Basic Studies of Plastic Working with Vibration : 1st Report, Ultrasonic Vibro-Indentation Hardness of Carbon Steels

Abstract

In this report, "ultrasonic vibro-Brinell hardness H_ur" is defined in order to estimate the resistance to the plastic deformation of materials under the ultrasonic pulsating loads. The ultrasonic vibro-indentation hardness testing (20 kHz, 500 W, the ratio of the load amplitude and the mean indentation load : P_a/P_m=0.5) of annealed carbon steels (0.15% and 0.55% carbon included respectively) with a spherical indenter, made of hardened steel, was performed. Experimental results show that this testing method is useful as a simulative test of the plastic working under the ultrasonic pulsating compressive load, and that for the same material the differences of the estimating methods of the vibro-indentation load give different results, as "vibro-softening" of "vibro-hardening".