New Microstrueture Design for Commercially Pure Titanium with Outstanding Mechanical Properties by Mechanical Milling and Hot Roll Sintering

摘要

Commercially pure titanium powder is subjected to mechanical milling (MM)-a severe plastic deformation process-for various periods of time. The MM powder has two different kinds of microstrueture, which can be controlled by the MM conditions. They include ultra fine and coarse grain structures known as "shell" and "core", respectively. Subsequently, these MM powder is sintered using a hot roll sintering (HRS) process. The HRS materials with the shell and the core have a network structure of continuously connected shells, which is known as a harmonic structure. The HRS materials with the harmonic structure simultaneously demonstrate both high strength and elongation. These outstanding mechanical properties are influenced by the harmonic structure characteristics such as shell and core grain sizes, and shell fraction and shell network size. Thus, the harmonic structure can be considered as a remarkable design for improving the mechanical properties of commercially pure titanium as well as other metallic materials.