Ultrasonic testing of laser melting deposited titanium alloy for special equipment

There are high requirements for the pressure-bearing capacity and safety performance of titanium alloy components by using laser melting deposition in the field of special equipment. Due to the special manufacturing process of laser fusion deposition, molded titanium alloy material has a high polycrystalline scattering and attenuation, which seriously affects the detection of the signal-to-noise ratio. A method for processing ultrasonic echo signals based on normalized cross-correlation was proposed in this paper for solving the problem. The ultrasonic full-wave data was normalized and reconstructed according to the correlation coefficient of the reference, and to suppress the noise and extract the weak echo signals at large depths. For pre-buried defective TC11 titanium alloy specimens, ultrasonic C-scan test was performed, and the collected echo signals were processed by normalized cross-correlation method, and the bottom and defect echoes were imaged. Results showed that the normalized cross-correlation method can improve the detection capability of conventional mono-ultrasonic inspection methods for titanium alloy components with large thickness and complex acoustic properties.