一軸圧縮下における超硬合金の超音波減衰について

概要

論文の詳細を見る
Changes of ultrasonic attenuation under uniaxial compression have been investigated for WC-Co alloys containing various cobalt contents and grain sizes by means of a conventional ultrasonic apparatus; the measuring frequency was 10 MHz. The attenuation of the alloys plotted against the amount of prestrain began to increase rapidly above some critical strain. This critical strain increased with increasing Co contents and grain sizes of WC. The ratio of the compressive rupture strain (εr) and the critical strain (εc) invariably remained constant, i.e.εr/εc≅4. Microscopic observations showed that the generation of micro-cracks at grain boundaries is responsible for the increase of the attenuation. Under compressive fatigue stresses, the attenuation increased rapidly after a certain number of fatigue cycles prior to the rupture of the alloy.
社団法人粉体粉末冶金協会の論文