Analysis of Residual Stress Effect in Wear-In Procedure Using Utrasonic Backward Radiation

Abstract

The characteristics of the Rayleigh surface wave are investigated indirectly by measuring the angular dependency of the backward radiation of the incident ultrasonic wave in the scuffing specimens, and then compared to the residual stress distribution. The peak intensity of the backward radiation profile decreases and the right half width of the profile increases as the increase in the variation of residual stress distribution for the scuffing specimen. The peak intensity and angle depend on the amount of residual stress as well as the inhomogeneity in microstructure that causes scattering during the propagation of the surface waves. The perturbation theory about SAW dispersion was applied to understand the break-in procedure. The result observed in this study demonstrates high potential of the backward radiated ultrasound as a tool for nondestructive evaluation of the subsurface gradients of materials.

Characterization of TiN coating layers using ultrasonic backward radiation

“…1. The previous works [6,7] successfully reported very good correlations between the parameters (such as peak amplitude, peak angle and width) of ultrasonic backward radiation profiles and the material degradation parameters of interrogated specimens, since the formers were closely related to the wave scattering and dispersion characteristics of surface region of a test piece under interrogation [8].…”

“…Previously the ultrasonic backward radiation has been measured for the nondestructive evaluation of various test pieces with subsurface gradients in their properties due to corrosion, wear and creep [6,7]. In the previous works, to describe the extent of degradation occurred in the test pieces it has been observed the ''ultrasonic backward radiation profile,'' which presents a variation in the peak amplitude of a ultrasonic backward radiation signal (captured at a certain incident angle) according to an incident angle of radiation beam (in water) from a sending transducer in an immersion test setup as shown in Fig.…”