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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 | S E P T E M B E R 2 0 1 5
1 0 METALS | POLYMERS | CERAMICS
HIGH-STRENGTH STEEL
SHEET SUITS AUTOMOTIVE
APPLICATIONS
Several hot rolled medium carbon-
manganese-boron steel sheets with ten-
sile strength of 200-220 ksi after hot
stamping and quenching are currently
used to make safety and structural com-
ponents on automobiles. However, a
newly designed medium carbon, hot
rolled high-strength steel sheet (HPHSS)
was recently developed to exceed the
strength of C-Mn-B sheet. This HPHSS
sheet can be used in hot stamping of
safety and structural parts, truck frames,
and other high stressed components.
Additional uses for the new sheet in-
clude defense, oil and gas, and con-
struction applications.
Uncoated HPHSS sheet has suffi-
cient corrosion resistance to minimize
surface loss after hot stamping and wa-
ter quenching—only post-stamp paint-
ing is required. HPHSS sheet for special
applications can be coated by galva-
nizing, galvannealing, aluminizing, or
other standard coating processes. After
stamping, components are subjected to
quenching and tempering to reach the
desired combination of strength, fatigue
strength, and impact strength. Produc-
tion costs of uncoated HPHSS sheet are
15-20% higher than costs associated
with C-Mn-B sheet. High specific tensile
strength provides significant weight re-
duction compared to aluminum alloy
sheets. For example, 0.08-in. thickness
hardened HPHSS sheet substitutes at
least 0.45-in. thickness hardened 6xxx
series aluminum alloy sheet with a pro-
jected weight reduction of at least 48%
without sacrificing stiffness and durabil-
ity.
ROBOT TO 3D PRINT A
STEEL BRIDGE
Dutch designer Joris Laarman cre-
ated a new research and development
company called MX3D, which special-
izes in building six-axis robots that can
3D print metal and resin in mid-air. The
technique allows for large-scale objects
like infrastructure to be printed in the
exact spot where they live, which has
vast implications for the construction
industry and opens up a wealth of new
design possibilities.
The finished bridge will be ap-
proximately 24 ft long, support normal
Amsterdam foot traffic, and feature an
intricate design that looks more hand-
crafted than the detailing on most
bridges. Because 3D printing allows for
more granular control of detail than
traditional industrial manufacturing,
designs can be much more ornate.
Most 3D printers use resin or plastic to
construct objects. This bridge will be
made of a new steel composite created
by the University of Delft. As strong as
regular steel, it can be dolloped out by a
3D printer, drop by drop. The result? A
3D printed bridge as strong as any oth-
er, Laarman says. .
SMART MATERIALS
CAMOUFLAGE LIKE SQUID
Researchers from the Universi-
ty of Bristol, UK, created artificial skin
that can be transformed at the flick of a
switch to mimic one of nature’s masters
of camouflage—the squid. The team
Dutch startup company MX3D plans to build the world’s first 3D printed bridge
across an Amsterdam canal.
BRIEF
Operations will begin soon at Carpenter Technology Corp.’s new superalloy powder facility in Alabama as part of a
multilevel agreement with United Technologies Corp.’s (UTC) Pratt & Whitney Division. Carpenter will supply Pratt
& Whitney with superalloy powder for up to 20 years once qualifications are satisfied. As part of the agreement, UTC’s
aerospace business units agreed to purchase alloy steel bar/billet, nickel superalloy powder, stainless bar/billet,
and strip laminate products from Carpenter for a period of 10 years. Carpenter currently supplies UTC’s aerospace busi-
nesses with a portion of their overall demand for nickel, stainless, and strip laminate products.