| RESEARCH PAPER |
|
|
|
|
|
| Effect of High-energy Shot Peening Treatment on Micro-structure and Properties of 7A52 Aluminum Alloy |
| CHEN Chao, CHEN Furong, XIE Ruijun, LU Yao
|
| School of Materials Science and Engineering,Inner Mongolia University of Technology, Hohhot 010051; |
|
|
|
|
Abstract With the development of surface self-nanocrystallization technology of metallic materials, the metallic surface pro-perties have been enhanced to a certain degree. In this paper, the mechanism of surface nanocrystallization on 7A52 aluminum alloy after high-energy shot peening treatment (HESP) was characterized by SEM, EBSD,TEM and HRTEM. The results show that the microhardness increase with the increase of shot peening time. After 50 min HESP, the surface hardness is about 270HV, which can approximately increase to 1.5 times compared to the base metal; the average grain size is about 14.16 nm; the subsurface layer of 60 μm deep is composed of micrometers sub-grains. The surface layer grain refinement process of 7A52 aluminum alloy involves formation of dislocation pile-up and tangling, which resulted in deformed grains. Finally, nano-scale grains with equiaxed shape and random crystallographic orientations are formed upon the multidirectional repeated loads.
|
|
Published: 04 May 2018
|
|
|
|
|
1 Huang L, Lu J, Troyon M. Nanomechanical properties of nanostructured titanium prepared by SMAT[J]. Surf Coat Technol,2006,201(201):208.
2 Lin Y, Lu J, Wang L, et al. Surface nanocrystallization by surface mechanical attrition treatment and its effect on structure and properties of plasma nitrided AISI 321 stainless steel[J]. Acta Mater,2006,54(20):5599.
3 Zhou L, He W, Luo S, et al. Laser shock peening induced surface nanocrystallization and martensite transformation in austenitic stainless steel[J]. J Alloys Compd,2016,655:66.
4 Dai K, Villegas J, Shaw L. An analytical model of the surface roughness of an aluminum alloy treated with a surface nanocrystallization and hardening process[J]. Scr Mater,2005,52(4):259.
5 Dai K, Villegas J, Stone Z, et al. Finite element modeling of the surface roughness of 5052 Al alloy subjected to a surface severe plastic deformation process[J]. Acta Mater,2004,52(20):5771.
6 Zhao K, Liu Y, Yao T, et al. Surface nanocrystallization of Ti-45Al-7Nb-0.3W intermetallics induced by surface mechanical grin-ding treatment[J]. Mater Lett,2016,166:59.
7 Ren X D, Huang J J, Zhou W F, et al. Surface nano-crystallization of AZ91D magnesium alloy induced by laser shock processing[J]. Mater Des,2015,86:421.
8 张晓燕. 材料科学基础[M].北京:北京大学出版社,2009. |
|
|
|
渝公网安备50019002502923号 © Editorial Office of Materials Reports.
2017, Vol. 31 
