Effect of Nitrogen Ion Implantation on the Elavated Temperature Fatigue of Shot-peened Titanium Alloy

Abstract

This study focuses on the influence of nitrogen ion implantation (NII) on the medium-temperature fatigue performance of SP layer. The mean fatigue life of the SP TA15 titanium alloy was increased 27.5 times, furthermore, the median fatigue life of the-NII treated specimen at 500 ◦C for 5 h was increased by a factor of 17, compared with as-received. The SP process produced high-density dislocations and grain refinements in primary the α-phase grains. After heat exposure at 500 ◦C/5h, dislocations and other substructures became reduced and the grains were coarsened. Furthermore, after NII treatment, the same at 500 ◦C for 5 h, a large number of TiN phases were generated so that the high-density dislocations were retained