Ultrasonic grain noise modelling Recent applications to titanium alloys inspection

Radu, Iuliana; Zirom-SA; Romania

Tranca, T.; Diac Servicii srl; Romania
Radu, I.; Zirom-SA; Romania

ID: ECNDT-0634-2018
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Present essay try to show some of the most important ecological aspects concerning the
industrial use of Titanium and its alloys. Starting with those regarding its properties, continuing with some technological processes involved in elaborating those materials and ending with the issues regarding recycling processes, titanium challenges scientists and engineers as well because of its remarkable properties that allow special applications in various human activities; but the main issues regarding the technological process of elaborating Titanium or its alloys are followed by those connected with the environments protection and recycling those materials.
It seams that titanium worth all those efforts made by scientists in using it at a larger scale. Researches on those aspects are developed in Romania too.
Over the last several years, many inspection facilities have replaced older immersion inspection equipment with computer-controlled systems that include digital data collection. Prior to the computer-controlled systems, inspections were performed in a stop-on-defect mode where signals that occurred higher than a certain threshold value caused the scanning to stop. The operator would then relocate the indication that caused the signal and evaluate it. The newer systems with digital B and C-scans afford the opportunity for some degree of automated data analysis, including the application of signal-to noise-rejection, which is presented in this report.
The accurate prediction of absolute noise levels requires detailed knowledge of the metal
Micro-structure which enters the model calculations through certain frequency-dependent factors known as “backscatter coefficients”. For a typical industrial inspection of a billet or forging, such information is not generally available, although it could be deduced by analysing backscattered noise waveforms from regions where the microstructure is spatially uniform.
In the absence of specific information it is still possible to use the noise models in a productive manner, namely to predict how changes in the inspection procedure or component geometry will affect the backscattered noise from some microstructure at hand. Such predictions of relative noise properties are the chief topic of this paper.