Analysis of size distribution of inclusions in metal by using single-particle optical sensing method

The spatial size distributions of oxide and/or nitride inclusions on a film filter after chemical or electrolytic extraction have been measured using single-particle optical sensing (SPOS) method in an Fe-10mass%-Ni0.2mass%M (M=Ti and Al) and an Fe-10mass%Ni-0.025mass%Al-0.1 mass %Ti-0.02mass % N al loys. The size distributions obtained from the SPOS method are compared wit h those obtained from the three-dimensional observation of particles on a f ilm filter using scanning electron microscope (SEM) with electron probe mic roanalysis. The volume fractions of particles calculated from the size dist ributions by the SPOS method and SEM observation have been compared with th ose calculated from chemical analysis. It is found that in the size distrib ution measurement the SPOS method is superior to the SEM observation, parti cularly, in the range of d(V) > 5 mum.