Fatigue Testing of Titanium Alloy Ti6Al4V Used in Medical Devices

Because titanium alloy Ti6Al4V features low density, good corrosion resistance and biocompatibility, it a metal of choice for medicine, used in orthopedics, accident surgery and dentistry. The insertion of elements such as nitrogen, carbon, hydrogen, iron or oxygen improve fatigue strength of this material. This paper presents certain basic fatigue and monotonic tests performed on the alloy. We have proposed a unique sample geometry and sample dimensions smaller than the reference ones. The dimensions of the working part of the sample correspond to the geometry of a dental implant connector. This part of the implant has to withstand stresses that are both intricate and variable in time. We performed monotonic tensile strength tests and uniaxial fatigue tests using the Instron 8874 machine. Then, we examined the samples under a stereoscopic microscope and measured the fracture development angle.

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Fatigue Characteristics of Selected Light Metal Alloys

Archives of Metallurgy and Materials ◽

10.1515/amm-2016-0051 ◽

2016 ◽

Vol 61 (1) ◽

pp. 271-274 ◽

Cited By ~ 3

Author(s):

M. Cieśla ◽

G. Junak ◽

A. Marek

Keyword(s):

Titanium Alloy ◽

Fatigue Life ◽

High Cycle Fatigue ◽

Fatigue Testing ◽

Low Cycle Fatigue ◽

Light Metal ◽

Fatigue Tests ◽

The Other ◽

Metal Alloys ◽

Cycle Fatigue

The paper addresses results of fatigue testing of light metal alloys used in the automotive as well as aerospace and aviation industries, among others. The material subject to testing comprised hot-worked rods made of the AZ31 alloy, the Ti-6Al-4V two-phase titanium alloy and the 2017A (T451) aluminium alloy. Both low- and high-cycle fatigue tests were conducted at room temperature on the cycle asymmetry ratio of R=-1. The low-cycle fatigue tests were performed using the MTS-810 machine on two levels of total strain, i.e.Δεc= 1.0% and 1.2%. The high-cycle fatigue tests, on the other hand, were performed using a machine from VEB Werkstoffprufmaschinen-Leipzig under conditions of rotary bending. Based on the results thus obtained, one could develop fatigue life characteristics of the materials examined (expressed as the number of cycles until failure of sample Nf) as well as characteristics of cyclic material strain σa=f(N) under the conditions of low-cycle fatigue testing. The Ti-6Al-4V titanium alloy was found to be characterised by the highest value of fatigue life Nf, both in lowand high-cycle tests. The lowest fatigue life, on the other hand, was established for the aluminium alloys examined. Under the high-cycle fatigue tests, the life of the 2017A aluminium and the AZ31 magnesium alloy studied was determined by the value of stress amplitude σa. With the stress exceeding 150 MPa, it was the aluminium alloy which displayed higher fatigue life, whereas the magnesium alloy proved better on lower stress.

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Drilling of titanium alloy (Ti6Al4V) – a review

Machining Science and Technology ◽

10.1080/10910344.2021.1925295 ◽

2021 ◽

pp. 1-66

Author(s):

Chua Guang Yuan ◽

A. Pramanik ◽

A. K. Basak ◽

C. Prakash ◽

S. Shankar

Keyword(s):

Titanium Alloy ◽

Titanium Alloy Ti6al4v

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Fatigue Testing of Wearable Sensing Technologies: Issues and Opportunities

Materials ◽

10.3390/ma14154070 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4070

Author(s):

Andrea Karen Persons ◽

John E. Ball ◽

Charles Freeman ◽

David M. Macias ◽

Chartrisa LaShan Simpson ◽

...

