Nano-Gradient Materials Prepared by Rotary Swaging

Abstract

Gradient nanostructured metallic materials with a nanostructured surface layer show immense potential for various industrial applications because of their outstanding mechanical, fatigue, corrosion, tribological properties, etc. In the past several decades, various methods for fabricating gradient nanostructure have been developed. Nevertheless, the thickness of gradient microstructure is still in the micrometer scale due to the limitation of preparation techniques. As a traditional but potential technology, rotary swaging (RS) allows gradient stress and strain to be distributed across the radial direction of a bulk cylindrical workpiece. Therefore, in this review paper, we have systematically summarized gradient and even nano-gradient materials prepared by RS. We found that metals processed by RS usually possess inverse nano-gradient, i.e., nano-grains appear in the sample center, texture-gradient and dislocation density-gradient along the radial direction. Moreover, a broad gradient structure is distributed from center to edge of the whole processed rods. In addition, properties including micro-hardness, conductivity, corrosion, etc., of RS processed metals are also reviewed and discussed. Finally, we look forward to the future prospects and further research work for the RS processed materials.

A novel adjustable magnetorheological fluid gradient material of low frequency vibration isolation: a theoretical and experimental study

“…In equation (15), η is the carrier liquid viscosity and c h is the correction factor, which can be calculated according to equation ( 16)…”

“…The vibration transfer characteristics usually use the vibration level difference as an index [15,16], which can visually represent the attenuation of the vibration energy generated by external excitation at different frequencies of the study object, so it is necessary to investigate the vibration transfer characteristics of MRF under the action of TMF. In this section, we first determine the suitable vibration transfer characteristics index and further calculate the vibration transfer characteristics of MRF based on mechanical impedance to obtain the vibration transfer characteristics of MRF.…”

“…The current research results show that impedance gradient materials have good vibration energy attenuation effects and are wellsuited for vibration control applications. However, impedance gradient materials have the problem of non-adjustable parameters after preparation, which limits the improvement of their performance and further expansion of their use [15,16]. As a magnetically controlled smart material, the mechanical impedance of the MRF can be adjusted by adjusting the magnetic induction strength of the external magnetic field.…”

(Sub)structure Development in Gradually Swaged Electroconductive Bars

“…Because of its incremental character and favorable stress state during processing [40], this method is suitable also for the processing of materials with low plasticity (e.g., Mgbased alloys [41,42] or hardenable Al-based alloys [43,44]), various composites [45,46], or gradient materials [47,48]. It can even be used for postprocessing powder-based materials to enhance compactness, eliminate voids, increase mechanical properties, and extend their lifetime [49,50].…”

A Novel Technique for Controllable Fabrication of Multilayer Copper/Brass Block

“…Copper/brass blocks with micro/nano-multilayered structures are expected to have a high strength, according to previous literatures [3,4], thereby meeting the requirements for the structural components. In addition, pure Cu and Cu alloys had good thermal/electrical conductivities [21][22][23][24]. Thus, a copper/brass block can be used as a structural material in the field of thermal/electrical conductivity applications.…”