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ment of the sample to determine the stress free con-
dition. The object used for this experiment could be
in the form of well heat treated annealed powder sam-
ple. The grains of this sample is thought in the state
of free from all stresses. Another three measurements
are done over the direction according to the illustration
in Figure 4.2. Based on this illustration, the scanning
direction could be summerised as stated in Table 4.3.

Table 4.3: Four scanning conditions required in residual

stress measurement using neutron diffraction method.

Sample ϕψ

Powder (stress free) 0◦ 90◦

Bulk (D1) 0◦ 90◦

Bulk (D2) 90◦ 90◦
Bulk (D3) 0◦ 0◦

The relationship between the measurement direc-
tion describe in Table 4.3 with the multiaxial strain state
affects lattice formation gives the interplanar spacing,d,
given in Equation 4.13.

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