Microbehavior Analysis of Ti Nanowires in [0001]/[-12-10] direction and Nanoplates in [-12-10] direction under uniaxial stretching by Molecular Dynamics Simulation

• Main Authors: ZHENG JING REN, 鄭景仁
• Other Authors: Yuan-Ching Lin
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/65067471966259116012

碩士 === 國立臺灣科技大學 === 機械工程系 === 103 === The main purpose of this paper is using the molecular dynamics to investigate titanium nanowires in [-12-10] and [0001] direction, and titanium nanoplates in [-12-10] direction of stretch in different strain rates, sheet thickness and other conditions to explore its yield mechanism, the flow stress and the breaking mode. Simulation results show, when the nanowires and nanoplates of stretch in different strain rates, its yield stress and Young's modulus do not change significantly. When titanium nanowires of stretch yields in [0001] direction, the transition would happened with the HCP crystals from [0001] to [10-10] stretch direction, and it is possible to causes FCC crystals formation in the transition. When titanium nanowires of stretch yields in [-12-10] direction, it will use pyramidal plane system to slip. Titanium nanowires in these two directions would use pyramidal plane system to slip and decomposed into two partial dislocations and cause the FCC stacking fault formation. FCC stacking fault will expand gradually as the stretching process. When it reaches a certain number of FCC stacking fault, the partial dislocations would slip again in FCC stacking fault with FCC {111} planes. With the partial dislocations continues slip in FCC stacking fault, it would finally cause the nanowires breaking. The nanoplates of stretch yields in [-12-10] also use pyramidal plane system to slip. Finally the nanoplates use dislocations slip from nanoplates surface and cause it breaking.