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OCR for page 101
Chapter 9
END USES OF TITANIUM
"Light, strong, ductile, and corrosion-resistant" were the features
that sold titanium offered from the beginning. "Light and strong" meant
a higher strength-to-weight rat to than that possessed by aluminum and
steel up to 550°C. "Ductile" implied formability and toughness.
"Corrosion resistance" signified maintenance-free aircraft even on
seawater-drenched carriers. Thus, in the early 1950s, the newborn jet
aircraft industry and titanium seemed made for each other. Starting in
the 1960s, industrial uses of titanium began to become significant.
During the 1970s, commercial and military aerospace uses continued to
increase, although erratically; industrial applications grew steadily and
in 1980 amounted to one-fourth of total titanium shipments. A number of
large-potential industrial uses have emerged, and it appears possible
that one or more of them could grow in the next decade or two to rival
the still-growing uses of titanium in the aerospace industry.
Reason for Titanium Use
The element titanium in bulk metallic form is a relatively
low-strength plastic solid of intermediate density that is extremely
reactive chemically. However, the metal has an adherent, nonporous,
chemically-inert oxide skin that makes titanium one of the most
corrosion-resistant of the structural metals. Titanium also has low
thermal and electrical conductivity and a weak paramagnetic response.
The usefulness of titanium as an engineering material is related to its
uniquely desirable combination of chemical, physical, and mechanical
properties and to the ability to prepare high-strength, tough, and
ductile alloys from the base material.
Materials of low to moderate and high strength result f ram the
alloying of titanium with elements such as aluminum, tin, oxygen, iron,
vanadium, chromic, and molybdenum . The ductility and toughness of such
alloys are commensurate with the strength levels attained and are quite
satisfactory for most engineering purposes. Properties are maintainable
over a wide temperature range. The materials are very competitive with
other engineering materials when compared on a strength~density basi s .
Figure 12 shows comparative tensile strength density data over a range of
temperatures.
In addition to desirable combinations of mechanical properties,
titanium and its alloys are quite corrosion resistant in most common
environments and even in some that very aggressively attack most other
101
OCR for page 102
102
1~2
1.'
t.O
0.9
O 0.8
C
O 07
lo
0.6
AS
-
~ O.C'
._
C 0~3
Oi!
0~1
o
_
~~~ I , · . . .
lly~hBOl-~.O:~d
. - ` AL ti'cn;um belo sIto'
lidiesteel
_
_
~4340 {mod)_
1 ~Y\YPH ~toinlesS
1
1 1
he
. ~ -a.-~ ~e _,. .~ I._ . _
I ~c~-loo o.umlnum cloy-
0 400 800 1200
Temperoture, OF
~ 1
_
Figure 12 Comparison of tensile stength~density ratio f or
titanium alloys, three classes of steel,
and 2024-T86 aluminum alloy.
-
engineering metals. This resistance to chemical attack is maintained to
moderately high temperatures. Oxidation reactions in titanium are
insignificant in terms of consuming or embrittling the bulk material over
the pref erred range of temperatures where the useful strength of titanium
i ~ to be maintained .
titanium are
bulk
OCR for page 103
103
There are additional good reasons for using titanium. For example,
its modulus of elasticity is intermediate between that of aluminum and
steel, which permits good structural compatibility in mixed metal
structures. Further, the modulus-to-dens~ty ratio is quite high compared
t o that of some other structural materials and that permits an economy in
minimum weight designs. Figure 13 shows comparative modulus density
ratio data over a range of temperatures. The fatigue and creep strengths
of titanium alloys also are excellent (Figures 14 and IS). In addition,
the thermal stability of selected titanium alloys in preferred
heat-treated conditions is outstanding, and the the low thermal-expansion
characters attics of titanium per Wit dimensionally stable structures.
1 Ti-8Al- loo- 1V
2 PH 14-8 Mo Steel
80
60
0 100 300 500
Temperature, 'F
Figure 13 Materials stiffness efficiency after 24,000
hours temperature.
Source Fa~rbairn 196 4.
1
3 T~-6A1-4V
4 2219 Al
700 900
OCR for page 104
u)
104
120
100
~0
- 60
20
, ~ ,~ r-6Al-6v-2S~ [RsO.I]
>\~\ 7;-6~1-~
\ .'. ~ ` ~(nougat
`~~
\ · T-sA1-2.ssn
Ronge. for (moth) [R: -I
~ ~[R ~ O." to
-
rt-S&~-2.SSn 1 - tt~et, ~t ~ 4) [R: -13
80. 10' 60' 10'
Life cycle
Figure 14 Typical room temperature fatigue characteristics of
selected titanium alloys.
