Low thermal stress engineered metal structures
AssigneePowdermet, Inc.
InventorsAndrew Sherman, Brian Werry
Life of this patent
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Abstract
A structured multi-phase composite which include a metal phase, and a low stiffness, high thermal conductivity phase or encapsulated phase change material, that are arranged to create a composite having high thermal conductivity, having reduced/controlled stiffness, and a low CTE to reduce thermal stresses in the composite when exposed to cyclic thermal loads. The structured multi-phase composite is useful for use in structures such as, but not limited to, high speed engine ducts, exhaust-impinged structures, heat exchangers, electrical boxes, heat sinks, and heat spreaders.
Claims45
An engineered multi-phase composite which includes a high thermal conductivity phase comprising boron nitride and an iron-based metal phase, and wherein said high conductivity phase is segregated into isolated pockets forming a discontinuous phase having equivalent spherical dimensions from 10-400 microns in size and from 20-60 vol. % in said engineered multi-phase composite, said metal phase is a continuous phase in said engineered multi-phase composite, said engineered multi-phase composite has a thermal conductivity that is at least 40% greater than the thermal conductivity of said metal that forms said metal phase;
- said high thermal conductivity phase includes a phase change material, said phase change material undergoes a heat-absorbing phase change by melting or vaporization at a temperature of 250-1500° C.
An engineered multi-phase composite which includes a high thermal conductivity phase comprising boron nitride and an iron-based metal phase, and wherein said high conductivity phase is segregated into isolated pockets forming a discontinuous phase having equivalent spherical dimensions from 10-400 microns in size and from 20-60 vol. % in said engineered multi-phase composite, said metal phase is a continuous phase in said engineered multi-phase composite, said engineered multi-phase composite has a thermal conductivity that is at least 40% greater than the thermal conductivity of said metal that forms said metal phase;
- said high thermal conductivity phase is encapsulated with a single or multilayer shell.
An engineered multi-phase composite which includes a high thermal conductivity phase comprising boron nitride and an iron-based metal phase, and wherein said high conductivity phase is segregated into isolated pockets forming a discontinuous phase having equivalent spherical dimensions from 10-400 microns in size and from 20-60 vol. % in said engineered multi-phase composite, said metal phase is a continuous phase in said engineered multi-phase composite, said engineered multi-phase composite has a thermal conductivity that is at least 40% greater than the thermal conductivity of said metal that forms said metal phase;
- said metallic phase also incorporates 1-20 vol. % of additional phases that includes ceramic and/or intermetallic phases that modify at least one thermal and mechanical property of said multi-phase composite selected from the group consisting of elasticity, modulus, strength, density, hardness, corrosion resistance, thermal expansion (CTE), heat capacity, magnetic properties, and electrical properties;
- said additional phases include one or more filler additive particles, said additive particles include metals or ceramics or combinations thereof, wherein said metal includes one or more of nickel, aluminum, iron, chromium, molybdenum, niobium, tungsten, titanium, zirconium copper, hafnium, and alloys thereof, wherein said ceramic includes one or more of graphite, carbides, nitrides, shape memory particles, Cu2O, ZrWO3, beta-eucryptite, LiAlSiO4, ZrO2-ZrWO3, CNT, CNF, Hf(WO4)3, Mg(WO4)3, ZrW2O8, ZrMo2O8, HfW2O8, HfMo2O8, Zeolites, AlPO4, ScF3, HfV2O7, ZrV2O7, Zr2(MoO4)3, CeP2O7, AuP2O7, ScF3, carbon nanotubes, graphene, boron nitride nanosheets, boron nitride nanotubes, cordierite, SiC, Allvar, wherein said metal or ceramic particles includes one or more of hollow spheres, rods, spherical, and/or oblong particles, said metal or ceramic particles having sizes ranging from 1/10th to 2 times the size of said high thermal conductivity phase.
An engineered multi-phase composite which includes a high thermal conductivity phase comprising boron nitride and an iron-based metal phase, and wherein said high conductivity phase is segregated into isolated pockets forming a discontinuous phase having equivalent spherical dimensions from 10-400 microns in size and from 20-60 vol. % in said engineered multi-phase composite, said metal phase is a continuous phase in said engineered multi-phase composite, said engineered multi-phase composite has a thermal conductivity that is at least 40% greater than the thermal conductivity of said metal that forms said metal phase;
- an outer surface of said engineered multi-phase composite includes insulation, and wherein such insulation is rigid or flexible.
A method for forming an engineered multi-phase composite comprising:
- a. providing an iron-based metal material to form a metal phase;
- b. providing a high thermal conductivity material comprising boron nitride wherein
- i. said high thermal conductivity material has at least 40% higher thermal conductivity than said metal phase;
- and,
- ii. said high thermal conductivity material further contains a material having a lower coefficient of thermal expansion (CTE) than that of the metal phase;
- and,
- c. consolidating said high thermal conductivity material with said metal material to form said engineered multi-phase composite,
- wherein the high conductivity material and material having a lower CTE are combined into a composite particle,
- wherein a phase formed by said high thermal conductivity material is discontinuous in said engineered multi-phase composite, said metal phase is a continuous phase in said engineered multi-phase composite, said engineered multi-phase composite has a CTE that is at least 10% less than the CTE of said metal forming said metal phase, said engineered multi-phase composite has a thermal conductivity that is at least 40% greater than a thermal conductivity of said metal that forms said metal phase, and
- forming said engineered multi-phase composite is formed into a thermal managing part, and attaching said thermal managing part to an insulating structure or layer.
Dependencies are inferred from the claim text.