Keyword(s):

Fatigue Life ◽

Prediction Models ◽

Fatigue Testing ◽

Low Cycle Fatigue ◽

Wearable Sensors ◽

Fatigue Tests ◽

Proof Of Concept ◽

Cycle Fatigue ◽

Wearable Sensing ◽

Failure Data

Standards for the fatigue testing of wearable sensing technologies are lacking. The majority of published fatigue tests for wearable sensors are performed on proof-of-concept stretch sensors fabricated from a variety of materials. Due to their flexibility and stretchability, polymers are often used in the fabrication of wearable sensors. Other materials, including textiles, carbon nanotubes, graphene, and conductive metals or inks, may be used in conjunction with polymers to fabricate wearable sensors. Depending on the combination of the materials used, the fatigue behaviors of wearable sensors can vary. Additionally, fatigue testing methodologies for the sensors also vary, with most tests focusing only on the low-cycle fatigue (LCF) regime, and few sensors are cycled until failure or runout are achieved. Fatigue life predictions of wearable sensors are also lacking. These issues make direct comparisons of wearable sensors difficult. To facilitate direct comparisons of wearable sensors and to move proof-of-concept sensors from “bench to bedside,” fatigue testing standards should be established. Further, both high-cycle fatigue (HCF) and failure data are needed to determine the appropriateness in the use, modification, development, and validation of fatigue life prediction models and to further the understanding of how cracks initiate and propagate in wearable sensing technologies.

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Vibration Test of Titanium Alloy Pipes

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.184-185.701 ◽

2012 ◽

Vol 184-185 ◽

pp. 701-706

Author(s):

Ming Xing Qiu ◽

Chuang Shao ◽

Yong Zhou ◽

Li Hua Yue

Keyword(s):

Titanium Alloy ◽

Failure Criteria ◽

Fatigue Tests ◽

Test Method ◽

Displacement Sensor ◽

Laser Displacement Sensor ◽

New Findings ◽

Vibration Fatigue ◽

Welded Pipe ◽

Test Result

In order to determine the fatigue limits of two kinds of titanium alloy pipes connected by welding and rolling, fatigue tests were carried out by the Aero-Criterion which gives vibration fatigue test method and failure criteria. A laser-displacement-sensor was used at the free end and a strain-gauge at the root of the pipe specimen. The test result shows that the fatigue limit of the welded pipe is higher than the rolled one. In the end some new findings are listed according to the test.

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Experimental Design and Validation of an Accelerated Random Vibration Fatigue Testing Methodology

Shock and Vibration ◽

10.1155/2015/147871 ◽

2015 ◽

Vol 2015 ◽

pp. 1-13 ◽

Cited By ~ 7

Author(s):

Yu Jiang ◽

Gun Jin Yun ◽

Li Zhao ◽

Junyong Tao

Keyword(s):

Fatigue Life ◽

Stress Responses ◽

Life Prediction ◽

Random Vibration ◽

Fatigue Testing ◽

Fatigue Tests ◽

Fatigue Life Prediction ◽

Power Spectral ◽

Vibration Fatigue ◽

Non Gaussian

Novel accelerated random vibration fatigue test methodology and strategy are proposed, which can generate a design of the experimental test plan significantly reducing the test time and the sample size. Based on theoretical analysis and fatigue damage model, several groups of random vibration fatigue tests were designed and conducted with the aim of investigating effects of both Gaussian and non-Gaussian random excitation on the vibration fatigue. First, stress responses at a weak point of a notched specimen structure were measured under different base random excitations. According to the measured stress responses, the structural fatigue lives corresponding to the different vibrational excitations were predicted by using the WAFO simulation technique. Second, a couple of destructive vibration fatigue tests were carried out to validate the accuracy of the WAFO fatigue life prediction method. After applying the proposed experimental and numerical simulation methods, various factors that affect the vibration fatigue life of structures were systematically studied, including root mean squares of acceleration, power spectral density, power spectral bandwidth, and kurtosis. The feasibility of WAFO for non-Gaussian vibration fatigue life prediction and the use of non-Gaussian vibration excitation for accelerated fatigue testing were experimentally verified.

