An Ultrasonic Sieving Method for Classification of Precipitates and Inclusions Extracted from Steels According to the Size

Abstract

In order to measure the size distribution of precipitates and inclusions in steels and to analyze them after classification by the sizes, a wet method was developed for sieving under ultrasonic vibration the residues which were chemically extracted from steels. Ultrasonic vibration prevented small particles of the residues from aggregation and accelerated sieving.
Metallic sieves with openings of from 20 to 2 μ were made by electroplating coarse copper sieves with nickel and platinum. A suitable apparatus to this sieving method was made.
This method was applied to synthetic chromium carbide and the residues extracted from zirconium steel by the acid dissolution method. The reproducibility of sieving was satisfactory. The analytical results of the sieved residues were also discussed.
By this method, about 50 mg of the extracted residues can be sieved in about 25 min with 5, 10, 15 and 20 μ sieves.