scholarly journals Evaluation of Low Cycle Fatigue Performance of Selective Laser Melted Titanium Alloy Ti–6Al–4V

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1041 ◽  
Author(s):  
Peng Zhang ◽  
Allen Naihui He ◽  
Fei Liu ◽  
Kaifei Zhang ◽  
Junjie Jiang ◽  
...  
Keyword(s):  
Low Cycle Fatigue ◽  
Fatigue Cracks ◽  
Cyclic Stress ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Low Carbon ◽  
Specific Strength ◽  
Material Fatigue ◽  
Lower Strain ◽  
High Degree

The material of Ti–6Al–4V has been widely applied in various industries, such as automobile, aerospace, and medical due to its high specific strength, superior thermal stability and strong corrosion resistance. In the recent decades, selective laser melting (SLM) has become an attractive method to fabricate Ti–6Al–4V parts, thanks to its significant advantages in low material consumption, the high degree of freedom in design, low carbon footprint, etc. Predictability of SLM material fatigue properties is especially important for the safety-critical structures under dynamic load cases. The present research is aimed at evaluating the low cycle fatigue (LCF) performance of SLM Ti–6Al–4V under high loading states. LCF tests were performed for as-built and annealed SLM Ti–6Al–4V. Comparison between LCF properties of SLM Ti–6Al–4V and the wrought Ti–6Al–4V was also made. It was found that as-built SLM Ti–6Al–4V demonstrated a comparable LCF performance with the wrought material. The LCF life of as-built SLM Ti–6Al–4V was longer than that of wrought Ti–6Al–4V at lower strain amplitudes. However, the wrought Ti–6Al–4V had better LCF performance at higher strain amplitudes. The results revealed that the porosity in the as-built SLM material exerted much more impact on the degradation of the material at high strain amplitudes. Annealing deteriorated the LCF performance of SLM Ti–6Al–4V material due to the formation of coarser grains. The cyclic Ramberg–Osgood and the Basquin–Coffin–Manson models were fitted to depict the cyclic stress–strain and the strain–life curves for the SLM Ti–6Al–4V, based on which the LCF performance parameters were determined. In addition, the fatigue fracture surfaces were observed by using scanning electron microscopy (SEM), and the results indicated that fatigue cracks originated from the surface or subsurface defects.

Low Cycle Fatigue of Cast γ-TiAl Based Alloys at High Temperature

2010 ◽  
Vol 452-453 ◽  
pp. 421-424 ◽  
Author(s):  
Martin Petrenec ◽  
Miroslav Šmíd ◽  
Tomáš Kruml ◽  
Karel Obrtlík ◽  
Jaroslav Polák
Keyword(s):  
Fatigue Life ◽  
Low Cycle Fatigue ◽  
Fatigue Cracks ◽  
Surface Region ◽  
Cyclic Stress ◽  
Cyclic Strength ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Nb Content ◽  
Cyclic Straining

The low-cycle fatigue properties of cast nearly lamellar TiAl alloys with diverse Nb content at room temperature and 750°C were compared. Monotonic tensile curves, cyclic stress-strain curves (CSSC) and combined fatigue life curves were obtained at both temperatures. After cyclic straining the surface relief and the fracture surfaces were observed using scanning electron microscopy. The increase in Nb content significantly improves tensile properties and CSSCs at both temperatures. The combined fatigue life curves especially at 750 °C are shifted to higher fatigue lives. The effect o Nb content on the tensile and cyclic strength is discussed in relation to the thickness of the lamellae. Persistent slip markings formed along interlamellar interfaces were predominant locations for fatigue cracks. At both temperatures and materials showed similar crack initiation and propagation behavior. The cracks initiated at surface or in sub-surface region creating smooth flat areas corresponding to the persistent slip bands.

