Materials & Manufacturing

Maximizing the natural corrosion resistance of parts and components machined from stainless steels. It can make the difference between satisfactory performance and premature failure. Incorrectly performed, passivation can actually induce corrosion.

An improved method of removing the residues of fabrication from carbon nanotubes has been invented. These residues comprise amorphous carbon and metal particles that are produced during the growth process. Prior methods of removing the residues include a variety of processes that involved the use of...

Rack-mountable composite-material structural components that would serve as both shelves and cold plates for removing heat from electronic or other equipment mounted on the shelves have been proposed as lightweight alternatives to allmetal cold plate/shelves now in use. A proposed cold...

A number of nonvolatile, low-flammability liquid oligomers and polymers based on aliphatic organic carbonate molecular structures have been found to be suitable to be blended with ethylene carbonate to make electrolytes for lithium-ion electro- chemical cells. Heretofore, such electrolytes have often been...

In an improved method of fabricating composite-material structures by laying up prepreg tapes (tapes of fiber reinforcement impregnated by uncured matrix materials) and then curing them, one cures the layups by use of beams of electrons having kinetic energies in the range of 200 to...

Isotropic composites of aluminum alloy matrices reinforced with particulate alumina have been developed as lightweight, high-specific-strength, less expensive alternatives to nickel-base and ferrous superalloys. These composites feature a specific gravity of about 3.45 g/cm3 and specific...

Adhesives that are blends of commercially available urethane and silicone adhesives have been found to be useful for bonding metal parts that flex somewhat during use. These urethane/silicone adhesives are formulated for the specific metal parts to be bonded. The bonds formed by these...

An automatic-control system has been devised for a process in which carbon nanotubes are produced in an arc between a catalyst-filled carbon anode and a graphite cathode. The control system includes a motor-driven screw that adjusts the distance between the electrodes. The system also...

A report describes experiments directed toward the development of paraffin-based hybrid rocket fuels that burn at regression rates greater than those of conventional hybrid rocket fuels like hydroxyl-terminated butadiene. The basic approach followed in this development is to use materials...

A constitutive mathematical model has been developed that predicts the nonlinear thermomechanical behaviors of shape-memory alloys (SMAs) and of shape- memory-alloy hybrid composite (SMAHC) structures, which are composite-material structures that contain embedded SMA actuators. SMAHC...

Tests have shown that modification of chemical compositions can increase the strengths and fracture toughnesses of solid oxide fuel-cell (SOFC) electrolytes. Heretofore, these solid electrolytes have been made of yttria- stabilized zirconia, which is highly conductive for oxygen ions...

Imide copolymers that contain 1,3-bis (3- aminophenoxy) benzene (APB) and other diamines and dianhydrides and that are terminated with appropriate amounts of reactive end caps have been invented. The reactive end caps investigated thus far include 4-phenylethynyl phthalic anhydride...

Inorganic coating materials are being developed to slow or stop corrosion of reinforcing steel members inside concrete structures. It is much simpler and easier to use these coating materials than it is to use conventional corrosion-inhibiting systems based on impressed electric...