中国物理B ›› 1998, Vol. 7 ›› Issue (6): 451-457.doi: 10.1088/1004-423X/7/6/007
吴柏枚1, 杜英磊2, 秦晓英3, 张立德3
DU YING-LEI (杜英磊)a, WU BAI-MEI (吴柏枚)b, QIN XIAO-YING (秦晓英)c, ZHANG LI-DE (张立德)c
摘要: The thermal diffusivities of nanostructured NiAl (n-NiAl) alloys wit h different relative densities and the polycrystalline NiAl alloy are measured by using photoacoustic technique in which the signal is detected at the front surface while the rear-surface is excited. It is shown that the values of thermal diffusivity of the nanostructured NiAl alloy are lower than that of the polycry stalline NiAl alloy. The thermal diffusivities of n-NiAl alloys decrease with t he decrease of their relative densities when they are over 70%. When the relativ e density of n-NiAl alloys is lower than 70%, an anomalous increase of thermal diffusivity is observed, which indicates there exists a critical excess volume ΔVc (or critical relative density) in n-NiAl alloys near 70%. Th e results are discussed.
中图分类号: (Thermal diffusivity)