A mathematical model was established to estimate the contributions of atomic diffusion and plastic deformation to the diffusion bonding of zirconium-based bulk metallic glasses. Additionally, the surface state was introduced into the model since oxide film is the main barrier to atomic bonding across interface. The model calculation displayed that the contribution of plastic deformation to void closure was six orders of magnitude higher than atomic diffusion. The joints with ion etching before bonding were achieved to verify the model. The experimental strength of joints had a sound fit with the theoretical strength calculated by the model.

The development of different efficient flame retardants (FRs) to improve the fire safety of polymers has been a hot research topic. As the concept of green sustainability has gradually been raised to the attention of the whole world, it has even dominated the research direction of all walks of life. Therefore, there is an urgent calling to explore the green and simple preparation methods of FRs. The development of supramolecular chemistry in the field of flame retardancy is expanding gradually. It is worth noting that the synthesis of supramolecular flame retardants (SFRs) based on non-covalent bonds is in line with the current concepts of environmental protection and multi-functionality. This paper introduces the types of SFRs with different dimensions. SFRs were applied to typical polymers to improve their flame retardancy. The influence on mechanical properties and other material properties under the premise of flame retardancy was also summarized.