Source: Wood 197 S.
Titanium materials are forged to shape readily and are fabricated to
end items using common metalworking techniques. Several commonly used
grades (e.g., grades of unalloyed titanium and the Tz-5Al-2.5Sn,
Tz-6A1 - V, and Ti-3Al-2. 5V alloys) are fusion~eldable via all of the
~ nert-gas-shield~ng techniques. Most of the alloys are heat-treatable to
a rave of strength levels. Machini sag and finishing procedures have been
d eveloped into routine operations.
Although this description of titanium' s attributes is not exhaustive,
it can be clearly recognized that there are many reasons f or selecting
titanium as the material of choice for d~scr~m~nat~ng applications. The
following sections provide some insight regarding where titanium and its
alloys have f ound greatest use and where the use of this material might
be extended in the years ahead.
OCR for page 105
105
104
100
30
80
70
60
SO
~0
~0
20
Temperoture, °F
\
\ \
\
\ ~ \
~\0.2%
Ti- 661- 4V (STA)\0 2 °;O f ~
T'-641- 2Sr.- aZr - 6Mo (STAN
~ ~. .2%
Ti- 641 - 6V- 2 Sn (574:
10 ~
2S 27 29 3 1
,;~Ti;SAI- 6Sn- Ear- I Mo- 0.255i
,
\ ~
`` Rupture
' "
\ 0 2 %
\0.2 °/O ~
\ ~
\ \
Ti - 6AI - 2Sn- ~ 2r - 2Mo (STA)\
\ ~
STA = solution treated and aged
33 35
Lorson-Miller Porometcr, P: ~ (20 ~ 1o; I)
1 000
Figure 15 Typical creep and stress rupture behavior
of selected titanium alloys.
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106
Use History
The impetus for the birth of the titanium industry was provided by
military planners who believed that titanium would fill several of their
material needs. Those needs were related to the development of the gas
turbine engine for aircraft propulsion and the development of lightweight
armor and ordnance; the corrosion resistance needed of materials for the
saltwater environment also were influential. Ordnance hardware (e.g.,
mortar base plates and artillery flash suppressors) were among the
earliest titanium applications. By 1955, about 90 percent of the
titanium production was used in building aircraft and engines (Table 14~.
TABLE 14 Use Distribution of Titanium in 1955
~ _ _ _.
Percent of Total Mill Products
Use Category Source Ad Source B ~
Military aircraft gas turbine engines 47.1
Military airframes 36.2
F~ It tary nonaircraf t uses 10.4
Commercial airframes 6.1
Industrial (corrosion resistant) uses 0.2
a Goodwin 1956.
b Jaffee 1962.
60
33
4
3
Between 1955 and 1960, a dramatic 50 percent drop in titanium
production and use resulted from the shift in military planning from a
strategy involving manned aircraf t to one with reliance on unmanned
missiles. This dip is reflected in mill product shipments shown in
Figure 16. This figure shows the predominance of titanium use by the
aircraft industry over all of the early history. The detailed use data
over a 12-year period are given in Table 15.
Data by major titanium use category over the most recent decade of
titanium's history (1971-1981) are plotted in Figure 17 (the same data
are plotted separately in Figure 1~. Although these data do not present
a detailed picture, they clearly show that the aerospace industry still
consumes over about three-quarters of all the titanium mill products
shipped. The steady growth in consumption by the nonaerospace markets
for titanium is of particular interest.
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107
S per 1b
28
K
41
C
° 11
o
C
8 l.
CJ
:'
o
-
-
-
: ~_
Million lbs
\
~_
~n_ts
· a° C~
30 U~
t10 ~
-
.
-
I'tS
1~" "~, l~d I'AS I't.
Figure 16 Titanium industry market prof ile (based on 1968 data)
TABLE 15 Utilization of Titanium 1961-1973
.
Use
Wood datal
Aircraf t
Jaffee dataE
Percent
_ _
1971E 1973
Mi litary engines 37 32 20 14
Airf rames 26 25 10 20
Subrotal 63 57 30 34
Commercial engines 10 13 31 23
Airf rames 4 7 15 17
Subrotal 14 20 46 b'O
TOTAL 77 77 76 74
Other
Mi ssles and space 16 15
Helicopters and
ordnance
Industrial uses
7
1 1
16 18
~_
7
TOTAL 23 23 24 26
a Wood 1975
b Jaffee 1962.
OCR for page 108
108
~1
~1
~1
AS
a:-
o
~ 25
- 20
-
-
t~
10
~1
OF , ~
.98tE^~d l\
J a''t=~ - ce
-
-
~ Indu~rial Me^-ts
, ~. t t ~t ~ ~ I ~ t I l
7D 72 74 ?. 78 ~ at
Yeer
Figure 17 Titanium industry market pro f lie based on 1980 Data.
