Let us
understand the chemical specifications of materials for vehicle armour in this
post; we will come to know the complete concept behind the selection of
material for vehicle armour after reading this post.
Chemical composition for armour material for different grades
We may see
the following chemical compositions are strictly followed during the
manufacturing of armour material because the typical properties of armour
materials depend on the following listed chemical compositions.
Compositions
are given in percentage
Grades
|
C
|
Si
|
Mn
|
P
|
S
|
Cr
|
Ni
|
Mo
|
B
|
380
|
0.13
|
0.40
|
1.40
|
0.020
|
0.010
|
1.50
|
0.40
|
0.40
|
0.005
|
400
|
0.20
|
0.70
|
1.70
|
0.030
|
0.015
|
1.50
|
0.40
|
0.50
|
0.004
|
450
|
0.26
|
0.60
|
1.50
|
0.030
|
0.015
|
1.50
|
0.70
|
0.50
|
0.005
|
500
|
0.30
|
0.70
|
1.70
|
0.030
|
0.015
|
1.50
|
0.80
|
0.50
|
0.004
|
500T
|
0.30
|
0.70
|
1.70
|
0.030
|
0.015
|
1.50
|
0.80
|
0.50
|
0.004
|
Microstructure
of used material in armour
As we have
observed that key properties of materials for armour is hardness.
Hardness
depends on the microstructure; martensitic microstructure steel will have much
hardness as compared to ferrite microstructure steel.Â
Heat treatment process plays a very important role in deciding the final product hardness.
Tempered
martensitic microstructure will have less hardness as compared to quenched
martensitic micro-structure.
Figure
shows the microstructure of material grade 380 that we have used in above column.
Surface engineering
Surface
engineering means to increase the properties by applying coating or Surface
treatment & finishing. Rate of wear of material directly proportional to
applied load and inversely proportional to hardness.
There are
following way to increase the hardness as we may see in following table
Surface
engineering process
|
Improved
properties
|
Hardness
& wear resistance
|
Anodisation , Electroplating &
TiN deposition via PVD
|
Hardness
& wear resistance
|
Ceramic coating by CVD & PVD,
nitriding, plasma spraying & carburizing
|
Wear
resistance + corrosion resistance +oxidation resistance
|
Metal spraying ,pack cementation
|
Corrosion
resistance
|
Galvanizing & electroplating
& painting
|
Wear
resistance
|
Plasma nitriding, High pressure
carburizing, ion implementation, diffusion bonding
|
Modern armour material –Aramide fiber
There are
following properties of aramide fiber that shows good indication to use as
material for armour vehicle
Tensile
strength –3620 M Pa
Density –
Lower  1.44 gm/cm3
Stiffness-
good 131 G Pa
Toughness
– excellent
But there
is some disadvantage of this material
These
materials are difficult to cut, so there will be problem in installation
Let us
move towards next post............
Keep
Reading.
No comments:
Post a Comment