Midhani is the only company in India to process very special and unique metal, Titanium, from end-to-end. It starts from having raw titanium, known as Titanium sponge and then processing it to make various highly engineered products. This presentation explains the properties of Titanium, how it is being processed in Titanium Shop of Midhani. It also contains detailed explanation of each process step.

1. PROCESS
TECHNOLOGY OF
TITANIUM PRODUCTS
PRESENTED BY :-
AMIT SINGALWAR
Assistant Manager, Ti Shop
1

2. 2
CONTENT
INTRODUCTION
PROPERTIES OF TITANIUM
PRODUCTION OF TITANIUM ALLOYS
PRODUCT QUALITY
PRODUCTION OF TITANIUM IN MIDHANI
GRADES PRODUCED IN MIDHANI
YEAR WISE PRODUCTION DETAIL
MAJOR EQUIPMENTS IN TITANIUM SHOP

3. 3
INTRODUCTION
Invented 200 years back
Commonly used in jet engines and air frames
Recent applications
Cost justified
Wonder metal
4th most abundant metal
Mineral sources are ilmenite, locoxene, and rutile

4. 4
PROPERTIES OF TITANIUM
Property Titani
um
Magne
sium
Alumi
num
Iron cop
per
1. Atomic
number
22 12 13 26 29
2. Atomic
weight
47.9024.32 26.97 55.8
5
63.5
7
3. Density
(g/cm3)
4.5 1.7 2.7 7.9 8.9
4. Melting
point (oC)
1668 650 660 153
9
108
3
5. Thermal
conductivity
(cal.cm/s.c
m2.oC)
0.0410.38 0.49 0.15 0.92
6. Coefficient
of thermal
expansion X
10-6 (/oC)
8.4 25 23 12 17
7. Young’s
modulus
(Kgf/mm2)
10,85
0
4,570 7,050 21,0
00
11,0
00
8. Electrical 55 4.3 2.7 9.7 1.7
Physical properties of titanium as compared with other metals

5. 5
Mechanical properties and impurity level of various grades
Tensi
le
Stre
ngth
(min)
MPa
0.2%
Yield
Strengt
h (min)
MPa
Impurity limits, wt
%
N
(ma
x)
C
(ma
x)
H
(ma
x)
Fe
(m
ax)
O
(m
ax)
1. ASTM
Grade
1
240 170 0.0
3
0.1
0
0.0
15
0.2
0
0.1
8
2. ASTM
Grade
2
340 280 0.0
3
0.1
0
0.0
15
0.3
0
0.2
5
3. ASTM
Grade
3
450 380 0.0
5
0.1
0
0.0
15
.
03
0
0.3
5
4. ASTM
Grade
4
550 480 0.0
5
0.1
0
0.0
15
0.5
0
0.4
0
5. ASTM
Grade
7
340 280 0.0
3
0.1
0
0.0
15
0.0
3
0.2
5
Titanium alloys
Can be suitably alloyed with various elements
More than 30 alloys are commercially available
2 allotropic forms: alpha titanium and beta titanium
Alpha stabilizer: Al, O, Sn, Zr etc.
high strength, creep resistance, good weldability, toughness
Beta stabilizer: Mn, Fe, Cr, V, Mo, Hf, Nb etc
high formability, low creep resistance, DBTT

6. 6
S.
N
o
Alloy Type Max
U.T.S
(MPa)
Max
0.2%
Y.S.
(MPa
)
Area of
application
1. C.P.
Titani
um
Alpha 650 485 Airframes,
body implants,
chemical &
marine
2. Ti-
5Al-
2.5Sn
Alpha 790 760 Chemical,
marine
3. Ti-
8Al-
1Mo-
1V
Near
Alpha
900 830 Chemical,
marine
4. Ti-
0.2Pd
Alpha 340 280 Chemical
5. Ti-
6Al-
2Sn-
4zr-
2Mo
Near
Alpha
900 830 Jet engines,
compressor
parts,
airframe skin
6. Ti- Alpha 900 830 Pressure
Some important alloy and their application