Source: Minkler 1980.
Overall, of the total quantity of mill products ~ 2 81, 000 tons ~
shipped in this period, over 220,000 tons (or nearly 78 percent) of total
shipments have been utilized by the aerospace industry. Industrial uses,
primarily for corrosion-resistant applications, have taken over 33,000
tons (between 11 and 12 percent), and over 22,000 tons (nearly 8 percent)
have been applied to other nonaerospace uses.
Aerospace Appl ications
Ga ~ Turbine Engine s
The Pratt & Wh! tney (P&W) J-57 gas turbine engine was one of the
first important applications for titanium. Some of the early versions of
this engine, applied to such military aircraft as the B-52 and the
KC-135, flew with only 10 pounds of titanium . A later version of the
J-57 contained 7 percent of the engine weight in titanium components
(about 260 lbs) for the low-pressure compressor stages (discs and blades
only). Advanced versions of the J-57 engine (e.g., J57-P-43W) were
constructed with more than twice that amount of titanium (15.6 percent,
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109
586 lbs) . In that engine, the inlet case and the front compressor case
were constructed of unalloyed titanium. Ti-6Al-4V alloy was uled for
front and rear compressor blades, the front compressor discs, hubs,
spacers, and some of the rear compressor discs and spacers.
Gas turbine engines for commercial aircraft began in a similar way.
The first engine models did not contain titanium (e.g., the P&W JT3A,
JT3C6, and JT3C7 for the Boeing 707 and 720, and the Douglas DC-8
contained no titanium) . Advanced versions of the JT3 engine, the JT3D-1
and -3, and later the JT4A-5 (for later models of the Boeing 707 and
Douglas DC-8) and the JT8D-1 engine (for the Boeing 727 and Douglas DC-9)
each contained several hundred lbs of titanium, principally unalloyed and
Ti-6Al-4V alloy (Table 16) e
TABLE 16 Titanium Use in Pratt & Whitney Gas Turbine Engines For Commercial
Airliners
Components
JT3D-1 JT8D-1
Ti wt. Stage Material Ti wt. Stage Material
~ lb)
Inle t case 91 - cpa 64 - cpa
Compressor (alloyb)
Vanes 72 1 alloyb 45 1 alloyb
Discs and hubs 174 1-9 alloy 96 1,2,4-6 alloy
Spacers and seals 23 1,2,4 alloy 21 1,2,4-6 alloy
Blades 205 1-9 alloy 125 1-9,12 alloy
To tal 565C 351i
a Commercially pure unalloyed titanium.
b Principally Ti-6Al-4V alloy.
c Equals 13.8 percent of the total engine weight of 4, 090
d Equals 11.6 percent of total engine weight of 3,024 Ibs.
The General Electric ~ GE ~ Company, who also pioneered in the
development of aircraf t gas turbine engines and the use of titanium to
reduce engine weight, introduced a modest amount of titanium in its J-79
engine and increasing amounts in engines of later design. This
increasing use of titanium in GE engines f ram the mid-1950s to the
mid-1960s is shown in Table 17. A large proportion of engine weight in
the TF39, a high-bypass turbofan engine, was of titanium.
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110
TABLE 17 Evolution of Materials Use in General Electric Gas Turbine Engines
Percent of Material Usage
.
Engine Year Aircraf t Composites Al/Mg Titanium Steels Superalloys
J47 19 45
J79 1955
J93 1960
GE4 19 65
TF39 1965
Ne xt g enera t ion
F-86, B-47 0
F-104, B-58,
F-4
XB-70
SST
C5A
o
o
2
5-10
Source: Simmons and Wagner 1970
22
3
0 70 8
2 85 10
1 7 24 68
1 12 15 72
1 32 18 4 7
1 25 15 50
The engines for commercial aircraft, the GE CF6 core engines, and the
P&W JT9D engine series also are of the front-fan, high-bypass-ratio type
and contain large quantities of titanium. Simmons and Wagner (1970)
discuss the development of the front-fan engine in terms of titanium
utilizat ion as f allows:
The large high-bypass turbofan engines could not have been developed
without strong lightweight titanium alloys. The percentage of
titanium alloy in the TF39 engine for the C5A has reached 32 percent
of the total metals weight in the engine. This may be the high point
for titanium usage in jet engines, because two factors will work to
reduce the application of titanium. The f irst is the use of
composites, which is just beginning. Large fan part s that now
account for most of the titanium alloy usage can probably be made
largely of composites. The second factor is the increased
temperature in the compressors of supersonic engines, which has
a [ready necessitated the replacement of several t itanium s sages in
the hot end by parts made of a nickel-base alloy. However, new
manufacturing techniques may result in lighter hollow titanium fan
and compressor blades that could make it quite difficult for
composites to replace them. Ti-6Al-4V alloy has been the high-volume
alloy in gas-turbine engine applications, with some Ti-8Al-lMo-lV and
Ti-5A1-2 . 5Sn alloys being used . It i s expected that
'ri-6Al-2Sn-4Zr-2Mo and Ti-6Al-6V-2Sn alloys will reach high-volume
usage in advanced engines. Tables 18 and 19 list titanium use in a
typical modern fan-jet engine by component and alloy.
