Gradient Microstructures and Mechanical Properties of Ti-6Al-4V/Zn Composite Prepared by Friction Stir Processing

Yuting Lv; Zihao Ding; Xueyan Sun; Lei Li; Gang Sha; Rui Liu; Liqiang Wang

doi:10.3390/ma12172795

Gradient Microstructures and Mechanical Properties of Ti-6Al-4V/Zn Composite Prepared by Friction Stir Processing

Materials (Basel). 2019 Aug 30;12(17):2795. doi: 10.3390/ma12172795.

Authors

Yuting Lv^{1

2}, Zihao Ding², Xueyan Sun¹, Lei Li³, Gang Sha⁴, Rui Liu⁵, Liqiang Wang^{6

7}

Affiliations

¹ College of Mechanical and Electronic Engineering, Shandong University of Science and Technology, Qingdao 266590, Shandong, China.
² State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
³ Key Laboratory of Unconventional Oil & Gas Development, China University of Petroleum (East China), Qingdao 266590, Shandong, China.
⁴ Herbert Gleiter Institute of Nanoscience, Nanjing University of Science and Technology, Nanjing 210094, China.
⁵ National Engineering Research Center for Nanotechnology (NERCN), 28 East JiangChuan Road, Shanghai 200241, China.
⁶ State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China. wang_liqiang@sjtu.edu.cn.
⁷ National Engineering Research Center for Nanotechnology (NERCN), 28 East JiangChuan Road, Shanghai 200241, China. wang_liqiang@sjtu.edu.cn.

Abstract

In this work, a biomedical Ti-6Al-4V (TC4)/Zn composite with gradient microstructures was successfully prepared by friction stir processing (FSP). The microstructures and mechanical properties of the composite were systematically studied using scanning electron microscope (SEM), X-ray diffractometer (XRD), transmission electron microscope (TEM), atom probe tomography (APT), and microhardness test. The results show that TC4/Zn composite can be successfully prepared, and gradient microstructures varying from coarse grain to nanocrystalline is formed from the bottom to the upper surface. During FSP, adding Zn can accelerate the growth of β phase region, and the grain size significantly increases with the increasing rotation rate. The grain combination is the main mechanism for grain growth of β phase region. The deformation mechanisms gradually change from dislocation accumulations and rearrangement to dynamic recrystallization from the bottom to the upper surface (1.5 mm-150 μm from the upper surface). The composite exhibits slightly higher microhardness compared with the matrix. This paper provides a new method to obtain a TC4/Zn composite with gradient surface microstructures for potential applications in the biomedical field.

Keywords: TC4/Zn; composite; friction stir processing; microstructures.