Microstructural Control via Copious Nucleation Manipulated by In Situ Formed Nucleants: Large‐Sized and Ductile Metallic Glass Composites

Abstract

A novel strategy to control the precipitation behavior of the austenitic phase, and to obtain large-sized, transformation-induced, plasticity-reinforced bulk metallic glass matrix composites, with good tensile properties, is proposed. By inducing heterogeneous nucleation of the transformable reinforcement via potent nucleants formed in situ, the characteristics of the austenitic phase are well manipulated.

Enhanced Tensile Plasticity in Ultrafine Lamellar Eutectic Al-CuBased Composites with α-Al Dendrites Prepared by Progressive Solidification

“…They proposed two basic principles based on matching fundamental micromechanical characteristics and microstructural length scales to design the ductile BMG composites, which were: (1) introduction of 'soft' elastic/plastic inhomogeneities to initiate local shear banding; and (2) matching of microstructural length scales to the characteristic length scale R P (plastic shielding of an opening crack tip) to suppress the instability propagation of shear bands and micro-cracks. Subsequently, numerous ductile BMG composites with large tensile plasticity were developed [22][23][24][25][26].…”

Local melting to design strong and plastically deformable bulk metallic glass composites

“…4a ). Previous studies have shown that the plastic strain together with a yield strength larger than 1650 MPa is usually up to 14% for CuZr-based BMG composites at room temperature 4 5 7 8 12 13 14 15 16 17 18 19 20 . Our results demonstrate that a significantly higher plastic strain (>14%) without obviously fracture and a yield strength of 1700 ± 10 MPa (see the sample 1 in Fig.…”

“…Until now, only a limited number of fabrication methods have been developed to control the precipitation of B2 CuZr crystals in the glassy matrix, which include optimizing CuZr-based glass-forming compositions 4 5 6 7 8 12 13 , re-melting master alloys before rapid solidification 14 , adjusting applied cooling rates 12 15 16 , controlling casting parameters 17 , and introducing inoculants for heterogeneous nucleation of B2 phase 18 19 . Recently, by applying rapidly heating Cu-Zr-Al amorphous ribbons, the high-temperature B2 CuZr microcrystals in glassy matrix were induced and kept to room temperature 20 , leading to the formation of ductile BMG composites.…”

“…When a BMG is locally and rapidly heated and even melted, the remained matrix is still amorphous by applying a cooling system. Furthermore, it is easy to control the spatial distribution of crystals in the glassy matrix by changing the position of the arc electrode, and to fulfil one of the main requirements for the composites 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 . In this work, this strategy is applied to control the local precipitation of the B2 phase in CuZr-based BMG.…”

Improving plasticity of the Zr 46 Cu 46 Al 8 bulk metallic glass via thermal rejuvenation

“…However, room-temperature brittleness severely restricts their real engineering applications [4]. To address this issue, approaches like elastostatic compression [5,6], ion irradiation [7], shot peening [8] and structure modification [9][10][11][12][13][14][15][16] were applied to improve the plasticity of BMGs. However, these approaches still have their own limitations.…”