February/March_AMP

A D V A N C E D

M A T E R I A L S

P R O C E S S E S | F E B R U A R Y / M A R C H

2 0 1 7

2 5

Fig. 2 —

(a) Phenolic materials research led

to development of the heat shield on the

Mercury Spacecraft; (b) high-temperature

coatings were also employed on the Saturn

1B launch system.

compounds, which still remain import-

ant components of the high-end per-

manent magnet market, used in travel-

ing wave tubes, ion propulsion engines,

magnetic memory applications, and

numerous motor applications. Similar-

ly, the advanced research on compos-

ites provided a new class of materials

with excellent strength, stiffness, and

density properties to compete with

aluminum and steel structures. Early

results were transitioned to the F-111

horizontal stabilizer, engine fan blade,

reentry vehicle structure, satellite an-

tenna disk, and an OV-10 wing box.

ML pioneered carbon-carbon

composites, which were particularly

suitable for very high temperature ap-

plications over long periods of time.

As a result, these composites were

transitioned for use in many aerospace

applications including aircraft brake

disks, solid rocket motor nozzles, space

battery sleeves, missile reentry vehicle

nose tips, turbine engines, and hyper-

sonic flight vehicles.

High temperature work involving

coating technologies also provided

solutions to multiple space related is-

sues during the 1960s. The tungsten-sil-

icide coating developed at ML was suc-

cessfully employed on the second stage

engine of the Saturn 1B launch system,

and a tin-aluminum coating system suc-

cessfully protected thrust engines of the

Agena target vehicle, leading to the his-

toric first linkup of two orbiting space

vehicles. Additional research on abla-

tive materials, including lightweight

beryllium heat shields, provided critical

technology for manned space reentry

capsules, including work on phenolic

materials for the heat protection used

on the Mercury spacecraft (Fig. 2).

During the second half of the

1960s, ML invested in pioneering re-

search to improve high temperature

materials for turbine engines and hy-

personic/supersonic flight. Materials

including high strength titanium and

improved aluminum alloys were devel-

oped and optimized, with results tran-

sitioned to numerous flight systems

including the SR-71 aircraft. Higher

operating temperatures also required

research on greases, oils, and hydraulic

fluids capable of withstanding the in-

creased weapon system temperatures

and improved performance.

Operations in Southeast Asia re-

sulted in severe damage to critical com-

ponents as a result of the increased

speed and performance of aerospace

systems. In particular, radomes, an-

tenna covers, wing leading edges, and

other structural surfaces were dam-

aged during military operations. To ad-

dress this issue, ML created elastomeric

polyurethanes to provide additional

protection for erosion-prone areas. At

the same time, they also developed

fluorocarbon elastomers and provided

thermal flash to protect surfaces during

high temperature operations on ad-

vanced aircraft. The laboratory moved

into its current facilities in the 1980s.

DEVELOPMENTS IN THE 1980s

AND 1990s

As sensors and protection devices

became more critical in the 1980s and

1990s, ML developed mercury cadmi-

um telluride as a detector material for

strategic surveillance and intercept

missions (Fig. 3). The material was used

extensively in target acquisition and

missile guidance. In-house knowledge

of high energy radiation interactions

also established ML as the dominant

international leader in developing pro-

tection against laser weapon radiation.

The laboratory continues to lead this

field, including research on laser-hard-

ened materials to protect satellite and

aircraft components, and advanced op-

tics to protect the human eye. Research

also developed new and improved

radar absorbing materials, which were

transitioned to the B-2 bomber and

F-117 fighter, as well as critical com-

puter modeling programs designed to

provide increasedmaterials casting and

deformation capabilities.

During the 1980s and 1990s, ML

also began extensive research on devel-

oping nanotechnology to provide revo-

lutionary advancements in weaponry,

providing responsive systems that mini-

mize collateral effects and substantially

improve defensive systems. Examples

include efficient chemical/biological

sensors and lighter-weight armor. Re-

searchers also successfully developed

new aluminum-lithium alloys for light-

weight structural applications, and high

temperature gamma titanium alloys for

use in propulsion systems. Consider-

able advancements in the processing of

alpha/beta titanium and precipitation

strengthened nickel alloys were suc-

cessfully transitioned to industry, pro-

viding a dramatic increase in materials

capabilities. Additional improvements

came from development of critical

polyimide resins, including the AFR-

700-B polymer used on the F-17 trailing

edge, and AFR-PE-4 polymer used on

turbine engine applications.

Improvements in aluminum struc-

tural materials provided new 6092/

silicon carbide DRA sheets used for ven-

tral fins on the F-16. The new material

increased stiffness by 40%, extending

component life by four times and sav-

ing $26M in lifecycle costs from reduced

maintenance and system downtime.

Extruded billet of this material also

saved over $100M and improved the re-

sistance to erosion by over seven times

Fig. 3 —

a) Advances in radar absorbing

materials were transitioned to the B-2

bomber; (b) additional research produced

detector materials for use in missile guid-

ance systems.