Some variations provide a metal-alloy biphasic system containing a first metal M.sup.1 and a second metal M.sup.2, wherein a second metal phase has a melting temperature lower than that of a first metal phase, and wherein the metal-alloy biphasic system has a hierarchical microstructure containing a second length scale that is at least one order of magnitude smaller than a first length scale. Some variations provide a metal-alloy biphasic system containing a first metal M.sup.1 and a second metal M.sup.2, wherein a second metal phase has a melting temperature lower than that of a first metal phase, and wherein the first metal phase forms a continuous network. Other variations provide a metal-alloy biphasic powder containing at least a first metal and a second metal, wherein the solubility of first metal in second metal is less than 5%. Methods of making and using the powders and biphasic system are disclosed.

Polycrystalline diamond cutting elements having enhanced thermal stability, drill bits incorporating the same, and methods of making the same are disclosed herein. In one embodiment, a cutting element includes a substrate having a metal carbide and a polycrystalline diamond body bonded to the substrate. The polycrystalline diamond body includes a plurality of diamond grains bonded to adjacent diamond grains by diamond-to-diamond bonds and a plurality of interstitial regions positioned between adjacent diamond grains. At least a portion of the plurality of interstitial regions comprise lead or lead alloy, a catalyst material, metal carbide, or combinations thereof. At least a portion of the plurality of interstitial regions comprise lead or lead alloy that coat portions of the adjacent diamond grains such that the lead or lead alloy reduces contact between the diamond and the catalyst.

Polycrystalline diamond cutting elements having enhanced thermal stability, drill bits incorporating the same, and methods of making the same are disclosed herein. In one embodiment, a cutting element includes a substrate having a metal carbide and a polycrystalline diamond body bonded to the substrate. The polycrystalline diamond body includes a plurality of diamond grains bonded to adjacent diamond grains by diamond-to-diamond bonds and a plurality of interstitial regions positioned between adjacent diamond grains. At least a portion of the plurality of interstitial regions comprise lead or lead alloy, a catalyst material, metal carbide, or combinations thereof. At least a portion of the plurality of interstitial regions comprise lead or lead alloy that coat portions of the adjacent diamond grains such that the lead or lead alloy reduces contact between the diamond and the catalyst.

Provided in one embodiment is a method of identifying a stable phase of an ordering binary alloy system comprising a solute element and a solvent element, the method comprising: determining at least three thermodynamic parameters associated with grain boundary segregation, phase separation, and intermetallic compound formation of the ordering binary alloy system; and identifying the stable phase of the ordering binary alloy system based on the first thermodynamic parameter, the second thermodynamic parameter and the third thermodynamic parameter by comparing the first thermodynamic parameter, the second thermodynamic parameter and the third thermodynamic parameter with a predetermined set of respective thermodynamic parameters to identify the stable phase; wherein the stable phase is one of a stable nanocrystalline phase, a metastable nanocrystalline phase, and a non-nanocrystalline phase.

Provided in one embodiment is a method of identifying a stable phase of an ordering binary alloy system comprising a solute element and a solvent element, the method comprising: determining at least three thermodynamic parameters associated with grain boundary segregation, phase separation, and intermetallic compound formation of the ordering binary alloy system; and identifying the stable phase of the ordering binary alloy system based on the first thermodynamic parameter, the second thermodynamic parameter and the third thermodynamic parameter by comparing the first thermodynamic parameter, the second thermodynamic parameter and the third thermodynamic parameter with a predetermined set of respective thermodynamic parameters to identify the stable phase; wherein the stable phase is one of a stable nanocrystalline phase, a metastable nanocrystalline phase, and a non-nanocrystalline phase.

While a molten metal obtained by melting silver and a metal, which is selected from the group consisting of tin, zinc, lead and indium, in an atmosphere of nitrogen is allowed to drop, a high-pressure water (preferably pure water or alkaline water) is sprayed onto the molten metal in the atmosphere or an atmosphere of nitrogen to rapidly cool and solidify the molten metal to produce a silver alloy powder which comprises silver and the metal which is selected from the group consisting of tin, zinc, lead and indium and which has an average particle diameter of 0.5 to 20 m, the silver alloy powder having a temperature of not higher than 300 C. at a shrinking percentage of 0.5%, a temperature of not higher than 400 C. at a shrinking percentage of 1.0% and a temperature of not higher than 450 C. at a shrinking percentage of 1.5% in a thermomechanical analysis.

Polycrystalline diamond cutting elements having enhanced thermal stability, drill bits incorporating the same, and methods of making the same are disclosed herein. In one embodiment, a cutting element includes a substrate having a metal carbide and a polycrystalline diamond body bonded to the substrate. The polycrystalline diamond body includes a plurality of diamond grains bonded to adjacent diamond grains by diamond-to-diamond bonds and a plurality of interstitial regions positioned between adjacent diamond grains. At least a portion of the plurality of interstitial regions comprise lead or lead alloy, a catalyst material, metal carbide, or combinations thereof. At least a portion of the plurality of interstitial regions comprise lead or lead alloy that coat portions of the adjacent diamond grains such that the lead or lead alloy reduces contact between the diamond and the catalyst.

Polycrystalline diamond cutting elements having enhanced thermal stability, drill bits incorporating the same, and methods of making the same are disclosed herein. In one embodiment, a cutting element includes a substrate having a metal carbide and a polycrystalline diamond body bonded to the substrate. The polycrystalline diamond body includes a plurality of diamond grains bonded to adjacent diamond grains by diamond-to-diamond bonds and a plurality of interstitial regions positioned between adjacent diamond grains. At least a portion of the plurality of interstitial regions comprise lead or lead alloy, a catalyst material, metal carbide, or combinations thereof. At least a portion of the plurality of interstitial regions comprise lead or lead alloy that coat portions of the adjacent diamond grains such that the lead or lead alloy reduces contact between the diamond and the catalyst.

The invention discloses the internal structures and processes to synthesize the structure of self-healing materials, especially metallic materials, metal matrix micro and nanocomposites. Self-healing is imparted by incorporation of macro, micro or nanosize hollow reinforcements including nanotubes, filled with low melting healing material or incorporation of healing material in pockets within the metallic matrix; the healing material melts and fills the crack. In another concept, macro, micro and nanosize solid reinforcements including ceramic and metallic particles, and shape memory alloys are incorporated into alloy matrices, specially nanostructured alloy matrices, to impart self healing by applying compressive stresses on the crack or diffusing material into voids to fill them. The processes to synthesize these self-healing and nanocomposite structures, including pressure or pressureless infiltration, stir mixing and squeeze casting in addition to solid and vapour phase consolidation processes are part of this invention.

The invention discloses the internal structures and processes to synthesize the structure of self-healing materials, especially metallic materials, metal matrix micro and nanocomposites. Self-healing is imparted by incorporation of macro, micro or nanosize hollow reinforcements including nanotubes, filled with low melting healing material or incorporation of healing material in pockets within the metallic matrix; the healing material melts and fills the crack. In another concept, macro, micro and nanosize solid reinforcements including ceramic and metallic particles, and shape memory alloys are incorporated into alloy matrices, specially nanostructured alloy matrices, to impart self healing by applying compressive stresses on the crack or diffusing material into voids to fill them. The processes to synthesize these self-healing and nanocomposite structures, including pressure or pressureless infiltration, stir mixing and squeeze casting in addition to solid and vapour phase consolidation processes are part of this invention.