Table 4: Characteristics of air pores of the test specimens.

SpecimensMean diameter (μm)Average value of roundness

500-0.40208.01.46
500-0.45216.31.41
500-0.50217.71.37
500-0.55228.11.31
500-0.60256.11.30
800-0.40192.51.40
800-0.45197.61.38
800-0.50217.01.36
800-0.55226.31.30
800-0.60245.61.28