Deformation-driven catalysis of nanocrystallization in amorphous Al alloys

• Rainer J. Hebert,
• John H. Perepezko,
• Harald Rösner and
• Gerhard Wilde

Beilstein J. Nanotechnol. 2016, 7, 1428–1433, doi:10.3762/bjnano.7.134

• while the as-spun sample remained “X-ray amorphous”. These experimental observations strongly suggest that cold rolling affects regions (i.e., spatial heterogeneities) outside shear bands and stimulates the formation of nanocrystals during annealing treatments at temperatures well below the

• crystallization temperature of undeformed ribbons. Keywords: amorphous alloy; annealing; cold-rolling; nanocrystal; shear-band; Findings Crystallization reactions in metallic glasses have been extensively studied due to the beneficial effect of nanocrystal dispersions on mechanical [1][2][3][4] and magnetic

• ], ball milling [14][15][16][24], cold rolling [12][25][26][27][28][29][30][31][32], high-pressure torsion straining [18][33], nanoindentation [34], and uniaxial compression [35]. The results of intense deformation have demonstrated nanocrystals with number densities of up to 1022 m−3 and average sizes of

Nanoglasses: a new kind of noncrystalline materials

• Herbert Gleiter

Beilstein J. Nanotechnol. 2013, 4, 517–533, doi:10.3762/bjnano.4.61

• al. [44] obtained enhanced plasticity in ZrCuNiAl glasses with a heterogeneous microstructure consisting of hard regions surrounded by soft ones. Other approaches, such as cold rolling [44], elastostatic compression [45] or nanometer-sized structural heterogeneities [46][47] have also been shown to

• fracture stresses were also noted if numerous shear bands had been introduced in metallic glasses by cold rolling prior to the deformation tests. Similarly, Takayama [49] observed work-hardening phenomena in highly drawn metallic glass wires, and attributed this behavior to the intersection of shear bands

• band. As a consequence, both nanoglasses deformed homogeneously (Figure 19). A comparable effect has already been reported for metallic glasses that were pre-deformed by cold rolling [48]. In fact, it may be described in a more quantitative way by the strain localization parameter proposed by Cheng et