Effect of Fiber Volume Fraction on Low Cycle Fatigue Behavior of Al2O3f/Al-Si Composites

2012 ◽  
Vol 268-270 ◽  
pp. 87-91
Author(s):  
Jian Jun Cui ◽  
Bing Chao Li ◽  
Guo Hua Zhang ◽  
Jian Xin Zhang ◽  
Zuo Shan Wei ◽  
...  
Keyword(s):  
Volume Fraction ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Fatigue Cracks ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Short Fibers ◽  
Fiber Volume ◽  
Large Size

The tensile and low cycle fatigue tests were carried out on alumina short fibers reinforced Al-Si piston alloy composites (Al-Si MMCs). Three Al-Si MMCs reinforced with 10, 17 and 25 vol.% of alumina short fibers were prepared to investigate the effects of volume fraction on tensile and low cycle fatigue properties at room temperature (RT) and 350°C. The results showed that the tensile strength decreased with the increasing of volume fraction of fibers at RT and was slight different at 350°C. Among the three MMCs, the 17%-MMCs showed highest stress level under the low cycle fatigue tests. The fatigue cracks were usually initiated from the clustered and large size fibers near the surface of specimen, propagated along the fiber/matrix interface at RT and grew rapidly by means of broken the fibers at 350°C.

Effect of Fiber Volume Fraction on Low Cycle Fatigue Behavior of Al2O3f/Al-Si Composites

2012 ◽  
Vol 622-623 ◽  
pp. 1340-1344
Author(s):  
Jian Jun Cui ◽  
Bing Chao Li ◽  
Guo Hua Zhang ◽  
Jian Xin Zhang ◽  
Zuo Shan Wei ◽  
...  
Keyword(s):  
Volume Fraction ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Fatigue Cracks ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Short Fibers ◽  
Fiber Volume ◽  
Large Size

The tensile and low cycle fatigue tests were carried out on alumina short fibers reinforced Al-Si piston alloy composites (Al-Si MMCs). Three Al-Si MMCs reinforced with 10, 17 and 25 vol.% of alumina short fibers were prepared to investigate the effects of volume fraction on tensile and low cycle fatigue properties at room temperature (RT) and 350°C. The results showed that the tensile strength decreased with the increasing of volume fraction of fibers at RT and was slight different at 350°C. Among the three MMCs, the 17%-MMCs showed highest stress level under the low cycle fatigue tests. The fatigue cracks were usually initiated from the clustered and large size fibers near the surface of specimen, propagated along the fiber/matrix interface at RT and grew rapidly by means of broken the fibers at 350°C.

Cyclic Behavior of Class U Wheel Steel

1981 ◽  
Vol 103 (1) ◽  
pp. 113-118 ◽  
Author(s):  
Y. J. Park ◽  
D. H. Stone
Keyword(s):  
Low Cycle Fatigue ◽  
Cyclic Softening ◽  
Fatigue Tests ◽  
Wheel Steel ◽  
Cyclic Behavior ◽  
Fatigue Properties ◽  
Test Results ◽  
Cycle Fatigue ◽  
Lower Strain ◽  
Service Environments

In order to evaluate the material properties of Class U wheel steel under cyclic loading, low-cycle fatigue tests were conducted at room temperature on specimens taken from the rim of the wheel. The test results show that Class U wheel steel experiences significant cyclic softening at lower strains, but cyclically hardens at larger strain levels. Due to the cyclic softening at lower strain levels, the steel will plastically deform, even at stresses of about one-half of the monotonic yield strength. Quantitative fatigue properties, which can then be used to predict accurate fatigue lives of various components of wheels under complex service environments, are also obtained from the low-cycle fatigue tests.

High Strain Low Cycle Fatigue and Anti-Seismic Behavior of HRB400 QST Reinforced Steel Bars

2011 ◽  
Vol 250-253 ◽  
pp. 1128-1133 ◽  
Author(s):  
Yu Kun Lv ◽  
Guang Min Sheng ◽  
Hao Fei Xue
Keyword(s):  
High Strain ◽  
Low Cycle Fatigue ◽  
Hardened Layer ◽  
Cyclic Stress ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Steel Bars ◽  
Reinforced Steel ◽  
Surface Scan ◽  
The Relationship

Based on the failure model of building structural steels under earthquake loading, High strain low cycle fatigue properties of HRB400QST (yield strength grade 400MPa, Quenched and Self Tempered) reinforced steel bars with diameters of 20mm and 16mm(unmachined) and HRB400V-N MA(microalloying)with diameters of 16mm (unmachined) were investigated. Based on the tests of total strain controlling, cycle strain response character of three kinds of steel bars and the relationship between cyclic stress and strain were researched. Hollomon and Coffin-Manson formulas were used to induce fatigue life formulas of three kinds of steel bars, and then the values of σa·Δεt were gained when Nf =100, calculated results show that the high strain low cycle fatigue properties of HRB400V-N MA rebars tested are much better than HRB400QST steel bars. Rupture surface scan reveals that surface hardened layer will reduce the cyclic toughness, and is bad for the anti-seismic performance.