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Removal Mechanism of Titanium Alloy Ti6Al4V Based on Single-Grain High Speed Grinding Test

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.487.39 ◽

2011 ◽

Vol 487 ◽

pp. 39-43 ◽

Cited By ~ 1

Author(s):

L. Tian ◽

Yu Can Fu ◽

W.F. Ding ◽

Jiu Hua Xu ◽

H.H. Su

Keyword(s):

Titanium Alloy ◽

High Speed ◽

Chip Thickness ◽

Wheel Speed ◽

High Speed Grinding ◽

Tc4 Alloy ◽

Grinding Mechanism ◽

Single Grain ◽

On Chip ◽

Titanium Alloy Ti6al4v

Single-grain grinding test plays an important part in studying the high speed grinding mechanism of materials. In this paper, a new method and experiment system for high speed grinding test with single CBN grain are presented. In order to study the high speed grinding mechanism of TC4 alloy, the chips and grooves were obtained under different wheel speed and corresponding maximum undeformed chip thickness. Results showed that the effects of wheel speed and chip thickness on chip formation become obvious. The chips were characterized by crack and segment band feature like the cutting segmented chips of titanium alloy Ti6Al4V.

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Gigacycle Fatigue of Welded Joints of Structural Materials (A Review)

Advanced Engineering Forum ◽

10.4028/www.scientific.net/aef.17.14 ◽

2016 ◽

Vol 17 ◽

pp. 14-30 ◽

Cited By ~ 1

Author(s):

Okechukwu P. Nwachukwu ◽

Alexander V. Gridasov ◽

Ekaterina A. Gridasova

Keyword(s):

Fatigue Testing ◽

Fatigue Behavior ◽

Testing Machine ◽

Structural Materials ◽

Fatigue Tests ◽

Material Defects ◽

Graphite Cast Iron ◽

Ultrasonic Fatigue ◽

Materials Used ◽

Fatigue Failures

This review looks into the state of gigacycle fatigue behavior of some structural materials used in engineering works. Particular attention is given to the use of ultrasonic fatigue testing machine (USF-2000) due to its important role in conducting gigacycle fatigue tests. Gigacycle fatigue behavior of most materials used for very long life engineering applications is reviewed.Gigacycle fatigue behavior of magnesium alloys, aluminum alloys, titanium alloys, spheroid graphite cast iron, steels and nickel alloys are reviewed together with the examination of the most common material defects that initiate gigacycle fatigue failures in these materials. In addition, the stage-by-stage fatigue crack developments in the gigacycle regime are reviewed. This review is concluded by suggesting the directions for future works in gigacycle fatigue.

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Analytical modelling of cutting forces in near-orthogonal cutting of titanium alloy Ti6Al4V

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406214542967 ◽

2014 ◽

Vol 229 (6) ◽

pp. 1122-1133 ◽

Cited By ~ 11

Author(s):

Yun Chen ◽

Huaizhong Li ◽

Jun Wang

Keyword(s):

Titanium Alloy ◽

Cutting Forces ◽

Chemical Reactivity ◽

Orthogonal Cutting ◽

Chip Thickness ◽

Analytical Modelling ◽

Shear Instability ◽

Published Data ◽

Machining Processes ◽

Titanium Alloy Ti6al4v

Titanium and its alloys are difficult to machine due to their high chemical reactivity with tool materials and low thermal conductivity. Chip segmentation caused by the thermoplastic instability is always observed in titanium machining processes, which leads to varied cutting forces and chip thickness, etc. This paper presents an analytical modelling approach for cutting forces in near-orthogonal cutting of titanium alloy Ti6Al4V. The catastrophic shear instability in the primary shear plane is assumed as a semi-static process. An analytical approach is used to evaluate chip thicknesses and forces in the near-orthogonal cutting process. The shear flow stress of the material is modelled by using the Johnson–Cook constitutive material law where the strain hardening, strain rate sensitivity and thermal softening behaviours are coupled. The thermal equations with non-uniform heat partitions along the tool–chip interface are solved by a finite difference method. The model prediction is verified with experimental data, where a good agreement in terms of the average cutting forces and chip thickness is shown. A comparison of the predicted temperatures with published data obtained by using the finite element method is also presented.

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