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1. Material science and
Engineering
•A presentation on BCC
Latice.
Group Members-
1. Shreyas Dixit- 2102054
2. Somyajit Ray-
2102058
3.Souvik Mondal-2102061

2. CRYSTAL STRUCTURE :BCC
THE BCC CRYSTAL STRUCTURE
 A cubic unit cell with atoms located at all 8 corners and a single
atom at the cube center is called the body centered cubic(BCC)
crystal structure.
Each corner atom represents one eighth of an atom.Therefore
the BCC structure is said to have a coordination number of 8.
The center and corner atoms touch one another along cube
diagonals.
NAME-SOMYAJIT RAY
ROLL NO.-2102058

3. CRYSTAL STRUCTURE :BCC
UNIT CELL OF BCC
The center of the unit cell consists of one full
atom,therefore the total number of atoms in the BCC unit
cell structure is 2.
1atom+(1/8atoms*8corners) = 2atoms
The atoms in the BCC unit cell arrangement are not
packed as closely as other arrangements(such as-FCC).
NAME-SOMYAJIT RAY
ROLL NO.-2102058

4. ATOMIC PACKING FACTOR
TheAtomicPackingFactor(APF) isessentially the
densityofthe unitcell.Since weusethehardsphere
model, eachpointinsidethecelliseither partofan
atom,orpartofthevoid.
• The total volume of the unit cell is just the volume of a cube. The cube side length is a, the volume is a^3.
• Now we need to count how many atoms are in each unit cell. It may look like there are 9 atoms because there are 8 corners and 1 in the center, but
actually the cell only intersects portions of those corner atoms.
NAME-SHREYAS DIXIT
ROLL NO.-2102054

5. INTERSTITIAL SITES IN BODY-CENTERED CUBIC CELL
Interstitial sites arethespacesinsideacrystalwhereanotherkindofatomcouldfit. You
canreadallaboutinterstitial sites inthisarticle, butBCC hastwotypes of interstitial
sites: octahedralandtetrahedral
 BCC has6octahedralsites, whichmeansthatasmallinterstitial atomcouldfit in6
positions suchthatitisequallysurrounded by6FCC lattice atoms.
 These octahedral interstitial atomscanber=0.155Rsize.
 BCC alsohas12tetrahedral sites, whichmeansthatasmallinterstitial atomcouldfitin12
positions suchthatitisequallysurrounded by4FCC latticeatoms.
 These tetrahedral atomscanber=0.291 Rsize.
NAME-SHREYASH DIXIT
ROLL NO.-2102054

6. Slip system in BCC crystal structure
• Slip systems are the way that atoms
slide past each other when
deforming. Slip systems determine
many mechanical properties of
materials, and is the main reason why
a material will be ductile or brittle
• BCC crystals have 48 slip systems
but only 5 are useful. That too not all
of them are activate at all
temperatures.{110}, {112}, and {123}
are the three family of slip planes.
NAME-SOUVIK MONDAL
ROLL NO.-2102061

7. Examples of material with BCC crystal structure.
• Metals= Tungsten,Chromium.
• Ionic compunds= cesium cloride.
• The BCC crystal structure in steel.
1. α- ferite- it is the solid solution of carbon in BCC Fe.
This phase is stable at room temperature.It exists upto
912°C.
2. δ-ferrite-This phase has a similar structure as that of α-
ferrite but exists from 1395°C. NAME-SOUVIK MONDAL
ROLL NO.-2102061