The XRD patterns of the samples prepared by different FJH durations (i.e., TC-1, TC-2, TC-3, and TC-4) are shown in Fig. and coincide with those reported in prior work , confirming the successful synthesis of tungsten carbides in all these samples. Moreover, varying the FJH duration effectively influences the phase compositions such as tungsten (W), WC, and W2C phases in the products and their relative quantities. As shown in Fig. , TC-1 exhibits characteristic peaks located at 34.6º, 38.1º, and 39.5º corresponding to the hexagonal W2C phase , while TC-2, TC-3, and TC-4 display characteristic peaks for both hexagonal WC and W2C phases. This phenomenon suggests that the ratio of WC to W2C peaks increases with the FJH treatment duration, and the characteristic peaks associated with the elemental W disappear when the fabrication duration is longer than 3 s. We believe that the carbon source for the synthesis of tungsten carbides originate from the carbon fiber substrate itself, a similar phenomenon observed in the prior work .