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111
TABLE 18 Titanium Use by Component in a Typical Modern Fan-Jet Engine
~_~
Part Material
.
Alternate Ti Alloy a Alternate Material a
Inlet case 5Al-2.5Sn Tib, 8Al-lMo-lV 12Cr "stainless" steel
Fan blades 8Al-lMo-lV 6A1-4V, 6Al-6V-2Sn CompositesC
Fan disks 8Al-lMo-lV 6A1-4V, 6Al-6V-2Sn, Low-alloy steel' 12Cr
Ti 67 9 steel
Fan exi t
struts 6A1-4V Tit, SA1-2. 5Sn 12Cr steel
Fan duct Ti, 5A1-2. 5Sn 8Al-lMo-lV A1 alloy
Fan duc t
f airings Tib 5A1-2. 5Sn A1 alloy
Front camp.
blades 8Al-lMo-lV 6A1-4V, 6Al-6V-2Sn 12Cr s teel
Front camp.
disks 8Al-lMo-lV 6A1-4V, 6Al-6V-2Sn Low~alloy steel, 12Cr
steel
case
Rear camp.
blades
c
Front camp.
case 6A1-4V 5A1-2 . SSn, 8Al-lMo-lV 12 Cr s teel
Interned .
5A1-2. 5Sn
8Al-lMo-lV
8Al-lMo-lV
12Cr steel
6A1-4V, 6Al-2Mo-4Zr-2Sn, 12Cr steel, Ni alloy
Ti 67 9
Depending on temperature, stress, corrosive resistance, cost, and
we ight requirement s .
b Commercially pure titanium A-55 or A-70 grade.
Such as graphite f iber-reinforced epoxy and boron-reinforced
aluminum.
Source: Simmons and Wagner 1970.
Small gas turbine engines also used titanium. The weight incorporated
into the designs of these smaller engines was not remarkable . However, in
several instances, production runs for the smaller engines were substantial
and accounted f or an appreciable consumption of titanium . Engines produced by
such companies as AiResearch (e.g., models TPE-331, T-76, and TFE-731) and
Lycoming (eege, model T53-L-13) were important for their use of titanium.
A list of representative gas turbine engines that collectively utilized
large quantities of titanium is given in Table 20. Where the information is
available, the approximate purchase weights of the titanium required to make
the parts that ultimately fly in the engine are given as are representative
airframe model numbers that utilized the engine models listed. Note that the
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t
114
TABLE 21 . Estimated Purchase and Fly Weights of Titanium in Airframes
of Commercial Airliners
Aircraf t System ~Fly Weight
(lb) (lb)
Boeing
707500 190
7271,800 750
7373,200 1,100
74732,000 11,000
747SP45,000 12,000
7 57a3 5, 000 9, 500b
Mc Donnel 1-I)oug la s
DC-9-302,000 600
DC-~-6210,000 2,426
DC-10-3030, 000 8, 100
Lockheed
L-101131, 600 14, oooC
a
b
c
The weight of the 757 is approximately one-quarter of the f ully
loaded weight of the 747.
No t f inal as of early 1981.
Includes titanium in engines for fly weight (about 6000 lbs), but not
for purchase weight. .
TABLE 22 Alloys and Fly Weights of Titanium in the L-1011 Alrframe
Component s Alloy Fly weight
~(lb)
Forgings Ti-6Al-4V, Ti-6Al-6V-2Sn1, 300
Extrusions, sheet, springs Ti-6A1-4V, Ti-13V-llCr-3A13, 600
Fasteners Ti-6Al-4V2, 000
Failsaf e straps Ti-6Al-4V, Ti-6Al-6V-2Sn500
Other systems Ti-6Al-4V, unalloyed Ti1, 200
Source: Data from industry spokesmen.
