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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 | J U N E 2 0 1 6
2 4
Fig. 5 —
Manufacturing steps to produce subscale and custom small arms protective insert (SAPI) plates for female soldiers.
Fig. 6 —
Highly reflective surface of SiC disk
with a theoretical density of >99.7% pro-
duced frompowder materials using FAST.
Extensometers Strain measurement for materials testing Compatible with all major test systems • Measuring ranges from 1% to 2000% strain • Gauge lengths from 0.125 to 10+ inches (3 to 250+ mm) • Temperature ranges from -265 to 1600°C • Laser extensometers 3975 South Highway 89 Jackson, WY 83001 USA 307 733-8360 www.epsilontech.com Over 30 models to cover all common tests ISO 170252013.15 AMP Dir b&w ad_2002.02 ad 1/2/14 10:41 AM Page 1
path, and delays penetration, which
also indicates dispersion of the incom-
ing focused energy across interfaces
within the ceramic tiles. FAST is an
enabling technology to custom man-
ufacture SAPI (small arms protective
insert) plates (body armor) for female
soldiers, both quickly and cost effec-
tively (Fig. 5).
Lightweight, thermally managed
optics for space applications.
SiC and
B
4
C offer a beneficial combination of
physical and mechanical properties
including high hardness, resistance
to contamination, light weight, sta-
bility in ionizing radiation, and good
elastic modulus. B
4
C is an excellent
lightweight material for mirrors. Its
high elastic modulus (460 GPa) and low
density (2.52 g/cm
3
) provide a modulus-
to-density ratio (specific modulus)
that exceeds SiC, beryllium, and other
ceramic materials. It can be finished to
better than 19 Å, and provides a bidirec-
tional reflectance distribution function
suitable for many applications.
Currently, SiC mirrors are pro-
duced using chemical vapor deposi-
tion (CVD) at elevated temperatures.
CVD produces a columnar structure
with intergranular porosity, which is
removed by hot isostatic pressing (HIP)
at elevated temperature. The combina-
tion of CVD and HIP contributes to high
cost and long lead times. These issues
are addressed by using SiC powder
followed by compaction and sintering
using FAST, producing dense SiC disks
with a theoretical density >99% and a
submicron polycrystalline microstruc-
ture (Fig. 6). After fine polishing, the SiC
disk surface exhibits properties similar
to highly reflective optics.
SUMMARY
FAST is an enabling manufac-
turing technology to produce metal,
ceramic, and composite components
with tailored properties using a pow-
der metallurgy approach. In many
cases, it is a one-step, cost-effective
manufacturing process. The technol-
ogy is ready to be transferred to private
industry for production of net-shape
components.
~AM&P
For more information:
Jogender
Singh is director, FAST-Center of
Excellence, Department of Materials
Science and Engineering, Pennsylva-
nia State University, University Park, PA
16801, 814.863.9898,
jxs46@psu.edu,
www.psu.edu.
performance. Tailoring B
4
C chemistry
reduces stress-induced phase transfor-
mation, changes the crack propagation