material science lec 13-19

what are mechanical properties?

describes how a material behaves under applied forces (strength, hardness, ductility, elasticity, brittleness etc…)

what are physical properties?

describes the natural characteristics of a material without changing its chemical composition (density, melting, thermal expansion)

what are optical properties?

describes how a material interacts with light (reflection, trancparency and obsorption)

what are chemical properties?

describes how a material reacts with its enviornment or other substances (corrosion resistant, chemical stability, reactivity)

what are manufacturing properties?

describes how easy a material is to process and manufacture the material (machinability, weldability catability etc…)

what are electrical properties?

describes the ability of a material to conduct or resist electricity (conductiviy, resistivity)

what are thermal properties?

describes how a material reposnds to heat (heat resistance, thermal conductivity and stability)

what are magnetic properties?

describes how a material reacts to a magnetic feild (magnetization)

what is strength?

the ability of a material to withstand applied forces without failure

what is ductility?

the ability of a material to stretch and deform before breaking

what is hardness?

the resistance of a material to scratching or indentation

what is toughness?

the ability of a material to absorb energy and resist fracture

what is elasticity?

the ability of a material to return to its original shape after deformation

what is placticity?

the ability of a material to permenantly deform without breaking

what is brittlness?

the tendency of a material to break suddenly wihtought deformation

what is fatigue resistance?

the ability of a material to withstand repeated load cycles

what is creep resistance?

the ability of a material to resist slow deformation under lond-term load at high-temperature

explain elastic deformation

1. initial:

atoms are naturally arranged, no forces acting on them

2. small load:

adding a force makes the material expand the bonds between atoms stretch but dont break

3. unload:

atoms return to their original positions

what is non-linear elacticity?

the relationship is not linear but also isnt linear

what is linear elasticity?

as force increases the deformation increases proportionally.