Super Superelastic Alloys
abrasive wear and fatigue
often lead to life-limiting
bearing and gear failure
in harsh conditions.
Existing materials, such
as hard steels, are prone
to corrosion and rust;
ceramics are non-con-ductive, difficult to manufacture and brittle; and
superalloys are soft and
susceptible to wear and
damage. Working with
Abbott Ball Company,
NASA’s Glenn Research
Center has successfully
developed a set of methods to create high-performance alternatives to conventional bearing materials.
Superelastic Intermetallic Nickel Titanium Alloys and Manufacturing Techniques for Advanced
Bearing Applications builds on work that began in the 1950s to develop nickel-titanium alloys for military use. In 2004, the Abbott Ball-NASA partnership began to develop and refine the binary compound
60Ni Ti, which contains 60% nickel and 40% titanium. Bearing-grade 60Ni Ti is manufactured via a patented
high-temperature powder metallurgy (PM) process. Pre-alloyed Ni Ti alloy powder is hot isostatic pressed
into various shapes and sizes, such as spherical ball blanks, that are then ground, polished and lapped.
Because the PM process yields ball blanks that have isotropic mechanical properties, high-quality bearing
balls can be readily produced. The finished result has a variety of desirable properties: immunity to corrosion and rust, large strain endurance (greater than 5%), high hardness, up to 20% lighter than steel and
wear- and shock-resistance.
◗ NASA Glenn Research Center, www.nasa.gov
Better Protection for Offshore Oil
Increasing demand for oil as an energy
source and sustained prices of oil on
the world market are driving offshore
oil producers to seek new finds further
offshore. One challenge with deep-water
projects is that the emerging oil is much
hotter than the surrounding sea, which
is near freezing, and needs to be kept
warm as it flows through subsea flow
elements and pipes to prevent blockage.
As a result, flow systems on the seafloor
are typically insulated. The Oil Gas &
Mining R&D Div. of The Dow Chemical Company has commercialized an
innovative new insulation product that
can be used in projects that see oil temperatures up to 160 C.
A full end-to-end subsea insulation system, the NEPTUNE Advanced Subsea Flow Assurance
Insulation System offers the widest installation and operating temperature range of any wet insulation
product on the market (- 40 to 160 C), as well as mechanical properties that are designed to accept the rigors
of subsea installation. Two layers provide this level of protection. A Fusion Bonded Epoxy Anti-Corrosion
Coating made of a sprayed and cured solid powder protects the substrate from saltwater corrosion. And the
Flow Assurance Insulation Coating is made from a two-part hybrid polyether thermoset resin that can be
easily cast around a pipe section or flow equipment.
◗ The Dow Chemical Company, www.dow.com
Membrane technologies are crucial in a variety of
separation processes, from biotechnology to energy.
Current membrane developments are bottlenecked
by the “selectivity vs permeability paradox”. That is,
the higher selectivity achieved by use of small pores
(of less than 0.5 nm) is compromised by the lower
permeability flux, and vice versa. This is especially
evident in parasitic energy loss for ethanol-water
separations. A new type of nanomembrane, Oak
Ridge National Laboratory’s High-Performance
Architectured Surface Selective (HiPAS) membranes combine a superhydrophobic surface selectivity layer with an architectured high-flux membrane layer to eliminate this Catch- 22.
Two enabling technologies allow HiPAS to outperform existing zeolite and polymer-based membranes. First, a surface selectivity layer (S-layer)
has been designed with new superhydrophobic/
superhydrophilic technology that allows tunable
wettability without having to reduce pore size
below 1 nm.
Hierarchical pore design minimizes selectivity
loss. Second, an architectured high-flux membrane
layer has been developed with nanochannels that
provide a 104-order-of-magnitude enhancement
of flux over previous technologies. These layers
are placed on top of a porous membrane support
platform suitable for high-throughput industrial
processing. Because the two nanostructured layers
can be integrated with established ORNL inorganic
membranes as supports the potential is good for
scale-up and implementation in follow-on commercialization efforts.
◗ Oak Ridge National Laboratory