Joining of metallic glasses in liquid via ultrasonic vibrations.

Joining processes especially for metallic materials play critical roles in manufacturing industries and structural applications, therefore they are essential to human life. As a more complex technique, under-liquid joining has far-reaching implications for national defense, offshore mining. Furthermore, up-to-now, the effective joining of metals in extreme environments, such as the flammable organo-solvent or the arctic liquid nitrogen, is still uninvestigated. Therefore, an efficient under-liquid joining approach is urgently called for. Here we report a method to join different types of metallic glasses under water, seawater, alcohol and liquid-nitrogen. The dynamic heterogeneity and liquid-like region expansion induces fluid-like behavior under ultrasonic vibration to promote oxide layer dispersion and metal bonding, allowing metallic glasses to be successfully joined in heat-free conditions, while still exhibiting excellent tensile strength (1522 MPa), bending strength (2930 MPa) and improved corrosion properties. Our results provide a promising strategy for manufacturing under offshore, polar, oil-gas and space environments.

Metallic glue for designing composite materials with tailorable properties.

Developing materials with tailorable properties has been the long-sought goal of humankind. Forming composite materials with superior properties by combining two or more materials has emerged as a competitive means in the search and design of new materials. However, it is still a grand challenge to use metallic materials as a binder for composites because of their lack of adhesion. In the present work, we proposed a facile and flexible route to synthesize composites using metallic glass as a glue to bond various materials, ranging from conductors to insulators, and metals to nonmetals, together. The mechanical, magnetic and electrical performances of the composites can be manually regulated by changing the addition ratios of the metallic glass glue and the corresponding admixture. In addition, porous structures were also obtained and tuned by dissolving the soluble admixture in water. In principle, our approach provides a new idea for the fabrication and optimization of composites using metallic materials as binders. The outcome of our current research opens up a window not only to synthesize composite materials with tailorable properties universally and flexibly, but also towards the discovery of potential multi-functional metal containing composites.