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115
TABLE 23 Mill Product Forms for the F-14 and F-15 (purchase weighta)
F-1-4
Form Estimated amount
(lb)
Forgings22,400 Forgings 29,150
Plate12,000 Plate 11,000
Sheet4, 400 Sheet 5, 200
Bar and tubing1, 200 Extrusions, tubing,
and f asteners 11, 350
To tal40, 000 Total 56, 700
Estimated fly Estimated fly
weight5,190 weight 6,940
Percent of
purchase weight13
Percent of
purchase weight 12.1
a Purchase weights are approximate.
Source: Wood 1975, Wood and Barr 1974, and data from industry spokesman.
The estimated titanium purchase weights for airframe construction for
some other military aircraft are listed in Table 24. The fly weights are
not as readily available as the purchase weights but, where given,
indicate a low utilization ratio. Industry spokesmen have commented on
the low utilization ratio in the past as is indicated in the following
excerp t f rom Wood ( 1975 ):
The large amounts of thick-section mill products used in
sophisticated aircraf t such as the F-14 and F-15 lead to low
utilization ratios. For example, only about 12 percent of the
56,700 lbs of the titanium purchased flies in the F-15 airframe.
Using forgings as an example, forgings of 1,275 and 900 lbs are
machined down to 14 5 and 100 lbs f inished part weights,
respectively, representing only about 11 percent utilization.
Forgings are generally not amenable to a high utilization ratio,
since blocker type forgings are usually purchased and because the
parts vary in section thickness from point to point. Precision
forgings might be ordered for some shapes in the smaller sizes,
but they are more expensive than blocker shapes and not available
in large sizes.
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116
TABLE 24 Estimated Purchase and Fly Weights of Titanium in Military
Airf rames
Aircraf t
System
Purchase Weight Fly Weight
(lb) (lb)
A-411
A-6E
A-7E
F-4JtM
F-5E/F
A-1OA
F-16
F-18
C-130H
B-1
150
600
280
2,800
750
2,600
3,000
6,000
1,000
170,000
50
185
1,200
24, 800
Source: Wood and Barr 1974, and data from industry spokesmen.
The possible application of the advanced metallurgical processes for
producing near net shapes (eege, isothermal forging, isothermal shape
rolling, superplastic forming, superplastic forming with diffusion
bonding, and powder metallurgy and metal casting techniques) is believed
to offer the means for greatly improving the utilization ratio of
titanium in constructing airframes. Wider adaptation of these methods to
a large variety of airframe parts could result, as noted in Chapter 11,
in a considerable material saving. For an aircraft weapons system such
as the B-1, a large vehicle with about 18 percent of its airframe weight
in titanium, the raw material savings could be remarkable.
Missiles and Space Vehicles
Titanium was considered quite early for missiles and other space
vehicles. For example, titanium was designed into the Navaho air
breathing missile (principally Ti-13Y-llCr-3A1 alloy) and, although this
missile never became a production item, the application generated an
interest in titanium for use in other systems. Af ter the low production
year of 1958, almost 1 million lbs of titanium were incorporated into
missiles and space probes in 1959. Almost 2 million lbs of titanium were
applied to space vehicles in 1960, a remarkable growth.
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117
There are six major applications for titanium in missiles and space
vehicles. These are listed in an early 1961 Titanium Metals Corporation
(TIMET) brochure as:
1. Cryogenic pressure vessels for liquid-fueled missiles.
2. Storage tanks for cryogenic fuels and structural components of
space vehicles designed to operate in the cryogenic temperatures
of space.
3. Rocket motor cases f or solid-fueled vehicles.
4. Nozzle exit cones.
5 . Co ntro 1 mechanisms such as servo valves, gyro scopes, gimbal
housings, and tubes for communications devices.
6. Miscellaneous components such as interstate structures, adapter
rings, and skins.
Titanium pressure bottles (Ti-6Al-4V) were outstandingly successful
in the Atlas launch vehicle (about 7S lbs finished weight per bottle), in
the Agena A satellite, and in the Ablestar spacecraft with a
restartable engine. Project Mercury, the first manned spacecraft,
utilized titanium panels for the inner shell of the vehicle. This
vehicle also used a 205-lb ring in an adapter section of the system.
Pressure bottles of titanium were used in the follo~up Apollo program
and the associated moon-lander vehicle. In later programs, titanium was
selected for the frame of the space telescope. The Space Shuttle
vehicle, although not primarily of titanium design, requires 25,000 lbs
of titanium raw materials (purchase weight) for each craft.
