Surface Roughness Measurements of Titanium Alloy Plates Using Improved Ultrasonic Spectroscopy

A new ultrasonic spectroscopic technique has been developed to fast assess the adhesive surface roughness of aerial titanium alloy (Ti-6Al-4V) plates, which was pretreated by grit blasting. A surface area roughness coefficient s_T has been introduced to specify the 3D topography of a material surface on a quantitative basis. Comprehensive theoretical models based on analyzing the AR parameter spectrum of the received ultrasonic signals have been developed to study the effect of surface on reflected ultrasonic pulses from the adhesive surfaces. When the transducer received a pulse reflected from the titanium alloy surface of the sample, the AR parameter spectrum was compiled. The computer then generated a theoretical curve to match the profile of the spectrum using a theoretical model for surface roughness and a minimization algorithm. The resulting value of the roughness coefficient s_T, representing the best match, was a measure of the surface roughness. A virtual instrument that can obtain and display the roughness coefficient in real time based on a data card is presented. The implemented functions are described. The integrated programming package DRVI was used to design the analyzer.