Multimodal laser opto-ultrasonic spectroscopy (LOUS) Approach to investigate the impact of elemental composition on the engineering properties of high-density tungsten alloys'

The impact of elemental composition on the engineering properties of high-density tungsten alloy is crucial, particularly in relation to grain size, hardness, elastic modulus, and surface degradation. This study introduces a new multimodal laser opto-ultrasonic spectroscopy (LOUS) technique, which simultaneously integrates the benefits of laser-induced breakdown spectroscopy (LIBS) and laser ultrasonic testing to evaluate the engineering properties of tungsten alloys. The findings indicate that the increasing tungsten concentration significantly enhances the samples' hardness, grain size and elastic modulus. The composition of elements and hardness were assessed using a calibration curve derived from the emission intensity ratio (W-II/W-I) and plasma electron temperature (T_e) in optical emission. The correlation results of (W-II/W-I) and T_e showed significant enhancement with the increase of hardness with a regression coefficient (R² ≥ 0.996), validating the Saha-Eggert relation and underscoring model effectiveness. Additionally, the correlation of the laser ultrasonic testing parameters (attenuation coefficient and velocities) in assessing grain size and elastic modulus showed good reliability (R²≥0.993) when compared to the results obtained from conventional optical microscopy and tensile testing. The results underscore the accuracy and predictive ability of the LOUS method for in-situ characterization.