A lightweight, selectively degradable composite material includes a compacted powder mixture of a first powder and a second powder. The first powder comprises first metal particles comprising Mg, Al, Mn, or Zn, having a first particle oxidation potential. The second powder comprises low-density ceramic, glass, cermet, intermetallic, metal, polymer, or inorganic compound second particles. At least one of the first particles and the second particles includes a metal coating layer of a coating material disposed on an outer surface having a coating oxidation potential that is different than the first particle oxidation potential. The compacted powder mixture has a microstructure comprising: a matrix comprising the first metal particles; the second particles dispersed within the matrix; and a network comprising interconnected adjoining metal coating layers that extends throughout the matrix, the lightweight, selectively degradable composite material having a density of about 3.5 g/cm.sup.3 or less.

A lightweight, selectively degradable composite material includes a compacted powder mixture of a first powder and a second powder. The first powder comprises first metal particles comprising Mg, Al, Mn, or Zn, having a first particle oxidation potential. The second powder comprises low-density ceramic, glass, cermet, intermetallic, metal, polymer, or inorganic compound second particles. At least one of the first particles and the second particles includes a metal coating layer of a coating material disposed on an outer surface having a coating oxidation potential that is different than the first particle oxidation potential. The compacted powder mixture has a microstructure comprising: a matrix comprising the first metal particles; the second particles dispersed within the matrix; and a network comprising interconnected adjoining metal coating layers that extends throughout the matrix, the lightweight, selectively degradable composite material having a density of about 3.5 g/cm.sup.3 or less.

A syntactic metal foam composite that is substantially fully dense except for syntactic porosity is formed from a mixture of ceramic microballoons and matrix forming metal. The ceramic microballoons have a uniaxial crush strength and a much higher omniaxial crush strength. The mixture is continuously constrained while it is consolidated. The constraining force is less than the omniaxial crush strength. The substantially fully dense syntactic metal foam composite is then constrained and deformation worked at a substantially constant volume. The deformation working is typically performed at a yield strength that is adjusted by way of selecting a working temperature at which the yield strength is approximately less than the omniaxial crush strength of the included ceramic microballoons. This deformation causes at least work hardening and grain refinement in the matrix metal.

A syntactic metal foam composite that is substantially fully dense except for syntactic porosity is formed from a mixture of ceramic microballoons and matrix forming metal. The ceramic microballoons have a uniaxial crush strength and a much higher omniaxial crush strength. The mixture is continuously constrained while it is consolidated. The constraining force is less than the omniaxial crush strength. The substantially fully dense syntactic metal foam composite is then constrained and deformation worked at a substantially constant volume. The deformation working is typically performed at a yield strength that is adjusted by way of selecting a working temperature at which the yield strength is approximately less than the omniaxial crush strength of the included ceramic microballoons. This deformation causes at least work hardening and grain refinement in the matrix metal.

A structured three-phase composite which include a metal phase, a ceramic phase, and a gas phase that are arranged to create a composite having low thermal conductivity, having controlled stiffness, and a CTE to reduce thermal stresses in the composite when exposed to cyclic thermal loads. The structured three-phase composite is useful for use in structures such as, but not limited to, heat shields, cryotanks, high speed engine ducts, exhaust-impinged structures, and high speed and reentry aeroshells.

A structured three-phase composite which include a metal phase, a ceramic phase, and a gas phase that are arranged to create a composite having low thermal conductivity, having controlled stiffness, and a CTE to reduce thermal stresses in the composite when exposed to cyclic thermal loads. The structured three-phase composite is useful for use in structures such as, but not limited to, heat shields, cryotanks, high speed engine ducts, exhaust-impinged structures, and high speed and reentry aeroshells.

A production method for a titanium alloy member includes preparing a titanium alloy material for sintering as a raw material of a sintered body; nitriding the titanium alloy material for sintering, thereby forming a nitrogen compound layer and/or a nitrogen solid solution layer in a surface layer of the titanium alloy material for sintering and yielding a nitrogen-containing titanium alloy material for sintering; mixing the titanium alloy material for sintering and the nitrogen-containing titanium alloy material for sintering, thereby yielding a titanium alloy material for sintering mixed with nitrogen-containing titanium alloy material; sintering the titanium alloy material for sintering mixed with nitrogen-containing titanium alloy material, thereby bonding the material each other and dispersing nitrogen contained in the nitrogen-containing titanium alloy material for sintering in a condition in which nitrogen is uniformly dispersed into an entire inner portion of the sintered body by solid solution.

A production method for a titanium alloy member includes preparing a titanium alloy material for sintering as a raw material of a sintered body; nitriding the titanium alloy material for sintering, thereby forming a nitrogen compound layer and/or a nitrogen solid solution layer in a surface layer of the titanium alloy material for sintering and yielding a nitrogen-containing titanium alloy material for sintering; mixing the titanium alloy material for sintering and the nitrogen-containing titanium alloy material for sintering, thereby yielding a titanium alloy material for sintering mixed with nitrogen-containing titanium alloy material; sintering the titanium alloy material for sintering mixed with nitrogen-containing titanium alloy material, thereby bonding the material each other and dispersing nitrogen contained in the nitrogen-containing titanium alloy material for sintering in a condition in which nitrogen is uniformly dispersed into an entire inner portion of the sintered body by solid solution.

A composite reinforcement insert includes a strand formed by a central fiber made of ceramic material surrounded by filaments of metal alloy helically wound around the central fiber, and a metal reinforcement layer covering the strand.

A composite reinforcement insert includes a strand formed by a central fiber made of ceramic material surrounded by filaments of metal alloy helically wound around the central fiber, and a metal reinforcement layer covering the strand.