A nanocrystalline-amorphous mixed layer obtained by ultrasonic shot peening on pure titanium at room temperature

Lihua Zhu; Yanjin Guan; Jun Lin; Jiqiang Zhai; Zhendong Xie

doi:10.1016/j.ultsonch.2018.04.017

A nanocrystalline-amorphous mixed layer obtained by ultrasonic shot peening on pure titanium at room temperature

Ultrason Sonochem. 2018 Oct:47:68-74. doi: 10.1016/j.ultsonch.2018.04.017. Epub 2018 Apr 27.

Authors

Lihua Zhu¹, Yanjin Guan², Jun Lin³, Jiqiang Zhai⁴, Zhendong Xie⁵

Affiliations

¹ Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan 250061, PR China. Electronic address: zhulihuasdu@163.com.
² Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan 250061, PR China. Electronic address: guan_yanjin@sdu.edu.cn.
³ Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan 250061, PR China. Electronic address: linjun@sdu.edu.cn.
⁴ Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan 250061, PR China. Electronic address: zjq@sdu.edu.cn.
⁵ Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan 250061, PR China. Electronic address: xiezhendong1989@163.com.

PMID: 29908608
DOI: 10.1016/j.ultsonch.2018.04.017

Abstract

A nanocrystalline-amorphous (NC-A) mixed layer was obtained by ultrasonic shot peening (USP) on pure titanium at room temperature and observed by X-ray diffraction pattern (XRD), scanning electron microscope (SEM) and high-resolution transmission electron microscope (HRTEM). The results showed that the amorphization percentage in the NC-A mixed layer increased continuously with the increase of the peening duration, shot diameter and sonotrode amplitude or the decrease of the peening distance. The maximum amorphization percentage achieved in this study was 44.09%. Moreover, with the amorphization percentage in the NC-A mixed layer increasing, the surface hardness increased constantly. Base on the experimental results, the amorphization mechanism during USP treatment was also analyzed.

Keywords: Nanocrystalline-amorphous mixed layer; Pure titanium; Surface hardness; Surface partial amorphization; Ultrasonic shot peening.