Evolution of lattice strain in Ti–6Al–4V during tensile loading at room temperature

Stapleton, Adam M.; Raghunathan, S.L.; Bantounas, Ioannis; Stone, H.J.; Lindley, T.C.; Dye, David

doi:10.1016/j.actamat.2008.08.030

Cited by 98 publications

(71 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This finding is also at variance with the results of Liu et al 19 who used a fixed tool rotational speed of 400 rev min 21 and feedrates between 25 and 100 mm min 21 and observed steadily increasing tensile strength as feedrate increased. Joint efficiencies in the present work are higher than the peak value (0?90) reported in Ref.…”

Section: Tensile Testingcontrasting

confidence: 74%

Residual stresses, microstructure and tensile properties in Ti–6Al–4V friction stir welds

Steuwer

Hattingh

James

et al. 2012

Science and Technology of Welding and Joining

View full text Add to dashboard Cite

This paper reports the results of a systematic investigation of residual stresses as a function of welding speed in a set of Ti-6Al-4V friction stir welds. The investigation focuses on residual stress but links these data with microstructural information derived from micrographs and hardness measurements as well as mechanical testing results. Residual stresses were determined using energy dispersive synchrotron X-ray diffraction, which allows phase specific stresses to be distinguished. The data presented in this paper demonstrate that welds with high tensile properties can be obtained, which also have relatively low peak tensile residual stress values of y30% of the tensile strength. The data also show a clear correlation between heat input and the width of the residual stress profile. IntroductionTi-6Al-4V is an alpha-beta titanium alloy that offers a good combination of low density, high strength and excellent corrosion resistance, and has high biocompatibility. It is widely used in the aerospace sector, in high performance automotive parts, in chemical industries and in the manufacture of implantable medical devices and sensors, and accounts for more than 50% of all titanium alloy usage.While fusion welding techniques can be readily applied to Ti-6Al-4V alloys, their relatively poor thermal conductivity can cause problems through the effects of a high thermal gradient on residual stress, distortion and microstructural modification. Titanium alloys are also sensitive to the presence during welding of contaminants such as hydrogen, oxygen, iron, nitrogen and carbon, which can lead to porosity and hard inclusions. 1 Some difficulties are avoided by welding under inert gas shielded conditions and appropriate measures to avoid cross-contamination from steel manufacturing processes, e.g. a dedicated clean area for titanium.The development of solid state welding processes, such as friction stir welding (FSW), which are performed at reduced peak temperatures, offers the potential to reduce distortion and achieve lower residual stress values. Solid state stirring processes with their associated recrystallisation also lead to generally favourable microstructural modification, e.g. fine equiaxed grains in the weld nugget. The advantages of friction welding processes, in terms of weld preparation and post-weld dressing, microstructure and mechanical performance, have therefore led to significant interest in their application to certain high technology industrial sectors, e.g. transportation. [2][3][4][5] The focus of the present paper is to identify process parameters that give good tensile properties relative to parent plate values along with low levels of residual stress and hence which would give good static and dynamic performance in service. To this end, FS butt welds were made in 3 mm Ti-6Al-4V plate at five different tool travel speeds, ranging from 45 to 165 mm min 21 with a constant tool rotational speed of 550 rev min 21 , and the residual stresses were investigated non-destructively using synchrotron X-ray dif...

show abstract

Section: Tensile Testingcontrasting

confidence: 74%

Residual stresses, microstructure and tensile properties in Ti–6Al–4V friction stir welds

Steuwer

Hattingh

James

et al. 2012

Science and Technology of Welding and Joining

View full text Add to dashboard Cite

show abstract

“…[27,28] Full Debye-Scherrer diffraction rings were collected from the monochromated X-ray beam (300 9 300 lm, k = 0.14291 Å ) every 2 seconds by a Pixium 4700 2D area detector. Thermal cycling was achieved by resistance heating using an Instron electrothermal mechanical tester (ETMT), [29,30] controlled by an R-type thermocouple, spot welded to the sample directly above the X-ray beam. The heating and cooling rate used throughout the experiment was~1°C s À1 from room temperature to 140°C for TiNi and to 85°C for TiNiCu.…”

Section: Methodsmentioning

confidence: 99%

In-Situ Synchrotron Characterization of Transformation Sequences in TiNi-Based Shape Memory Alloys during Thermal Cycling

Jones

Raghunathan

Dye

2010

Metall Mater Trans A

View full text Add to dashboard Cite

In-situ synchrotron radiation has been used to provide direct analysis of the transformation sequences in TiNi-based shape memory alloys during thermal cycling. The high resolution, narrow peak width Debye-Scherrer diffraction spectra enabled positive identification and quantification of the phase transformation sequences, which is not possible through normal laboratory studies. The results facilitate a clearer understanding of the development and influence of intermediate phases such as R or B19 on sequential martensitic transformations. Ti 50.2 Ni 49.8 transformed predominately via a single-step B2 M B19¢ transformation, although evidence of the R phase was found during cooling in every cycle. The martensitic start temperature was depressed by~0.6°C per cycle, while the R-phase start temperature was found to be unaffected. Ti 50 Ni 41 Cu 9 transformed through a two-step B2 M B19 M B19¢ sequence, with the B2 fi B19 transformation reaching completion prior to the formation of any B19¢. The transformation temperatures of Ti 50 Ni 41 Cu 9 were found to be insensitive to thermal cycling, remaining constant over the studied cycle range.

show abstract

“…Therefore, the interaction between particles in the matrix phase and the surrounding has been simulated quantitatively for TC4, which means that the load distribution in the matrix phase is more complicated than that in the inclusion phase. Table 4 shows the values of the crystal plane diffraction elastic constant of matrix phase E M hkl , and the inclusion phase E C hkl , respectively, compared with those reported in the literature [43]. In Equation 30, the mechanical elastic modulus of α-Ti is clearly different from the diffraction elastic modulus related to the crystal plane orientation.…”

Section: Calculation Results and Validationmentioning

confidence: 98%

Mesomechanical Modeling and Numerical Simulation of the Diffraction Elastic Constants for Ti6Al4V Polycrystalline Alloy

Chen

Liu

Zhu

et al. 2018

Metals

View full text Add to dashboard Cite

A mesoscopic mechanical model based on the Mori-Tanaka method and Eshelby’s inclusion theory was presented to investigate the uniform elastic deformation behavior of Ti6Al4V with β-Ti and α-Ti phases. In particular, elastic mechanics field equations of inclusion and matrix phases were established separately, and several crystal plane diffraction elastic constants were predicted under uniaxial loading in this model. The results demonstrated that diffracted crystal plane elastic constants diversified with the elastic stiffness of the composition phase. In consequence, elastic deformation of one particular phase is related to the constraint of the whole deformation of all the phases constituting the materials. In this work, diffracted crystal plane elastic constants corresponding to different phases exert a substantial role in the determination of stresses by diffraction methods. Several numerical simulation results were compared and discussed.

show abstract

Evolution of lattice strain in Ti–6Al–4V during tensile loading at room temperature

Cited by 98 publications

References 25 publications

Residual stresses, microstructure and tensile properties in Ti–6Al–4V friction stir welds

Residual stresses, microstructure and tensile properties in Ti–6Al–4V friction stir welds

In-Situ Synchrotron Characterization of Transformation Sequences in TiNi-Based Shape Memory Alloys during Thermal Cycling

Mesomechanical Modeling and Numerical Simulation of the Diffraction Elastic Constants for Ti6Al4V Polycrystalline Alloy

Contact Info

Product

Resources

About