The use of titanium in the transtage section of the Titan II military
strategic missile was an important application (components machined from
large forgings). The Minuteman II and III missiles' second-stage motor
cases were made of Ti-6Al-4V and their production was continued into the
1970s (Model III and a shroud that was retrofitted to Model II
vehicles). The purchase weight of titanium for each of the Minuteman III
missiles was greater than 7,000 lbs. In addition, titanium was designed
into the Po seidon, the Polaris, and into tactical missiles as well. Only
small amounts of titanium are used in components for the last group
(e.g., in pressure bottles and in turbine wheels) , but in several cases,
such missiles were produced in large numbers (e.g., Hawk, Dragon, Lance,
TOW, Sparrow, Sidewinder, Phoenix, Maverick, and Harpoon.
Non-Aerospace Applications
Ordnance
The promise and hopes for titanium in ordnance applications were never
fulfilled to the degree that was anticipated during the formative years
of the industry. There were some limited successful early applications.
A mortar base plate and an artillery flash suppressor are examples;
however, basically, many of the attempted applications for titanium never
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118
matured beyond the developmental stage (e.g., the use of titanium alloy
as components of battletank treads and in the suspension system can be
cited). Entryport tank hatches also have been made of titanium for ease
in operation by one man. In the 1970s, titanium alloy again was examined
f or use in the suspension system (torsion bars) of military ground
vehicles (Scout, an armored personnel carrier) only to be eliminated in
the final material selection process.
If helicopters are considered as being within the ordnance category,
then titanium can be thought of as winning an important place in ordnance
as a preferred material in the construction of its component parts. Some
helicopter models require thousands of pounds of purchased titanium;
however, titanium use in helicopters generally is included under the
aerospace category. It is used principally in engines but also in some
parts of the airframe systems. Rotor hubs and blade components are
notable examples. Alloyed titanium also has found use as armor plate in
helicopters (e.g., more than 1,200 lbs of titanium has been used around
crew stations, fuel tanks, and the propulsion system on a single HH53B
helicopter).
Use of titanium as armor in other instances can be cited. For
example, during the Vietnam War, plates of Ti-6Al-4V alloy were loosely
attached to the truck-body sides of personnel carriers for protection
against small-arms f ire . A bathtub-like enclosure of Ti-6Al-4V plate
around the rear and sides of the pilot ' s seat in the A-1OA aircraf t, and
in other combat vehicles, represents a present use in the armor
category. As another example of the armor application, the Ti-5Al-2.5Sn
alloy is used in the "Standard Type A, Hl" body armor vest (6e 5 lbs per
vest). Civilian versions of body armor (vests) also use titanium. At
one time, titanium was considered for ground troop combat helmets
(Ti-5Al-2 . 5Sn) . Implementation of this plan, which required slightly
under 2 lbs of titanium per helmet, never materialized.
Titanium as a material of construction for weapons has found its
greatest application in missiles, as previously described. There were
great hopes at one time for titanium in the rocket launcher (tube) of the
one man Davy Crockett missile weapon system; however, substantial
production of this system never materialized. Titanium also has been
examined for use as shell casings for both small arms ammunition and
large ammunition. This application would appreciably reduce the carry
weight of ammunition. In addition, various titanium applications have
been examined wherein the aim was to reduce the carry weight of articles
to further the mobility of a modern military force. Support equipment
such as water purification units and refrigeration units are in this
category. In addition, there are a number of applications for titanium
in the field of nuclear armaments. None of these can be considered to be
large consumers of titanium and cannot be discussed for. security reasons.
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119
In summary, there have been a number of developmental titanium
ordnance applications that have not advanced to the status of requiring
large quantities of titanium. The largest demand for titanium in the
ordnance category has been for missiles and helicopters, both of which
usually are classified as aerospace applications. The ordnance category
remains ripe with the potential to become a very large market for
titanium, but there are no publicly announced systems that suggest
fruition in the immediate future.
Marine Use s
The use of titanium in items encountering a seawater environment has
been an area of large titanium consumption. Valves, pumps, and piping
for handling seawater on both surface and subsurface ships are the
hardware items in greatest demand. The U.S. Navy program for the
development of deep diving submersible (DDS) vehicles--for exploration,
for rescue, and potentially for weapons systems (limited to research and
development to date)--also has produced a steady demand for limited
amounts of titanium. The titanium (Ti-6Al-4V) buoyancy spheres and the
spherical, thick-wall, pressure hull for the deep submersible Alvin
vehicle are the most representative hardware items in the DDS category.
The Navy research and development program in the area of DDS technology
has resulted in some notable advances in the understanding of titanium
metallurgy. The program continues and the Navy is at a point where the
technology can be applied to production vehicles on a larger scale.
