Crack initiation mechanisms in Ti-6Al-4V subjected to cold dwell-fatigue, low-cycle fatigue and high-cycle fatigue loadings

被引:38
作者
Lavogiez, C. [1 ]
Dureau, C. [1 ,2 ,3 ]
Nadot, Y. [1 ]
Villechaise, P. [1 ]
Hemery, S. [1 ]
机构
[1] Univ Poitiers, Inst Pprime, CNRS UPR 3346, ISAE ENSMA, Teleport 2,1 Ave Clement Ader,BP 40109, F-86961 Futuroscope, France
[2] Univ Lorraine, Lab Etud Microstruct & Mecan Mat, CNRS UMR 7239, 7 Rue Felix Savart, F-57070 Metz, France
[3] Univ Lorraine, LAb EXcellence Design Alliages Metall Allegement, 7 Rue Felix Savart, F-57070 Metz, France
关键词
Titanium alloys; Low cycle fatigue; High cycle fatigue; Dwell-fatigue; Microstructure; CRYSTALLOGRAPHIC ORIENTATION; SENSITIVE FATIGUE; TITANIUM-ALLOY; ALPHA-TITANIUM; MICROSTRUCTURE; TEXTURE; DEFORMATION; PROPAGATION; VARIABILITY; MORPHOLOGY;
D O I
10.1016/j.actamat.2022.118560
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
Although Ti-6Al-4V is the most commonly used titanium alloy in the aerospace industry, the mechanisms gov-erning crack initiation in the different fatigue regimes are not well understood yet. This situation partly pertains to a competition between multiple crack initiation mechanisms. In particular, applied loading conditions were identified as a key parameter governing the transition between mechanisms. The fatigue behavior of Ti-6Al-4V with a bi-modal microstructure was investigated in the present study using different waveforms, load ratios and frequencies to clarify this feature. A detailed characterization of the main crack initiation sites was carried out to identify microstructural configurations governing crack nucleation in low-cycle dwell-fatigue, low-cycle fatigue and high-cycle fatigue regimes. While lifetimes and fracture surfaces showed a good consistency with data from prior studies, a single microstructural configuration was found involved with the formation of crack initiation facets. All investigated cracks leading to specimen failure were nucleated along (0001) twist grain boundaries exhibiting similar features. Based on this finding, a criterion is proposed to identify candidates for crack initi-ation. This also demonstrates no major sensitivity of the critical microstructural configurations to environment, free surface, loading conditions and, as shown in previous studies, microstructure and composition. However, conventional fatigue failure results from one, or a few, surface or subsurface crack initiation sites while dwell-fatigue failure involves the formation of multiple internal cracks. This is accompanied by a significant dwell-fatigue life debit at peak stress magnitudes close to the yield strength. Features of microstructural configura-tions prone to crack nucleation are finally compared with data reported in existing literature to propose a mechanism of crack formation in Ti alloys.
引用
收藏
页数:15
相关论文
共 57 条
[1]  
[Anonymous], 2022, ROLE CRYSTALLOGRAPHI
[2]  
Bache M. R., 1997, International Journal of Fatigue, V19, pS83, DOI 10.1016/S0142-1123(97)00020-0
[3]   Microstructural Control of Fatigue Behaviour in a Novel α plus β Titanium Alloy [J].
Bache, Martin ;
Davies, Helen ;
Davey, William ;
Thomas, Matthew ;
Berment-Parr, Iain .
METALS, 2019, 9 (11)
[4]   A review of dwell sensitive fatigue in titanium alloys: the role of microstructure, texture and operating conditions [J].
Bache, MR .
INTERNATIONAL JOURNAL OF FATIGUE, 2003, 25 (9-11) :1079-1087
[5]   The effect of grain orientation on fracture morphology during high-cycle fatigue of Ti-6Al-4V [J].
Bantounas, Ioannis ;
Dye, David ;
Lindley, Trevor C. .
ACTA MATERIALIA, 2009, 57 (12) :3584-3595
[6]  
Beausir B., 2017, ANAL TOOLS ELECT XRA
[7]   Slip and fatigue crack formation processes in an α/β titanium alloy in relation to crystallographic texture on different scales [J].
Bridier, F. ;
Villechaise, P. ;
Mendez, J. .
ACTA MATERIALIA, 2008, 56 (15) :3951-3962
[8]   Effect of macrozones on fatigue crack initiation and propagation mechanisms in a forged ti-6Al-4V alloy under fully-reversed condition [J].
Briffod, Fabien ;
Shiraiwa, Takayuki ;
Enoki, Manabu ;
Emura, Satoshi .
MATERIALIA, 2022, 22
[9]   Effect of crystallographic orientation and geometrical compatibility on fatigue crack initiation and propagation in rolled Ti-6Al-4V alloy [J].
Briffod, Fabien ;
Bleuset, Alexandre ;
Shiraiwa, Takayuki ;
Enoki, Manabu .
ACTA MATERIALIA, 2019, 177 :56-67
[10]   Factors determining room temperature mechanical properties of bimodal microstructures in Ti-6Al-4V alloy [J].
Chong, Yan ;
Bhattacharjee, Tilak ;
Park, Myeong-Heom ;
Shibata, Akinobu ;
Tsuji, Nobuhiro .
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, 2018, 730 :217-222