Fig. 1. (a, c) Morphologies of the W powder by jet mill, (b) size distribution of W powder, (d) morphology of HEA powder.

Fig. 2. Schematic diagram of the process of the LULPS W-HEA.

Fig. 3. SEM-BSE images of the microstructure at the uppermost position of the LULPS W-HEA prepared under different processing parameters of P (1200 W, 1500 W and 1800 W) and V (5 mm/s, 10 mm/s and 20 mm/s). The insets in (a) and (b) show the enlarged images of W phase in corresponding figure.

Fig. 4. SEM images of microstructure of the LULPS W-HEA (a) and the LPS W-HEA (c); (b) and (d) is the enlarged microstructural images and corresponding EBSD inverse pole figure of the LULPS W-HEA; (e) is the TEM figure and corresponding SAED pattern of the LULPS W-HEA, which shows the same pattern to that in the LPS W-HEA.

Fig. 5. Mechanical properties of the LULPS and LPS W-HEA: (a) Quasi-static tensile curves of the LULPS W-HEA and the LPS W-HEA; (b) Strength comparison of LPS WHAs (W-NiFe [1,2,7,10,34,[38], [39], [40]], W-NiFeCo [7,[41], [42], [43], [44], [45]], W-NiFeRe [7], W-NiFeCoMo [46] and W-NiFeY [47]) and the LULPS W-HEA; (c) Dynamic compression curves of the LULPS W-HEA and the LPS W-HEA at ~4 × 103 s - 1; (d) Shear localization in the LULPS W-HEA (d-1) and homogeneous compression in the LPS W-HEA (d-2).

Fig. 6. Pores and W morphologies in the LULPS W-HEA: (a) Effects of P and V on pores; (b) Effects of temperature on liquid content and W morphologies in the schematic W-HEA diagram; Effects of (c) scanning tracks and (d) layers on the distribution of pores; Poor surface fusion forms residual pores; Schematic figure of (e) pores formation between layers, and (f) pores distribution, where the redder position refers to a higher temperature.