常見材料的導熱係數
常見材料（固體、液體和氣體）的導熱係數。
概述
Thermal conductivity (k) quantifies a material's ability to conduct heat. It is defined as the quantity of heat transmitted through a unit thickness, in a direction normal to a surface of unit area, due to a unit temperature gradient under steady-state conditions.
Units: W/(m·K) in SI; Btu/(hr·ft·°F) in Imperial.
Unit conversion: 1 W/(m·K) = 0.5779 Btu/(hr·ft·°F) = 0.85984 kcal/(h·m·°C)
Original Source Text Preservation
The source defines thermal conductivity as a material property and as heat transfer through unit thickness, normal to a unit area, for a unit temperature gradient. It also identifies the common symbols k, λ, and κ, with units W/(m K), J/(s m K), Btu/(hr ft °F), Btu in/(hr ft² °F), and kcal/(h m °C).
The source notes that temperature and pressure influence thermal conductivity, especially for fluids and gases. It also flags asbestos-containing products with a health warning; the restored table retains asbestos rows for historical data completeness, while the safety notes below state that asbestos fibers are hazardous and require qualified controls.
關键公式
Fourier's Law of Heat Conduction
Steady-state conductive heat flux through a flat wall or slab.
Temperature Difference
Where T₁ is the hot-side temperature and T₂ is the cold-side temperature.
變量
| 符號 | 說明 | 單位 |
|---|---|---|
| q/A | Heat flux (heat transfer per unit area) | W/m² |
| k | Thermal conductivity | W/(m·K) |
| ΔT | Temperature difference across material | °C |
| L | Material thickness | m |
Common Material Thermal Conductivities
This selected 25 °C table is a derived summary for quick scanning. The complete original source table, including temperature-specific columns at 25 °C, 125 °C and 225 °C where available, is preserved below.
材料 | Thermal 電導率 (W/(m·K)) | 類別 |
|---|---|---|
| Diamond | 1000 | Crystal |
| Copper | 401 | Metal |
| Aluminum | 215 | Metal |
| Aluminum Brass | 121 | Alloy |
| Iron (wrought) | 80 | Metal |
| Stainless Steel | 17 | Alloy |
| Aluminum Oxide | 30 | Ceramic |
| Agate | 10.9 | Mineral |
| Glass | 1.05 | Amorphous |
| Acrylic | 0.2 | Polymer |
| Acetals | 0.23 | Polymer |
| Water (liquid) | 0.606 | Liquid |
| Acetone | 0.16 | Liquid |
| Air | 0.0262 | Gas |
| Ammonia (gas) | 0.0249 | Gas |
來源: engineeringtoolbox.com
Conduction Calculator
The calculator below is a migration enhancement based on Fourier's law from the source text; it is not presented as an original Engineering ToolBox calculator.
Conductive 熱量 Flux (Flat Wall)
Example: Aluminum vs. Stainless Steel Pot
With a 20 °C temperature difference across a 5 mm wall:
- Aluminum (k = 215 W/(m·K)): q/A ≈ 860,000 W/m²
- Stainless steel (k = 17 W/(m·K)): q/A ≈ 68,000 W/m²
Aluminum conducts roughly 12–13× more heat than stainless steel, which is why aluminum cookware heats faster and more evenly.
Temperature, Pressure and Asbestos Safety Notes from the Source
Thermal conductivity values vary with both temperature and pressure. The source page specifically notes that this is important for fluids and gases such as air, ammonia, carbon dioxide, and water; use temperature- and pressure-specific data when a project depends on accurate heat-transfer calculations.
See also thermal conductivity variations with temperature and pressure, for: Air, Ammonia, Carbon Dioxide and Water.
Asbestos safety note. The source also flags asbestos as a health hazard. Asbestos-containing insulation and boards may have useful thermal conductivity values, but asbestos fibers are dangerous when inhaled and are associated with severe lung disease and cancer. Do not cut, drill, remove, or specify asbestos products without qualified abatement procedures and applicable regulatory controls.
还原的原始源表
The following tables are restored from the original source page to preserve the complete reference data.
Thermal Conductivities common Materials and Products
The restored source table uses three temperature-specific conductivity columns: 25 °C (77 °F), 125 °C (257 °F), and 225 °C (437 °F). Blank cells mean the original source did not provide a value for that material at that temperature.
