Figure 1 Metallographs for as annealed Mo in (a), Mo-5Re in (b), Mo-14Re in (c) and Mo-42Re in (d).

As shown in Figure 2a and 2b, the orientation in red grains is [100], in green grains is [110]. Grain with 111 orientation is rarely observed in Mo-14Re and Mo-42Re, meaning textures form during thermal extrusion. The grain size in Mo-42Re is much smaller than in Mo-14Re, suggesting evident grain-fining effect of Re in Mo alloys. Irregular grain boundaries verify that no obvious crystallization occurs. The inserts in Figure 2 show the micrographs of pillar with diameter 2μm and height 4μm.