Torsional Fatigue of 63Sn-37Pb and Sn-0.7Cu Solders

2007 ◽  
Vol 353-358 ◽  
pp. 2908-2911
Author(s):  
Ning Bai ◽  
Xu Chen ◽  
Xin Li
Keyword(s):  
Steady State ◽  
Fatigue Strength ◽  
Fatigue Behavior ◽  
Equivalent Strain ◽  
Fatigue Tests ◽  
Load Drop ◽  
Torsional Fatigue ◽  
Von Mises ◽  
Fatigue Criterion ◽  
Better Than

A series of torsional fatigue tests were conducted on 63Sn-37Pb and Sn-0.7Cu solders. A continuous load drop was observed during the test. It was found that the load drop percentage had little effect on the elastic strain-life curve but strong effect on the plastic strain-life curve. The fatigue strength coefficient, fatigue strength exponent and fatigue ductility exponent had no great changes with the load drop. However, fatigue ductility coefficient showed a great difference and was linearly varying with load drop. A fatigue criterion of Coffin-Manson type was proposed in relation to load drop. The descending curve of the stress range with cycle was observed to consist of transient, steady state and tertiary regions. The percentage of load drop corresponding to the turning point from the steady state to the tertiary region was about 25% for all strain ranges of 63Sn-37Pb, and 30% for all strain ranges of Sn-0.7Cu. The torsional fatigue lives were correlated with von Mises equivalent strain amplitudes well. The fatigue behavior of Sn-0.7Cu is better than that of 63Sn-37Pb.

scholarly journals Elevated Temperature Axial and Torsional Fatigue Behavior of Haynes 188

1995 ◽  
Vol 117 (2) ◽  
pp. 191-199 ◽  
Author(s):  
Peter J. Bonacuse ◽  
Sreeramesh Kalluri
Keyword(s):  
Fatigue Life ◽  
Coefficient Of Thermal Expansion ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Strain Range ◽  
Equivalent Strain ◽  
Data Set ◽  
Torsional Strain ◽  
Torsional Fatigue ◽  
Von Mises

The results are reported for high-temperature axial and torsional low-cycle fatigue experiments performed at 760° C in air on thin-walled tubular specimens of Haynes 188, a wrought cobalt-base superalloy. Data are also presented for mean coefficient of thermal expansion, elastic modulus, and shear modulus at various temperatures from room to 1000° C, and monotonic and cyclic stress-strain curves in tension and in shear at 760° C. This data set is used to evaluate several multiaxial fatigue life models (most were originally developed for room temperature multiaxial life prediction) including von Mises equivalent strain range (ASME Boiler and Pressure Vessel Code), Manson-Halford, Modified Multiaxiality Factor (proposed in this paper). Modified Smith-Watson-Topper, and Fatemi-Socie-Kurath. At von Mises equivalent strain ranges (the torsional strain range divided by 3, taking the Poisson’s ratio to be 0.5), torsionally strained specimens lasted, on average, factors of 2 to 3 times longer than axially strained specimens. The Modified Multiaxiality Factor approach shows promise as a useful method of estimating torsional fatigue life from axial fatigue data at high temperatures. Several difficulties arose with the specimen geometry and extensometry used in these experiments. Cracking at extensometer probe indentations was a problem at smaller strain ranges. Also, as the largest axial and torsional strain range fatigue tests neared completion, a small amount of specimen buckling was observed.

scholarly journals Effects of thermomechanical history and environment on the fatigue behavior of (β)-Ti-Nb implant alloys

2018 ◽  
Vol 165 ◽  
pp. 06001 ◽  
Author(s):  
André Reck ◽  
Stefan Pilz ◽  
Ulrich Thormann ◽  
Volker Alt ◽  
Annett Gebert ◽  
...  
Keyword(s):  
Fatigue Strength ◽  
Cyclic Loading ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
Grain Structure ◽  
Fatigue Properties ◽  
Β Phase ◽  
Α Phase ◽  
Nb Content ◽  
Implant Alloys

