Surface Nanocrystallization Treatment for Energy Absorption Device


Hong Kong


The proposed technology relates to a novel energy absorption device design, in which its mechanical properties and energy absorption effect are enhanced by local surface nanocrystalization treatment applied through an ultrasonic impact treatment (UIT) device.   The energy absorption device, consists of surface-treated thin-walled metal tubes, can be used to replace existing energy absorption structures (crash box) in vehicles including automobiles or trains. This results in improved yield stress of treated materials and better deformation characteristics, thereby enhancing the impact / energy absorption capability. The treatment method can be applied on materials including SS304, SS316L, brass, magnesium alloy, aluminium alloy, titanium alloy and zirconium-based alloy. The technology owner has patented the technology (China) and developed prototypes of the energy absorption device. They are currently seeking partnerships with automotive or train/railway manufacturers to test-bed the technology via licensing agreement.


Simple surface treatment process to enhance mechanical properties of materials. For SS304 grade steel, the yield stress after surface nanocrystallization treatment is significantly enhanced by multiple fold, from 252.4MPa to 666.8MPa. The deformation mode is induced and controlled by designing the local surface nanocrystallization layout. Energy absorption capacity can be greatly improved by about 35-70%. For an existing device, the energy absorption efficiency can also be improved through surface nanocrystallization treatment.


This invention can be applied to any energy absorption device design for automobile industries, for any size and configuration of the energy absorption box at front and rear of the vehicle. This invention can be applied to any energy absorption device design for rail vehicle industries, including the energy absorption devices at front, rear and inter-connection of the railway carriages, any nanocrystallized energy absorption devices that are suitable for the rail vehicle conditions can be designed.


The impact crushing covers over 50% of all accidents and it is critical to utilize advanced techniques to enhance the energy absorption performance for safety purposes. Surface nanocrystallization is a new technology to induce specific deformation modes of thin-walled metal and alloy structures, which is different from any conventional methods. This invention is innovative for enhancing energy absorption capability for automobiles and rail vehicles. For this invention, surface nanocrystallization is performed by assembling the UIT equipment with a numerical control machine tool. Any nanocrystallization designed area is digitalized in a computer and nanocrystallization is processed on the specimen automatically. As a result, the local surface nanocrystallization layouts can be produced for practical engineering purposes with cost-saving benefits. The surface nanocrystallization treatment technology surfaced in this invention is a milestone advancement in material engineering. It is expected to become a new driving force for enhancing the performance of material engineering devices and components. It will also be an advanced technology in the emerging manufacturing industries for modern transportation equipment. The engineering significance in practical applications is both immense and far-reaching.