Microstructural factors determining mechanical properties of laser-welded Ti-4.5Al-2.5Cr-1.2Fe-0.1C alloy for use in next-generation aircraft

Masaaki Nakai, Mitsuo Niinomi, Toshikazu Akahori, Kazuhiro Hayashi, Yoshio Itsumi, Shogo Murakami, Hideto Oyama, Wataru Abe

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)

Abstract

The complex microstructure of a high hot-workable α + β-type titanium alloy, Ti-4.5Al-2.5Cr-1.2Fe-0.1C with a continuously varying α phase in terms of its size, distribution, morphology, and crystal orientation from the welded zone to the matrix, including a trace amount of welding defect, was investigated by several microstructural and crystallographical analysis techniques such as optical microscopy, scanning electron microscopy, and X-ray diffraction to elucidate the crucial factors determining its mechanical properties such as tensile properties and fatigue etc. The alloy was processed with laser welding to prepare parts for use in next-generation aircraft. The tensile properties of welded samples exhibit a strength-ductility balance similar to that of non-welded sample. All the failures in these samples occur at their matrices because the hardness values of welded zone on the cross section perpendicular to loading direction of the welded samples are higher than that on the same plane of non-welded sample, which is related to crystal texture of α phase. However, the fatigue strengths of welded samples are lower than that of non-welded sample. Such the decrease in fatigue strength of welded samples is caused by the presence of pores formed during welding.

Original languageEnglish
Pages (from-to)55-65
Number of pages11
JournalMaterials Science and Engineering A
Volume550
DOIs
Publication statusPublished - 2012 Jul 30

Keywords

  • Anisotropy
  • Fatigue
  • Laser welding
  • Mechanical properties
  • α+β-type titanium alloy

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Fingerprint Dive into the research topics of 'Microstructural factors determining mechanical properties of laser-welded Ti-4.5Al-2.5Cr-1.2Fe-0.1C alloy for use in next-generation aircraft'. Together they form a unique fingerprint.

Cite this