properties the metal would take.

If one go deep in metal\'s crystal structure its lattice, its lattice defects, we can get to know who these change in properties are formed.

for example, the point defect interstitial inclusion increases strength, interstitial inclusion is the one where foreign atom will occupy space available within lattice, without disturbing the position of lattice atoms. it will increase the number of bonds with surrounding atoms hence it increases its strength.

B. Available Tests to study these properties:

C. These tests become important when one has to know the properties for an unknown material. If one is designing a bridge made up of some reinforced concrete where reinforcement is done with some metal, in this case the designer has to know till how much load the metals will not break. if he knows this value then he can make appropriate changes and make sure that load on the bridge never crosses this value. these test become important if one is in design department and constantly dealing with new metals and alloys.