7. 7
Flow chart for production of titanium ingot

8. 8
PRODUCTION OF TITANIUM ALLOYS
Processing of Titanium
Charge Preparation
Melting
Effect of Vacuum
Hot Topping and Cooling
Magnetic Effects

9. 9
PROCESSING OF TITANIUM
Most common practice:
blending or raw material, pressing the mixture
into blocks, welding of the blocks and bulk scrap and
melting
Ingot size range:
550-860 mm
Ingot weight:
1.4-4.5 T

10. 10
CHARGE PREPARATION
Requires clean, uniform and well characterized raw material free
from harmful inclusions
Easy to melt alloying element:
Al, Cr, Cu, Fe, Mn, Sn, Zr etc.
added in elemental form
Refractory metals:
Mo, Nb, Ta, V etc.
added as alumothermic-reduced master alloys
Oxygen can be added as TiO2 and less refractory compatible oxides
●
BLENDING OF CHARGE
●
CONSOLIDATION INTO BLOCK
●
ARRANGED IN THE JIG
●
WELDED BY CONSUMABLE ARC OR PLASMA METHOD

11. 11
MELTING
Electrode is suspended in vacuum arc furnace
Melting initiates at a low power setting
Negative polarity is given to the electrode
Operating voltage: 25-30 V
Melting current: 12-24 KAmp
Melt rate : 0.8 X crucible diameter
Arc length: 25-30 mm
SAFETY FACILITY
Automatic shutdown of equipment
Explosion ports
Barricades

12. 12
EFFECT OF VACUUM
Effects arc behaviour and product quality
Low vacuum:
●
unstable arc,
●
wander erratically
●
tendency to move to crucible wall
Operating vacuum level:
●
5-50 microns
HOT TOPPING AND COOLING
Starts when 90 % or more the electrode is consumed
To avoid formation of pipe and gas cavities
Cooling is done in vacuum
Fine deposits of Mg, Na or Ti in the furnace can be hazardous

13. 13
MAGNETIC EFFECTS
Arc is affected by
●
magnetic field produced by high arc current
●
power leads, ferrous structures
●
other electrical furnace and equipment
Adjoining furnace “talk” to each other
Common practice to employ a solenoid around water jacket
Commonly referred as “stirring” coils
Controls the arc and stir the molten pool slowly and gently
2 types of magnetic control coils
●
permanently placed around water jacket over entire length
●
shorter and movable to cover only arc zone
Magnetic field is automatically reversed at regular short intervals

14. 14
PRODUCT QUALITY
Low density and hard inclusions:
Alpha stabilized particle with large amount of N and/or O
Hard and brittle
Difficult to detect
Attributed to air contamination during sponge production
Caused by localized oxidation, burning and surface leaks, poor
shield welding, foreign material, low quality scrap
Triple melting is a solution but not 100 %
High density inclusions:
Refractory metals and refractory metal carbides
Main source is recycled scrap
High m.p.; so resist melting and sinks to bottom of molten pool

15. 15
Soft alpha segregate
Large alpha stabilized regions
Generally found in alloy containing Al and Sn
Unique to Ti-alloys and found in shrinkage pipes
Appear as light and dark etching lines in microstructures
Impair transverse mechanical properties
Can be minimized by proper hot topping
Ingot porosity
Associated with residual chloride salts in the sponge
High melt rate produce more porosity than low melt rate
Can be avoided by proper hot topping

16. 16
Ingot surface
Affects metal yield and conditioning cost
Large gas content results in much spatter and vapour deposition
High skull on first melt ingots
Primary electrodes are brushed to remove condensed salt
Poor electrode spacing, centering and improper solenoid operation
results in non-uniform surface
Arc dwelling for longer time in one direction near crucible wall

17. 17
PRODUCTION OF TITANIUM IN MIDHANI
Visual inspection
Mixing
Compact pressing
Plasma arc welding
Dehumidification
Vacuum arc remelting
Ingot turning
Division of Shop
Titanium sponge
Master alloy i.e. Al-V, Al-Mo, V-Al etc
Titanium scrap
Zirconium sponge
Various virgin metals i.e. Sn, Al, Mn, Cu etc
TiO2 powder
Raw Materials Used

