Mg-Al-Zn系镁合金在大气中的散热性能研究

Atmospheric Heat Dispersion Research of Mg-Al-Zn Magnesium Alloys

摘要:

在20~220℃范围内对比研究了AZ80、AZ31、ZK60镁合金和AA6082铝合金在大气中的散热性能，分别测量其环境散热曲线并用指数型热动力学方程T=T0+ΔT0·exp（-t/A0）拟合。结果表明，固溶处理可使铸态或挤压态镁合金热导率下降，而固溶+时效处理后其热导率有所提升。分析了瞬时温差与瞬时温度比值ΔT/T与镁合金、铝合金散热性能的关系，自然对流条件下，柱高对AZ80镁合金散热性能影响较小；在人工强制对流条件下，当0.25<ΔT/T<0.45时，高柱（60mm）散热速率约为低柱（20mm）的两倍。在自然对流条件下，AZ80、AZ31镁合金的散热性能在0.25<ΔT/T<0.45（120~220℃）时，明显优于AA6082铝合金。在0.05<ΔT/T<0.25（20~120℃）时，这三种合金的散热性能无明显差别。

Abstract:

The atmospheric heat dispersion of magnesium alloys AZ80、AZ31、ZK60 and aluminum alloys AA6082 were measured. It was apparently that the thermal dispersion curves of the columnar model can be exponential fitted as T=T0+ΔT0·exp(-t/A0). The result shows that the solution treatment can make the thermal conductivity of the magnesium alloys decrease. However, the solutionizing plus aging treatment can make the thermal conductivity increase. The relationship between ΔT/T and the heat dispersion rate was also studied. The heat dispersion rate of high columns (60mm) is about two times that of low columns (20mm) in the condition of forced air convection, while there is no obvious difference in the condition of natural convection. Moreover, the dispersion properties of these alloys can be evidently dived into two regions by ΔT/T in natural convection. There was no much difference among AZ80、AZ31、AA6082 alloys when 0.05<ΔT/T<0.25 (20~120℃), while the AZ80 and AZ31 exhibited more preferential performance than AA6082 alloys when 0.25<ΔT/T<0.45 (120~220℃).