Ultraschallverfahren zur Bestimmung der Anzahl von Einschlüssen in Materialproben — eine kritische Betrachtung empfohlener Methoden

Ultrasonic test procedure to determine the number of inclusions in material samples — a critical analysis of recommended methods. To judge the specific properties of metals one tries to determine the quantity and distribution of the non-metallic inclusions. But the microscopic procedures used so far are destructive and do further not refer to the volume, but rather to the surface of the micrograph sample. Contrary to these methods the inspection by ultrasound is non-destructive and wellsuited for the volumetric detection of inclusions. The possibilities of the ultrasonic pulse-echo-method for cleanliness rating are being checked. Based on the respective results there is a critical view on the ultrasonic test methods which have been recommended so far. Proposals will be made how to make the optimum use of the advantages of the ultrasonic inspection when determining the purity degree of a sample.