Effect of microstructure and relaxation behavior on the high temperature low cycle fatigue of near-α-Ti-1100

Lee, Duck Hee; Nam, Soo Woo; Choe, Seung Joo

doi:10.1016/s0921-5093(00)00974-6

Cited by 14 publications

(8 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, during the second stage of stress relaxation, the relaxation is caused by dislocation glide under high stress, which occurs at a lower rate. That explains the low rate of stress relaxation during the second stage [16][17][18].…”

Section: Discussionmentioning

confidence: 96%

Stress Relaxation Properties and Microscopic Deformation Structure in Bending of the C7025 and C7035 Alloy

Xiao

Huang

et al. 2018

Crystals

View full text Add to dashboard Cite

Stress relaxation tests in cantilever bending were performed on the C7025 and C7035 alloys at 298 K and 393 K, respectively. The effect of stress-relief treatments on stress relaxation properties was investigated. The structural changes associated with the stress relaxation process were examined using transmission electron microscopy. The stress relaxation curve fits well to empirical formula σ* = [K'ln(t + α 0 ) + C] −n for stress relaxation. The curves can be split into two stages. The stress drops fast at first and then it gets slower in the second stage, and tends towards a certain limited value after a long time. The curve and microstructure reveal that the C7035 alloy has a lower rate of stress relaxation and a higher anti-stress relaxation capacity than the C7025. The first reason is that the movement of vacancies required by spinodal decomposition is inhibited, and the quantity of cobalt-containing vacancies decreases dramatically in the C7035 alloy. The other reason is that the precipitated phases became uniformly diffused in the C7035 alloy. The precipitate phase is uniformly distributed in the grain boundaries and the matrix, during the relaxed condition, and thus the dislocation movement is blocked by the precipitate.Crystals 2018, 8, 324 2 of 10 room temperature, and considered that the recovery and relaxation process was similar, which results in dislocation migration, dislocation rearrangement, and dislocation annihilation. The stress relaxation behavior of beryllium copper was studied by Li Yilian [10]. Due to the effect of elastic stress, beryllium atomic uphill diffusion occurs, Guinier Preston zone (G.P.) areas are formed, thus improving the stress relaxation and stabilty performance of the alloy at room temperature. It is important to characterize the stress relaxation behavior of elastic copper alloy not only in terms of the remaining stress after exposure to elevated temperatures, but also in terms of microstructural changes. The purpose of this paper is to present the results of low temperature stress relaxation tests performed with C7025 and C7035 alloys and attempt to ascertain the mechanism of microscopic deformation. Experimental SectionThe materials selected for this study were C7025 and C7035 alloys in the form of plates with a thickness of 0.3 mm in a cold-rolled condition. The chemical composition of the alloys is shown in Table 1. Stress relaxation testing was carried out according to ASTM E328-2002(2008) standard method for plate products. The specimens for stress relaxation (Figure 1) were cut parallel to the rolling direction of the plate, using spark machinery from stock samples. A machine or system for special use has been developed to conduct the stress relaxation tests for plate ( Figure 2). The configuration of the system is described in Reference [11] in detail. The stress relaxation was performed in a furnace at the test temperature. The temperature was monitored by a thermocouple placed in the grips near the specimen and the temperature was controlled to within ±1 K du...

show abstract

Section: Discussionmentioning

confidence: 96%

Stress Relaxation Properties and Microscopic Deformation Structure in Bending of the C7025 and C7035 Alloy

Xiao

Huang

et al. 2018

Crystals

View full text Add to dashboard Cite

show abstract

“…During occurs at a lower rate. That explains the low rate of stress relaxation during the second stage [13][14][15].…”

Section: Discussionmentioning

confidence: 96%

Stress Relaxation Properties and Microscopic Deformation Structure in Bending of the C7025 and C7035 Alloy

Xiao¹,

Xu²,

Huang³

et al. 2018

Preprint

View full text Add to dashboard Cite

Stress relaxation tests in cantilever bending were performed on the C7025 and C7035 alloys at 298K and 393K，respectively. The effect of stress-relief treatments on stress relaxation properties was investigated. The structural changes associated with the stress relaxation process were examined using transmission electron microscope. The stress relaxation curve fits well to empirical formula σ*=[Kˊln(t+α0)+C]-n for stress relaxation. The curves can be split into two stages. The stress relax quickly in the first stage, slows down in the second stage, and tends to be a certain limit value after a long time. The curve and microstructure reveals that the C7035 alloy has a lower rate of stress relaxation and a higher anti-stress relaxation capacity than the C7025. The first reason is that the movement of vacancies required by spinodal decomposition is inhibited, and the quantity of cobalt -containing vacancies decreases dramatically in the C7035 alloy. The other reason is that the precipitated phases became uniformly diffused in the C7035 alloy. The precipitate phase uniformly distributes in the grain boundaries and the matrix, during the relaxed condition, and thus the dislocations moving is blocked by the precipitates.

show abstract

“…The strength of Ti-2Fe-0.1B alloy after heat treatment is lower than that of the as-rolled, which is dependent on the microstructure and phase content obtained by heat treatment. As can be seen from Fig.4, during the tensile test, the equiaxed microstructure has a relatively obvious necking phenomenon, which is caused by the deformation coordination of equiaxed primary α phase in the equiaxed microstructure [13,14] . The lamellar microstructure enters the yielding stage prematurely because the large α-colony can reduce the strength of the lamellar layer.…”

Section: Tensile Propertiesmentioning

confidence: 99%

Study on Microstructure and Mechanical Properties of Low Cost Ti-Fe-B Alloy

Sun

Chang

Fang³

et al. 2020

MATEC Web Conf.

View full text Add to dashboard Cite

Microstructure evolution and mechanical properties of low cost Ti-2Fe-0.1B alloy under different heat treatment were studied. Results indicated that two kinds of equiaxed microstructures with different characteristics were obtained in conventional and double annealing, and typical lamellar microstructure was obtained in β annealing. Tensile test results shown that as-received rolled alloy possess highest strength and plasticity simultaneously due to fine and entangled microstructure. Uniform equiaxed dimples were observed in microstructure, which revealed ductile fracture morphology. Key words: titanium alloy; microstructure; heat treatment; mechanical properties

show abstract

Effect of microstructure and relaxation behavior on the high temperature low cycle fatigue of near-α-Ti-1100

Cited by 14 publications

References 13 publications

Stress Relaxation Properties and Microscopic Deformation Structure in Bending of the C7025 and C7035 Alloy

Stress Relaxation Properties and Microscopic Deformation Structure in Bending of the C7025 and C7035 Alloy

Stress Relaxation Properties and Microscopic Deformation Structure in Bending of the C7025 and C7035 Alloy

Study on Microstructure and Mechanical Properties of Low Cost Ti-Fe-B Alloy

Contact Info

Product

Resources

About