Introduction | Structure of Metals and Alloys | Crystalline materials
INTRODUCTION TO STRUCTURE OF METALS AND ALLOYS
Crystalline Materials:
- A crystalline material is one in which the atoms are situated in a repeating (or) periodic array over large atomic distances.
Non Crystalline Materials:
- Materials that do not crystallize are called non-crystalline (or) Amorphous materials
Space Lattice:
- Lattice is the regular geometrical arrangement of points in crystal space.
- The atoms arrange themselves in distinct pattern in space is called a Space Lattice.
- Atoms in crystalline materials are arranged in a regular 3 – Dimensional repeating pattern known as Lattice Structure.
- They are divided by network of lines in to equal volumes, the points of intersection are known as Lattice Points.
Unit Cell:
- It is the smallest portion of the lattice which repeated in all directions.
- 3D visualization of 14 Space Lattices are known as Bravai’s Space Lattice.
- If a unit cell contains lattice points only at it’s corners, then it is called Primitive Unit Cell (or) Simple Unit Cell.
- Three edge length x,y, & z and three interaxial angles α, β, & γ are termed as Lattice Parameters.
Crystal System:
- It is a scheme by which crystal structures are classified according to unit cell geometry.
Types of Crystal Systems:
- Cubic
- Tetragonal
- Hexagonal
- Orthorhombic
- Rhombohedral
- Monoclinic
- Triclinic
Crystal Systems
Simple Crystal Structure:
Body Centered Cubic Structure (BCC)
- Unit cell contains 2 atoms
- Lattice Constant a= 4r / √3, where r is atomic radius
- Atomic packing factor APF = 0.68
- Metals are Vanadium, Molybdenum, Titanium, Tungsten
Face Centered Cubic (FCC)
- Unit cell contains 4 atoms
- Lattice Constant a= 4r / √2, where r is atomic radius
- Atomic packing factor APF = 0.72
- FCC structures can be plastic deformed at severe rates
- Metals are Copper, Aluminum, Phosphorous, Nickel, Cobalt etc
Hexagonal Closed Packed Structure (HCP)
- Unit cell contains 3 atoms
- Axial ratio c/a, where ‘c’ is Distance between base planes, ‘a’ is Width of Hexagon
- Axial Ratio varies from 1.58 for Beryllium to 1.88 for Cadmium (Therefore a=2.9787, c=5.617)
- Atomic packing factor APF = 0.74
- Metals are Zinc, Cadmium, Beryllium, Magnesium etc
Crystallographic Planes and Directions
The Layers of atoms in the planes along which atoms are arranged is known as “Atomic” (or) “Crystallographic planes”.
Miller Indices:
Miller Indices is a system of notation that denotes the orientation of the faces of a crystal and the planes and directions of atoms within that crystal.
Miller Indices for Planes:
1. The (110) surface
Intercepts : a , a , ∞
Fractional intercepts : 1 , 1 , ∞
Miller Indices : (110)
2. The (111) surface
Intercepts : a , a , a
Fractional intercepts : 1 , 1 , 1
Miller Indices : (111)
The (100), (110) and (111) surfaces considered above are the so-called low index surfaces of a cubic crystal system.
3. The (210) surface
Fractional intercepts : ½ , 1 , ∞
Miller Indices : (210)
[jetpack_subscription_form show_only_email_and_button=”true” custom_background_button_color=”#ff6900″ custom_text_button_color=”#0693e3″ submit_button_text=”Subscribe” submit_button_classes=”wp-block-button__link has-text-color has-vivid-cyan-blue-color has-background has-luminous-vivid-orange-background-button-color” show_subscribers_total=”false” ]
- Dyson Electric Car | Solid-State Lithium Ion Battery | Dyson Digital Hyperdymium motorThe key developments of Dyson Electric cars are their batteries and its digital Hyperdymium brushless motors. Such techs are described in depth in the following articles.
- Dyson Sakti3 | Dyson Solid State Battery | Dyson Electric Car BatteryDyson Sakti3 Solid State Li-ion Battery | The code nicknamed “N526” had a reported driving range of approximately 965 km on a single charge utilizing Dysons patented solid-state battery technology.
- Solid State Battery | Solid State Electrolyte | Thin Film BatteriesSolid state battery You should definitely have a lithium-ion battery in your phone or camera that is compact, charges faster and rechargeable. These are solid lithium electrodes mounted in a liquid electrolyte. Solid state batteries dampen liquid electrolyte, with a rigid conducting substance, for example polymer or ceramics. These batteries would charge faster and last
- Dyson Car Patent | Dyson EV PatentDyson Car Patent “All done, see you! Internal combustion engines, cherish electric vehicles” – This is the mantra of automobile makers, all of whom commit to switch towards emission-free vehicles, whereas the policymakers have tossed forth several proposals in the span of three decades to ban gasoline and diesel engines. Thank goodness, Dyson electric car
- Transportation and Climate Change | Carbon Emissions by Transport TypeTransportation and Climate Change Road transport produces about one fifth of the world’s CO2, the main greenhouse gas (GHG) emissions an automobile and carbon dioxide emissions by Transport, Type. Even though the emissions decreased by 3.3% in 2012, they are 20.5% higher than the 1990 emissions. Transport is the world’s main sector in which emissions