Titanium also has been employed for specific naval ordnance such as
torpedoes, mines, and missiles (missiles, however, generally are included
in the aerospace category). Unconventional marine vehicles such as
hydrofol1 and surface effect vehicles have utilized titanium components
but not on a tonnage production basis. GE's LM-2500 gas turbine engine,
(a derivative of the CF6 aircraft gas turbine engine), which utilizes
about 8,000 lbs (purchased weight) of titanium, powers the Spruance-class
destroyers. There are several engines per ship and several ships have
been launched.
The list of marine uses for titanium generally includes deck fittings
and undefined miscellaneous hardware. Buoys also have been constructed
with titanium as have various dock-side items that are exposed to the
corrosive sea environment . Various marine tools (e. g., underwater
salvage tools) are minor users of titanium. Several pieces of equipment
f or use on of f-shore working platf arms are of titanium construction but
usually are included in the petroleum processing category of industrial
uses .
The discussion of the marine usage of titanium cannot be concluded
wi shout mention of the sporting boat applications. Perhaps the most
famous of these has been the titanium mast application (upper one-third)
on the America's Cup challenger (and winner), the Intrepid. Titanium was
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selected f or the s use because of its preferred strength and modulus
characteristics, but the consumer market for lesser applications is of
more importance in terms of potential future demand for titanium. Items
such as propellers ~ shaf ts, collars ~ struts, steady bearings, transom
bands, rail and roof stanchions, deck plates and a variety of other deck
f ittings, and anchors (Danf orth type) have been produced f ram titanium in
the past. A continuing small market for such items is anticipated.
Industrial Uses
Titanium's growing use in so many applications in several industries
requires that for descriptive purposes, the industrial sectors be listed
as subcategories. For example, titanium is used in the following
industries (the list is not exhaustive):
1.
2.
3.
4.
5.
6.
7.
8.
9. Water purification processing (desalination).
10. Waste processing and disposal.
11. Sports equipment manufacturing.
12. Ground transportation manufacturing.
13. Medical related manufacturing.
14. Miscellaneous manufacturing.
Chemical processing.
Pulp and paper manufacturing.
Textile manufacturing.
Mining and minerals processing industry.
Me tat processing .
Petroleum.
Electricity generation and other energy-related f unc Lions.
Food and drug manuf ac turi ng .
The use of titanium in these industrial subcategories is largely
related to its excellent corrosion-resistance characteristics. However,
there also are industrial applications that are related to titanium's
mechanical and physical properties and frequently to combinations of
several of titanium's features. Generic types of equipment (e.g., heat
exchangers of many different designs and functions) serve the same basic
purpose f ram industry to industry . On the other hand, some types of
titanium items have unique functions for particular industrial needs
(e.g., low-inertia shuttles in weaving machines). The following list of
equipment , more or less using generic terminology ~ illustrates the types
of titanium equipment used:
1. P~mps--housings, impellers, shafts.
2. Va~ves--housings, gates, shafts.
3. Vessels--holding tanks, mixing tanks, reaction towers, pressure
vessels, dif fuser towers, washing tanks.
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Vessel internals--rotating and reciprocating agitators, filter
elements, supports and screens, diffuser tubes, coils,
thermocouple wells, baffle plates, etc.
5. Piping--straight runs, bends and long and short runs of various
diameters, fittings, flanges, terminal nozzles and nozzle
liners, sparser tubes, expansion loops and coils, etc.
6. Heat exchangers--tube bundles in tube-plate terminations, plate
type, bayonet type, tube in shell with coil, helical or
hairpin configurations.
7. Driers and concentrators--spray-type driers, high-speed rotating
atomizer wheels, centrifuges.
8. Conveyors--housings screw on shaft type and endless belt type,
piping for gas or liquid vehicle conveyors.
9. Distillation columns--associated hardware.
10. Fans and shafts--housings.
11. Frames and brackets--clamps and clips, spools, racks and trays,
hooks.
12. Fasteners--threaded bolts and nuts, screws, nails, rivets, wrap
wire.
Corrosion resistance for processing media and reaction products has
been mentioned as the dominating reason for the selection of titanium for
industrial equipment. Titanium is essentially immune to attack in a
variety of media over a considerable temperature range and extended
exposure times. Unalloyed titanium is the material of choice due to its
lowest cost among titanium materials, easy fabricability including
weldability, best corrosion resistance (except for alloys especially
formulated for this purpose such as Ti-0.2Pd and Ti-0.8Ni-0.3Mo alloys),
acceptable mechanical properties, and ready availability in several
product forms. The forms most used are the flat-rolled products and the
roll-and-weld tubing that is produced from strip. Some seamless tubing
is used. Castings are used extensively (e.g., valve housings) and a few
forgings are used. Bar stock and wire use is greater than forging use.
