Nondestructive testing of cutting tools thermal firmness

The method for nondestructive determination of instrument thermal firmness under working conditions, is suggested. The method is based on detection of tungsten characteristic K-radiation. The X-ray fluorescence of tungsten, which is a component of high-speed tool steel and which concentration changes under heating, is excited by gamma photons emitted by 57Co (E=123 kev, activity is 108Bq). The method was used for testing milling cutters made of steels R12 and R6M5. The time of strength loss degree measurement in one point is 1.5-2 min. The method provides for examination of instruments of different size depending on working time and conditions.