材料 / substance | 導熱係數 at 25 °C (77 °F) (W/(m K)) | 導熱係數 at 125 °C (257 °F) (W/(m K)) | 導熱係數 at 225 °C (437 °F) (W/(m K)) |
|---|---|---|---|
| Acetals | 0.23 | — | — |
| Acetals | 0.23 | — | — |
| Acetone | 0.16 | — | — |
| Acetylene (gas) | 0.018 | — | — |
| Acrylic | 0.2 | — | — |
| Air, atmosphere (gas) | 0.0262 | 0.0333 | 0.0398 |
| Air, elevation 10000 m | 0.02 | — | — |
| Agate | 10.9 | — | — |
| Alcohol | 0.17 | — | — |
| Alumina | 36 | 26 | — |
| Aluminum | — | — | — |
| Aluminum Brass | 121 | — | — |
| Aluminum Oxide | 30 | — | — |
| Ammonia (gas) | 0.0249 | 0.0369 | 0.0528 |
| Antimony | 18.5 | — | — |
| Apple (85.6% moisture) | 0.39 | — | — |
| Argon (gas) | 0.016 | — | — |
| Arsenic | 50 | — | — |
| Asbestos-cement board1) | 0.744 | — | — |
| Asbestos-cement sheets1) | 0.166 | — | — |
| Asbestos-cement1) | 2.07 | — | — |
| Asbestos, loosely packed1) | 0.15 | — | — |
| Asbestos mill board1) | 0.14 | — | — |
| Asphalt | 0.75 | — | — |
| Balsa wood | 0.048 | — | — |
| Barium | 18.4 | — | — |
| Basalt | 1.67 | — | — |
| Beryllium | 200 | — | — |
| Bismuth | 8.1 | — | — |
| Bitumen | 0.17 | — | — |
| Bitumen/felt layers | 0.5 | — | — |
| Beef, lean (78.9 % moisture) | 0.43 - 0.48 | — | — |
| Benzene | 0.16 | — | — |
| Beryllium | — | — | — |
| Bismuth | 8.1 | — | — |
| Bitumen | 0.17 | — | — |
| Blast furnace gas (gas) | 0.02 | — | — |
| Boiler scale | 1.2 - 3.5 | — | — |
| Boron | 25 | — | — |
| Brass | — | — | — |
| Breeze block | 0.10 - 0.20 | — | — |
| Brick dense | 1.31 | — | — |
| Brick, fire | 0.47 | — | — |
| Brick, insulating | 0.15 | — | — |
| Brickwork, common (Building Brick) | 0.6 -1.0 | — | — |
| Brickwork, dense | 1.6 | — | — |
| Bromine (gas) | 0.004 | — | — |
| Bronze | — | — | — |
| Brown iron ore | 0.58 | — | — |
| Butter (15% moisture content) | 0.2 | — | — |
| Cadmium | — | — | — |
| Calcium | 200 | — | — |
| Calcium silicate | 0.05 | — | — |
| Carbon | 1.7 | — | — |
| Carbon disulfide (gas) | 0.0073 | — | — |
| Carbon dioxide (gas) | 0.0146 | — | — |
| Carbon monoxide (gas) | 0.0232 | — | — |
| Cast iron | — | — | — |
| Cellulose, cotton, wood pulp and regenerated | 0.23 | — | — |
| Cellulose acetate, molded, sheet | 0.17 - 0.33 | — | — |
| Cellulose nitrate, celluloid | 0.12 - 0.21 | — | — |
| Cement, Portland | 0.29 | — | — |
| Cement, mortar | 1.73 | — | — |
| Ceramic materials | — | — | — |
| Chalk | 0.09 | — | — |
| Chamotte, fireclay | 1.4 | — | — |
| Charcoal | 0.084 | — | — |
| Chlorinated poly-ether | 0.13 | — | — |
| Chlorine (gas) | 0.0081 | — | — |
| Chrome Nickel Steel (nickel-chromium steel) | 16.3 | — | — |
| Chromium | — | — | — |
| Chrom-oxide | 0.42 | — | — |
| City/town gas | 0.064 | — | — |
| Clay, dry to moist | 0.15 - 1.8 | — | — |
| Clay, saturated | 0.6 - 2.5 | — | — |
| Coal | 0.2 | — | — |
| Cobalt | — | — | — |
| Cod (83% moisture content) | 0.54 | — | — |
| Coke | 0.184 | — | — |
| Concrete, lightweight | 0.1 - 0.3 | — | — |
| Concrete, medium | 0.4 - 0.7 | — | — |
| Concrete, dense | 1.0 - 1.8 | — | — |
| Concrete, stone | 1.7 | — | — |
| Constantan | 23.3 | — | — |
| Copper | — | — | — |
| Corian (ceramic filled) | 1.06 | — | — |
| Cork board | 0.043 | — | — |
| Cork, re-granulated | 0.044 | — | — |
| Cork | 0.07 | — | — |
| Cotton | 0.04 | — | — |
| Cotton wool | 0.029 | — | — |
| Carbon Steel | — | — | — |
| Cotton Wool insulation | 0.029 | — | — |
| Cupronickel 30% | 30 | — | — |
| Diamond | 1000 | — | — |
| Diatomaceous earth (Sil-o-cel) | 0.06 | — | — |
| Diatomite | 0.12 | — | — |
| Duralium | — | — | — |
| Earth, dry | 1.5 | — | — |
| Ebonite | 0.17 | — | — |
| Emery | 11.6 | — | — |
| Engine Oil | 0.15 | — | — |
| Ethane (gas) | 0.018 | — | — |
| Ethanol vapor | 0.015 | — | — |
| Ether | 0.14 | — | — |
| Ethylene (gas) | 0.017 | — | — |
| Epoxy | 0.35 | — | — |
| Ethylene glycol | 0.25 | — | — |
| Feathers | 0.034 | — | — |
| Felt insulation | 0.04 | — | — |
| Fiberglass | 0.04 | — | — |
| Fiber insulating board | 0.048 | — | — |
| Fiber hardboard | 0.2 | — | — |
| Fire-clay brick 500 oC | 1.4 | — | — |
| Fluorine (gas) | 0.0254 | — | — |
| Foam glass | 0.045 | — | — |
| Dichlorodifluoromethane R-12 (gas) | 0.007 | — | — |
| Dichlorodifluoromethane R-12 (liquid) | 0.09 | — | — |
| Gasoline | 0.15 | — | — |
| Germanium | 59.9 | — | — |
| Glass | 1.05 | — | — |
| Glass, Pearls, dry | 0.18 | — | — |
| Glass, Pearls, saturated | 0.76 | — | — |
| Glass, window | 0.96 | — | — |
| Glass, wool Insulation | 0.04 | — | — |
| Glycerol | 0.28 | — | — |
| Gold | — | — | — |
| Granite | 1.7 - 4.0 | — | — |
| Graphite | 168 | — | — |
| Gravel | 0.7 | — | — |
| Ground or soil, very moist area | 1.4 | — | — |
| Ground or soil, moist area | 1 | — | — |
| Ground or soil, dry area | 0.5 | — | — |
| Ground or soil, very dry area | 0.33 | — | — |
| Gypsum board | 0.17 | — | — |
| Hairfelt | 0.05 | — | — |
| Hardboard high density | 0.15 | — | — |
| Hardwoods (oak, maple..) | 0.16 | — | — |
| Hastelloy C | 12 | — | — |
| Helium (gas) | 0.142 | — | — |
| Honey (12.6% moisture content) | 0.5 | — | — |
| Hydrochloric acid (gas) | 0.013 | — | — |
| Hydrogen (gas) | 0.168 | — | — |
| Hydrogen chloride (gas) | 0.014 | — | — |
| Hydrogen sulfide (gas) | 0.013 | — | — |
| Ice (0 oC, 32 oF) | 2.18 | — | — |
| Indium | 81.6 | — | — |
| Inconel | 15 | — | — |
| Ingot iron | 47 - 58 | — | — |
| Insulation materials | 0.035 - 0.16 | — | — |
| Iodine | 0.44 | — | — |
| Iridium | 147 | — | — |
| Iron | — | — | — |
| Iron-oxide | 0.58 | — | — |
| Kapok insulation | 0.034 | — | — |
| Kerosene | 0.15 | — | — |
| Krypton (gas) | 0.0088 | — | — |
| Lead | — | — | — |
| Leather, dry | 0.14 | — | — |
| Limestone | 1.26 - 1.33 | — | — |
| LInoleum | 0.19 | — | — |
| Lithium | — | — | — |
| Magnesia insulation (85%) | 0.07 | — | — |
| Magnesite | 4.15 | — | — |
| Magnesium | — | — | — |
| Magnesium alloy | 70 - 145 | — | — |
| Marble | 2.08 - 2.94 | — | — |
| Mercury, liquid | — | — | — |
| Methane (gas) | 0.03 | — | — |
| Methanol | 0.21 | — | — |
| Mica | 0.71 | — | — |
| Milk | 0.53 | — | — |
| Mineral wool insulation materials, wool blankets .. | 0.04 | — | — |
| Molybdenum | — | — | — |
| Monel | — | — | — |
| Neon (gas) | 0.046 | — | — |
| Neoprene | 0.05 | — | — |
| Niobium | 53.7 | — | — |
| Nickel | — | — | — |
| Nitric oxide (gas) | 0.0238 | — | — |
| Nitrogen (gas) | 0.024 | — | — |
| Nitrous oxide (gas) | 0.0151 | — | — |
| Nylon 6, Nylon 6/6 | 0.25 | — | — |
| Oil, machine lubricating SAE 50 | 0.15 | — | — |
| Olive oil | 0.17 | — | — |
| Osmium | 87.6 | — | — |
| Oxygen (gas) | 0.024 | — | — |
| Ozone (gas) | 0.019 | — | — |
| Palladium | 70.9 | — | — |
| Paper | 0.05 | — | — |
| Paraffin Wax | 0.25 | — | — |
| Peat | 0.08 | — | — |
| Perlite, atmospheric pressure | 0.031 | — | — |
| Perlite, vacuum | 0.00137 | — | — |
| Phenolic cast resins | 0.15 | — | — |
| Phenol-formaldehyde moulding compounds | 0.13 - 0.25 | — | — |
| Phosphorbronze | 110 | — | — |
| Pinchbeck | 159 | — | — |
| Pitch | 0.13 | — | — |
| Pit coal | 0.24 | — | — |
| Plaster light | 0.2 | — | — |
| Plaster, metal lath | 0.47 | — | — |
| Plaster, sand | 0.71 | — | — |
| Plaster, wood lath | 0.28 | — | — |
| Plasticine | 0.65 - 0.8 | — | — |
| Plastics, foamed (insulation materials) | 0.03 | — | — |
| Platinum | — | — | — |
| Plutonium | — | — | — |
| Plywood | 0.13 | — | — |
| Polyamid | 0.31 | — | — |
| Polycarbonate | 0.19 | — | — |
| Polyester | 0.05 | — | — |
| Polyethylene low density, PEL | 0.33 | — | — |
| Polyethylene high density, PEH | 0.42 - 0.51 | — | — |
| Polyisoprene natural rubber | 0.13 | — | — |
| Polyisoprene hard rubber | 0.16 | — | — |
| Polymethylmethacrylate | 0.17 - 0.25 | — | — |
| Polypropylene, PP | 0.1 - 0.22 | — | — |
| Polystyrene, expanded | 0.03 | — | — |
| Polystyrol | 0.043 | — | — |
| Polyurethane foam | 0.03 | — | — |
| Porcelain | 1.5 | — | — |
| Potassium | 102.4 | — | — |
| Potato, raw flesh | 0.55 | — | — |
| Propane (gas) | 0.015 | — | — |
| Propylene (gas) | 0.017 | — | — |
| Polytetrafluoroethylene (PTFE) | 0.25 | — | — |
| Polyvinylchloride, PVC | 0.19 | — | — |
| Pyrex glass | 1.005 | — | — |
| Quartz mineral | 3 | — | — |
| Radium | 18.6 | — | — |
| Radon (gas) | 0.0033 | — | — |
| Red metal | — | — | — |
| Rhenium | — | — | — |
| Rhodium | — | — | — |
| Rock, solid | 2 - 7 | — | — |
| Rock, porous volcanic (Tuff) | 0.5 - 2.5 | — | — |
| Rock Wool insulation | 0.045 | — | — |
| Roofing paper | 0.19 | — | — |
| Rosin | 0.32 | — | — |
| Rubber, cellular | 0.045 | — | — |
| Rubber, natural | 0.13 | — | — |
| Rubidium | — | — | — |
| Salmon (73% moisture content) | 0.5 | — | — |
| Sand, dry | 0.15 - 0.25 | — | — |
| Sand, moist | 0.25 - 2 | — | — |
| Sand, saturated | 2 - 4 | — | — |
| Sandstone | 1.7 | — | — |
| Sawdust | 0.08 | — | — |
| Selenium | — | — | — |
| Sheep wool | 0.039 | — | — |
| Silica aerogel | 0.02 | — | — |
| Silicon cast resin | 0.15 - 0.32 | — | — |
| Silicon carbide | 120 | — | — |
| Silicon oil | 0.1 | — | — |
| Silimanite | 151 | — | — |
| Silver | — | — | — |
| Slag wool | 0.042 | — | — |
| Slate | 2.01 | — | — |
| Snow (temp < 0 oC) | 0.05 - 0.25 | — | — |
| Sodium | — | — | — |
| Softwoods (fir, pine ..) | 0.12 | — | — |
| Soil, clay | 1.1 | — | — |
| Soil, with organic matter | 0.15 - 2 | — | — |
| Soil, saturated | 0.6 - 4 | — | — |
| Solder 50-50 | 50 | — | — |
| Soot | 0.07 | — | — |
| Steam, saturated | 0.0184 | — | — |
| Steam, low pressure | 0.0188 | — | — |
| Steatite | 2 | — | — |
| Steel, Carbon | — | — | — |
| Steel, Stainless | — | — | — |
| Straw slab insulation, compressed | 0.09 | — | — |
| Styrofoam | 0.033 | — | — |
| Sulfur dioxide (gas) | 0.0086 | — | — |
| Sulfur, crystal | 0.2 | — | — |
| Sulfur hexafluoride | 0.011 | — | — |
| Sugars | 0.087 - 0.22 | — | — |
| Tantalum | — | — | — |
| Tar | 0.19 | — | — |
| Tellurium | 4.9 | — | — |
| Thorium | — | — | — |
| Timber, alder | 0.17 | — | — |
| Timber, ash | 0.16 | — | — |
| Timber, birch | 0.14 | — | — |
| Timber, larch | 0.12 | — | — |
| Timber, maple | 0.16 | — | — |
| Timber, oak | 0.17 | — | — |
| Timber, pitchpine | 0.14 | — | — |
| Timber, pockwood | 0.19 | — | — |
| Timber, red beech | 0.14 | — | — |
| Timber, red pine | 0.15 | — | — |
| Timber, white pine | 0.15 | — | — |
| Timber, walnut | 0.15 | — | — |
| Tin | — | — | — |
| Titanium | — | — | — |
| Tungsten | — | — | — |
| Uranium | — | — | — |
| Urethane foam | 0.021 | — | — |
| Vacuum | 0 | — | — |
| Vanadium | 30.7 | — | — |
| Vermiculite granules | 0.065 | — | — |
| Vinyl ester | 0.25 | — | — |
| Water | 0.606 | — | — |
| Water, vapor (steam) | — | 0.0267 | 0.0359 |
| Wax | 0.084 | — | — |
| Wheat flour | 0.45 | — | — |
| White metal | 35 - 70 | — | — |
| Wood across the grain, white pine | 0.12 | — | — |
| Wood across the grain, balsa | 0.055 | — | — |
| Wood across the grain, yellow pine, timber | 0.147 | — | — |
| Wood, oak | 0.17 | — | — |
| Wool, felt | 0.07 | — | — |
| Wood wool, slab | 0.1 - 0.15 | — | — |
| Xenon (gas) | 0.0051 | — | — |
| Zinc | — | — | — |
| Zirconium | 22.7 | — | — |
來源: engineeringtoolbox.com
原始源圖
The following original source images are preserved to avoid losing visual reference material. When an image contains chart or tabular data, its extracted values are represented in the page tables, calculators, or interactive charts; remaining images are retained as visual source references.
工程要點
- Temperature dependence: Thermal conductivity of gases increases with temperature; for most metals and solids it decreases slightly. Consult temperature-specific data for precision work.
- Overall heat transfer: The conductive flux above is only one part of a real system. Overall heat transfer depends on convective coefficients and radiative exchange on both surfaces. Use the overall heat transfer coefficient U for multi-layer or fluid-coupled problems.
- Anisotropic materials: Wood, composites, and crystals may have different k values along different axes. Use directional conductivity when applicable.
- Asbestos warning: Asbestos has favorable thermal properties but its fibers cause mesothelioma and lung cancer when inhaled. Avoid handling; use safer alternatives.
- Insulation selection: For thermal barriers, low k is desired. Air (k ≈ 0.026 W/(m·K)) and foamed plastics are common insulators.