Moreover, further inspection reveals that the amplitudes are slightly different between the X and Y components; this is caused by the inclination of the measurement directions of the sensor elements from the reference coordinates with respect to the spacecraft spin axis.
Another thermal expansion parameter, the linear thermal expansion coefficient η l(T), was defined as. Figure 1 The schematic description of LTE measurement direction for bulk nanocrystalline ingot iron.
Figure 3 The measurement direction dependence of the parameter A 0 of BNII and CPII Figure 4 The measurement direction dependence of the parameter B and D of BNII and CPII Figure 5 The measurement direction dependence of the parameter C of BNII and CPII.
The measurement direction dependence of the parameters A 0,B,C, and D of BNII and CPII are shown in Figs. 3, 4, and 5, can be obtained by fitting the data of LTE of BNII and CPII with Eq. 3.A 0,C, and D of BNII and CPII are negative values and B of BNII and CPII are positive values.
In 4% of the determinations of ΔCO, the APCO measurement direction and magnitude of change differed more than ± 30% from the measurements by ICO.
LTE of BNII were measured at six directions with different angles at 0° (rolling direction), 30°, 45°, 60°, 75°, and 90° (vertical to rolling direction) against rolling direction on rolling surface, the detailed description of LTE measurement directions for BNII is shown in Fig. 1.
The measurement uncertainty was investigated by analysing the repeatability, measurement direction and the time dependence of the sound source.
Regardless of the measurement direction, αz(T) value is smaller than αx(T) and αy(T) over the entire temperature range.
These differences from real microstructures cause significant computational errors especially when thermal conductivity changes as the function of the measurement direction (parallel or perpendicular).
We can explain qualitatively the results of LTE for BNII and CPII: (1) LTE of BNII at six measurement directions were less than those of CPII because was larger than and was less than ; (2) LET of BNII depend on measurement direction because γ depends on crystal structure and measurement direction.