High-Temperature Low-Cycle Fatigue Behavior of 625 Nickel-Base Superalloy Welding Joint

2014 ◽  
Vol 618 ◽  
pp. 120-124
Author(s):  
Yuan Yuan Wang ◽  
Bao Sen Wang ◽  
Li Jia Chen
Keyword(s):  
High Temperature ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Fatigue Cracks ◽  
Fatigue Properties ◽  
Nickel Base Superalloy ◽  
Cycle Fatigue ◽  
Welding Joint ◽  
Nickel Base ◽  
Base Superalloy

High temperature low cycle fatigue properties and fracture behavior of Inconel 625 nickel-base superalloy welding joint at 760oC were investigated under fully reversed total strain-controlled mode. The fatigue life and cyclic stress-strain data were analyzed to determine the individual strain fatigue parameters. It is noted that the welding joint exhibits the cyclic strain hardening and stability. The fatigue cracks initiate predominantly on the free surface of fatigue specimens and propagate in an intergranular mode or a mixed transgranular and intergranular mode.

Effect of T6 Treatment on Low-Cycle Fatigue Properties of Al-6Zn-2.5Mg-2Cu-0.1Zr-0.1Sc Alloy

2014 ◽  
Vol 664 ◽  
pp. 28-33
Author(s):  
Ying Lan ◽  
Li Jia Chen ◽  
Xin Che ◽  
Feng Li
Keyword(s):  
Strain Hardening ◽  
Low Cycle Fatigue ◽  
Aging Treatment ◽  
Cyclic Strain ◽  
Cyclic Stress ◽  
Cyclic Strength ◽  
Fatigue Properties ◽  
Strain Hardening Exponent ◽  
Cycle Fatigue ◽  
Linear Behavior

The low-cycle fatigue behaviors of as-extruded and T6 treated Al-6Zn-2.5Mg-2Cu-0.1Zr-0.1Sc alloys at room temperature have been investigated under those total-strain amplitudes ranged from 0.3% to 1.0%, and the influence of T6 treatment on the low-cycle fatigue properties of Al-6Zn-2.5Mg-2Cu-0.1Zr-0.1Sc alloy was clarified. The experimental results show that during fatigue deformation, the significant cyclic strain hardening and stable cyclic stress response can be noted for both as-extruded and T6 treated Al-6Zn-2.5Mg-2Cu-0.1Zr-0.1Sc alloys. The fatigue life of as-extruded Al-6Zn-2.5Mg-2Cu-0.1Zr-0.1Sc alloy at all strain amplitudes is longer than that of the alloy subjected to T6 aging treatment. The relationship between both elastic and plastic strain amplitudes with reversals to failure shows a monotonic linear behavior, and can be described by the Basquin and Coffin-Manson equations, respectively. The T6 treatment can significantly increase the cyclic strain hardening exponent and cyclic strength coefficient of extruded Al-6Zn-2.5Mg-2Cu-0.1Zr-0.1Sc alloy.

Fatigue Properties of 316L Stainless Steel

2012 ◽  
Vol 204-208 ◽  
pp. 3786-3789
Author(s):  
Xiao Zhao
Keyword(s):  
Stainless Steel ◽  
Room Temperature ◽  
316L Stainless Steel ◽  
Low Cycle Fatigue ◽  
Fatigue Cracks ◽  
Testing Machine ◽  
Experimental Studies ◽  
Hydraulic Testing ◽  
Fatigue Properties ◽  
Cycle Fatigue

The present paper deals with experimental studies on the tension-tension fatigue properties of 316L stainless steel by using a servo-valve controlled electro-hydraulic testing machine at room temperature. The low cycle fatigue properties of 316L stainless steel were studied and the initiation mechanisms of fatigue cracks were investigated and analyzed with scanning electron microscopy (SEM). Preliminary results indicate that the S-N curve of 316L stainless steel descends linearly in the low cycle regime and fatigue failure initiates from inclusions/defects on the specimen surface.

Sign in / Sign up

Export Citation Format

Share Document