Accession Number : ADD016126

Title :   Method for Producing Closed Cell Spherical Porosity in Spray Formed Metals.

Descriptive Note : Patent, Filed 11 Aug 92, patented 30 Nov 93,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Kelley, Paul

Report Date : 30 Nov 1993

Pagination or Media Count : 12

Abstract : Metal and metal alloy preforms having closed cell, spherical porosity are spray formed at high deposition rates by introducing blowing agents into the thixotropic semisolid deposition layer, within which gas formed in thermal decomposition reactions are trapped. Density reductions of nearly 30% were generated in a phosphor bronze matrix, using barium carbonate as the blowing agent. Hollow glass particles were produced in the same matrix alloy by injection of microsphere precursor frit containing sulfur. A simple Newtonian heat transfer model of agent heating in the spray predicts agent/matrix compatibility. Along with modest improvements in damping capacity, tensile and compressive properties were found to be equal or superior to powder metallurgy product at the same porosity levels.

Descriptors :   *BARIUM, *CARBONATES, *METALS, *POROSITY, *SPRAYS, *PATENTS, *SPHERES, ALLOYS, BRONZE, CELLS, COMPATIBILITY, COMPRESSIVE PROPERTIES, DAMPING, DECOMPOSITION, DENSITY, DEPOSITION, FRIT, GLASS, HEAT TRANSFER, INJECTION, LAYERS, MICROSPHERES, MODELS, PARTICLES, PHOSPHORS, POWDER METALLURGY, PRECURSORS, RATES, REDUCTION, SULFUR, TRANSFER, SOLIDS, GASES, ACOUSTICS, THERMAL PROPERTIES, TENSILE PROPERTIES

Subject Categories : Properties of Metals and Alloys
      Inorganic Chemistry
      Thermodynamics
      Miscellaneous Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE