熱導率




热导率k{displaystyle k}k是指材料直接传导热能的能力，或称热传导率。热导率定义为单位截面、长度的材料在单位温差下和单位时间内直接传导的熱能。热导率的单位为瓦米-1开尔文-1W mK{displaystyle W over mK}{W over mK}。


热导率k=ΔQAΔtxΔT{displaystyle k={frac {Delta Q}{ADelta t}}{frac {x}{Delta T}}}k={frac {Delta Q}{ADelta t}}{frac {x}{Delta T}} ,其中A{displaystyle A}A是导热体的横截面积，ΔQΔt{displaystyle {frac {Delta Q}{Delta t}}}{frac {Delta Q}{Delta t}}是单位时间内传导的热能，x{displaystyle x}x是两热源间导热体的厚度，ΔT{displaystyle {Delta T}}{Delta T}则是温度差。



物質的熱導率


















































































































物質
物質狀態
 導熱率Wm-1K-1
石墨烯 固態 (4840±440) ~ (5300±480)
金刚石 固態 900 ~ 2320
銀 固態 420
銅 固態 401
黃金 固態 318
鋁 固態 237
白金 固態 70
鐵 固態 80
鋼 固態 60
鉛 固態 35
汞 液態 8.34
冰 固態 2
陶瓷 固態 1.22
玻璃 固態 1.1
水 液態 0.6
聚乙烯 固態 0.3
尼龍 固態 0.2
石蠟油 液態 0.2
石棉 固態 0.2
聚苯乙烯 固態 0.033
軟木塞 固態 0.50
採用在標準狀況下的數據。對於氣體，值是對應於cp。


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