Powder metallurgy products are in use (e.g., for controlled porosity and
permeability filter elements). Counting the roll-and-weld tubing
precursor strip, about seven times as much flat-rolled product is used as
other kinds of product. Table 25 shows the percentages of product forms
used recently in industrial applications. It is noted that while
industrial usage of flat-rolled products is about 86 percent of the total
industrial sheet use, flat-rolled products constitute only about 22
percent of the total mill products manufactured.
Although an exhaustive list of individual industrial applications
would number in the hundreds, and perhaps the thousands, the quantity of
titanium required for such applications has not been large except in the
past 5 to 10 years. In fact, for the first 20 years of titanium's growth
as an industry, only about 10 million lbs of titanium were used in this
category. However, the growth of the use of titanium in the nonaerospace
category has been remarkable over the past 10 years.
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TABLE 25 The 1980 Estimated Utilization of Titanium in the
Industrial Non-aerospace Sector by Product Form
and Approximate Unalloyed Titanium Prices
Composite Prices,
Estimated dollars per poundb
Product Utilization, April April
Form percenta 1979 1981
Tube and pipe 53.0 8.7 5 12 . 50C
Sheet and strip 19 .0 6.25 10 .50
Plate 14 .2 7.20 10.30
Bar and billet 9.5 7 .90 12 . SO
Wire 2.3 14.50 25.00
Castings 2.0 20.00 38.00
a
-
-
Based on the material purchases of one company serving the
industrial uses sector.
Price varies with quantity purchased, grade, dimensions,
surface finish, and other product variables.
Mid-1981 price increased to the $14-15/lb range.
Although continued growth of titanium use is expected in the
industrial use sector, nontechn__al problems possibly could reduce the
growth rate of 12 to 13 percent experienced by this sector of the
titanium market over the past 10 years. The high cost of titanium
products is undoubtedly the leading problem that possibly will inhibit
greater use. A second problem is that insufficient application research
and market development studies have been conducted for the nonaerospace
use of titanium. A third problem, which is somewhat technically
oriented, is related to the question of adequate product availability a
viewed by the potential user.
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REFERENCES
American Society for Metals. 1961. Metals Handbook, 8th ea., Vol. 1,
Properties and Selection of Metals. Metals Park, Ohio: American
Society for Metals.
Fairbairn, G. A., Structural materials f or supersonic transport.
ALLA Paper 64-628 presented at the AIAA Technical Aircraft Design and
Operations Meeting, Seattle, Washington, August 1964.
Goodwin, H. B., 1956. Titanium today. Paper presented to a Chapter
Meeting of the Society for Electrical Engineers. Columbus, Ohio
Jaffee, R. I., 1962. Titanium in 1975. Journal of Metals, Vol. 14,
Pp 588-589.
Materials Advisory Board Titanium Subcommittee of the Committee on
Technical Aspects of Critical and Strategic Materials. 1969. Usage
of Titanium and Its Compounds, with Comments on Scrap and Sponge.
Report MAB-249, Washington, D. C.: National Academy of Sciences.
Minkler, W. W., Review of materials availability issues.
Paper presented at the special meeting of the National Material s
Advisory Board, Washington, D.C., September 3, 1980.
Pratt & Whitney Aircraft, Division of United Aircraft Corporation,
data sheets; late 1960s.
Schapiro, L. and E. Labombard, Nine years of titanium usage.
paper presented at the 6th Anglo-American Aeronautical Conference,
Folkestone, England, September 10, ~ 957. (Reprinted by the Royal
Aeronautical Society in 1959, London, England)., 1957.
Simmons , W . F ., and H. J . Wagner 1970. Current and Future Usage of
Materials in Aircraft Gas Turbine Engines. Defense Metals and
Ceramics Information Center Memorandum 245. Battelle Memorial
Laboratories, Columbus, Ohio.
Titanium Ingot, Mill Products, and Castings, Current Industrial
reports (ITA-991), Bureau of Census, Bureau of Industrial Economics,
Office of Basic Industries, U.S. Department of Commerce,
Washington, D.C.
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Wood, R. A., and H. W. Barr, 197 4 . Current Status of the U.S. Titanium
Industry, A Special Study for the Office of the Director of
Defense Research and Advanced Technology . Metals and Ceramics
Inf ormation Center report MCIC CR-74-01. Battelle Memorial
Laboratories. Columbus, Ohio.
Wood, R. A., 1975. The Titanium Industry in the Mid-1970s ,
Metals and Ceramic Information Center, Report MCIG-75-26
Battelle Memorial Laboratories, Columbus, Ohio.
Representative terms from entire chapter:
turbine engines
