In addition to high specific strength, specific stiffness, excellent thermal conductivity and electromagnetic shielding, magnesium's damping performance is significantly better than most engineering metal materials, even comparable to some commonly used polymer materials, but its strength and heat resistance are significantly higher High-molecular materials, so it has obvious advantages in shock absorption, energy absorption and noise reduction. The strength, stiffness, plasticity and fracture toughness of magnesium and its alloys are still lower than those of steel and aluminum alloys, and their high temperature creep resistance is poor, which restricts their wide application. As we all know, the strength and damping performance of metal materials are in a contradictory inverted relationship. On the one hand, the strength can be improved by limiting the movement of dislocations. On the other hand, damping requires dislocations to move easily and get rid of pinning. The classic material strengthening method must be at the expense of damping performance. How to achieve the toughness and toughness of magnesium and magnesium alloys without significantly increasing the density and reducing the damping performance has become a challenging key scientific issue.
Compared with man-made materials, the macro-mechanical properties of natural biological materials are usually significantly better than the simple sum of their basic structural units. The origin lies in their complex, multi-scale self-assembly structure. Such as shells, bones, etc. present a three-dimensional interpenetrating structure at the microscopic level, and the constituent phases are kept connected and interpenetrating with each other, thereby achieving the complementary advantages of the constituent phases in performance and function, and the simultaneous strengthening and toughening of the materials. The understanding of the magical "structure-performance relationship" in nature provides unique ideas for designing new materials with excellent comprehensive properties.
Recently, in response to the performance requirements for material shock absorption and energy absorption in the fields of aerospace and precision instruments, Liu Zengqian, Zhang Zhefeng, Materials Fatigue and Fracture Laboratory, Institute of Metal Research, Chinese Academy of Sciences, Li Shujun, Yang Rui, Titanium Alloy Research Department, and the University of California, USA Berkeley and the Chinese Academy of Engineering Physics have collaborated to learn from the concept of three-dimensional interpenetrating microstructure of natural biomaterials and melt-impregnated magnesium into the nickel-titanium alloy framework manufactured by additive to build a lightweight, high-strength, high-damping, high-absorption Can magnesium-nickel titanium bionic composite material.