LFA 457 MicroFlash

– Performance

Copper and Aluminum Pure metal samples are excellent for checking the performance of a laser flash device. Presented in the figure are the thermal diffusivity results measured on pure copper (99.999%) and pure aluminum (99.9%) between room temperature and 600°C. The results are compared with literature values taken from the TPRC database (lines). The literature values have a stated uncertainty of ±4% (error bars). However, the measurement results achieved with the
TM generally are in agreement within ±2% withthe values given in literature. Stainless Steel Stainless steel (SRM 1461) is a reliable standard material for checking the performance of thermophysical properties testing equipment up to high temperatures. Presented here are the measured thermal diffusivity and thermal conductivity of an NIST thermal conductivity standard reference material (SRM 1461). Additionally shown are the thermal conductivity values of the corresponding NIST certificate together with the stated uncertainty. The results achieved with the LFA 457 are clearly well within the given uncertainty range.

LFA 457 MicroFlash

– Applications

Polycrystalline Graphite Graphite materials are known to show a maximum thermal conductivity around room temperature, which can easily be analyzed using the low temperature version of the LFA 457. The physical explanation for this maximum is the high Debye temperature of this material (>1000K). The decrease in thermal diffusivity with increasing temperature dominates the temperature dependence of the thermal conductivity in the high temperature region. The specific heat decreases strongly at temperatures below room temperature and dominates the temperature dependence of the thermal conductivity there. 6