18. 18
A. Commercially pure titanium
1. Titan-12 Ti 99.8%
2. Titan-15 Ti 99.7%
3. Titan-18 Ti 99.6%
4. Titan-20 Ti 99.5%
B. Ti alloys
1. Titan 14 Ti-1Ni-0.5Mo
2. Titan 21 Ti-5.3Al-2.5Sn
3. Titan 24 Ti-6Al-2Sn-4Zr-2Mo
4. Titan 26 Ti-6Al-5Zr-1Mo-0.3Si
5. Titan 29/
IMI 834
Ti-5.5Al-0.5Mo-4.0Sn-
0.7Nb-0.3Si-4Zr-0.06C
6. Titan 31 Ti-6Al-4V
7. Titan 42 Ti-3Al-15V-3Sn-3Cr
8. GTM Ti 64 Ti-6Al-4V
9. GTM 900 Ti-6.5Al-3.3Mo-1Zr-
0.3Si
10. PT-1M Ti-0.4Al
11. PT-7M Ti-2.5Al-2.5Zr
12. VT 14 Ti-6Al-1.5V-3.5Mo-
0.1Fe
13. Half Ti 64 Ti-3Al-2.5V
VARIOUS GRADES PRODUCED IN MIDHANI

19. 19
C. Russian grades
1. BT 3-1 Ti-6.5Al-2.5Mo-1.5Cr
2. BT 5-1 Ti-5.6Al-2.6Sn
3. BT 6 Ti-6Al-5V
4. BT 9 Ti-6.3Al-3.3Mo-1Zr-
0.3Si
5. OT 4-1 Ti-2.3Al-2.2Mn-0.1Fe
D. Niobium alloys
1. Niobhat 101 Nb-10Hf-1Ti
E. Developmental alloy
1. Titanium
aluminide
Ti-11.5Al-37Nb-2.7Mo-
2.1Zr-0.13Si

20. 20
Titanium
Steel Total
Pri Sec Ter Pri Sec Ter
2012-2013
Product
ion (T)
102.
2
121.
95
0 0 1451.
96
9.6
5
1685.
76
No. of
heats
27 33 0 0 247 2 309
2013-2014
Product
ion (T)
254.
36
252.
56
0 0 1000 39.
25
1546.
196
No. of
heats
74 75 0 0 173 7 329
2014-2015
Product
ion (T)
255.
19
135.
86
0 0 987.
53
0 1378.
585
No. of
heats
68 40 0 0 170 0 278
2015-2016 (Till now)
Product
ion (T)
304.
25
51.2
5
4.1 0 593.
336
0 952.
936
No. of
heats
82 20 2 0 112 0 216
Year wise production detail

21. 21
Major Equipments in Titanium
Shop
3000 T compacting press
2. Plasma Welding Unit
3. Vacuum Arc Remelting Furnace
4. Vacuum Annealing Furnace
5. Skull melting furnace

22. 22
Plasma Welding Unit
- When passed current through inert
gas, it becomes ionised to form plasma
Becomes conductor of electricity
Comes out of nozzle at high velocity
and high temp
In Midhani, plasma welding unit is used
to weld Titanium compacts

23. 23
Vacuum Arc Remelting
This is a consumable electrode remelting process performed inside a
vacuum chamber.
Exposure of molten metal droplets to vacuum reduces free gas
content in the steel providing a cleaner product with little
segregation.
Consistently higher yields and reproducible metals are assured
through fully automated computer/load cell control throughout the
remelt process eliminating the need for operator intervention.
The end product is a dense ingot with minimum segregation and very
low hydrogen and oxygen levels.

24. 24

25. 25
Vacuum Annealing Furnace
Heating to a predetermined temperature, holding at specific
temperature and cooling at very slow temperature
Purpose
Relieving internal stress
Improve ductility & strength
Enhance machinability
Refine grain size
Reduce the gase

26. TITANIUM SKULL MELTING FURNACE
(supplied by HEBA II USSR(1968), Capacity 120 Kg
Enhanced with
High capacity vacuum pumping system
Ultimate vacuum <10 microns
Centrifugal casting chamber
Original
Old vacuum pumping system: UV >40 microns

27. 27
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