This study examined the fatigue properties of a newly developed cast and thermomechanical processed (β)-Ti-40Nb alloy for a possible application as biomedical alloy due to exceptional low Young’s modulus (64-73 GPa), high corrosion resistance and ductility (20-26%). Focusing on the influence of two microstructural states with fully recrystallized β-grain structure as well as an aged condition with nanometer-sized ω-precipitates, tension-compression fatigue tests (R=-1) were carried out under lab-air and showed significant differences depending on the β-phase stability under cyclic loading. Present ω- precipitates stabilized the β-phase against martensitic α’’ phase transformations leading to an increased fatigue limit of 288 MPa compared to the recrystallized state (225 MPa), where mechanical polishing and subsequent cyclic loading led to formation of α’’-phase due to the metastability of the β-phase. Additional studied commercially available (β)-Ti-45Nb alloy revealed slightly higher fatigue strength (300 MPa) and suggest a change in the dominating cyclic deformation mechanisms according to the sensitive dependence on the Nb-content. Further tests in simulated body fluid (SBF) at 37°C showed no decrease in fatigue strength due to the effect of corrosion and prove the excellent corrosion fatigue resistance of this alloy type under given test conditions.

Fatigue Behavior of Age-Hardening Cu-6Ni-1.5Si Alloys with Different Grain Sizes

2021 ◽  
Vol 1016 ◽  
pp. 125-131
Author(s):  
Masahiro Goto ◽  
T. Yamamoto ◽  
S.Z. Han ◽  
J. Kitamura ◽  
J.H. Ahn ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Grain Size ◽  
Fatigue Strength ◽  
Solution Heat Treatment ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
The Other ◽  
Age Hardening ◽  
Grain Sizes ◽  
Thermomechanical Processes

On the thermomechanical treatments of Cu-Ni-Si alloy, cold-rolling (CR) before solution heat treatment (SHT) is commonly conducted to eliminate defects in a casting slab. In addition, a rolling is applied to reduce/adjust the thickness of casting slab before SHT. In a heavily deformed microstructure by CR, on the other hand, grain growth during a heating in SHT is likely to occur as the result of recrystallization. In general, tensile strength and fatigue strength tend to decrease with an increase in the grain size. However, the effect of difference in grain sizes produced by with and without CR before SHT on the fatigue strength is unclear. In the present study, fatigue tests of Cu-6Ni-Si alloy smooth specimens with a grain fabricated through different thermomechanical processes were conducted. The fatigue behavior of Cu-Ni-Si alloy was discussed.

Effect of Weld Geometry on the Fatigue Behaviour of Umbilical Super Duplex Stainless Steel Tubes

2017 ◽  
Author(s):  
Hauwa Raji ◽  
Jamie Fletcher Woods
Keyword(s):  
Stainless Steel ◽  
Fatigue Strength ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
Super Duplex Stainless Steel ◽  
Steel Tubes ◽  
Weld Geometry ◽  
Weld Profile ◽  
Weld Toe ◽  
Toe Angle

The fatigue behavior of welded components is complicated by many factors intrinsic to the nature of welded joints. The mechanical properties of the material, the welding process and position, the type and geometry of the weld and the residual stress distribution across the weld are a few factors affecting fatigue behavior. Published studies [1, 2] have shown that weld geometry is significantly important in determining the fatigue strength of the weld. For a given weld geometry, the fatigue strength is determined by the severity of the stress concentration at the weld toe or at weld defects and by the soundness of the weld metal. The effect of external weld geometry profile on the fatigue behavior of welded small bore super duplex umbilical steel tubes is investigated. Root cause analysis consisting of fractography, metallography and weld profile measurement is carried out on pairs of fatigue failure samples which were tested at the same stress range but failed at significantly different number of cycles. The samples are selected from Technip Umbilicals Ltd (TU) fatigue database. Following the failure analysis, weld geometric profile measurements are performed on fatigue test samples that were prepared for testing. The weld profile was measured in terms of the external weld cap height, weld width and external linear misalignment. Axial fatigue tests are carried out on these samples which are pre-strained before test to simulate the plastic bending cycles typically experienced during the manufacturing and installation processes prior to operational service. The fatigue tests results are interrogated together with the measured geometric data to identify trends and anomalies. Key weld geometric fatigue performance criteria are subsequently identified. For the welded super duplex stainless steel (SDSS) tubes studied, the height of the weld and the weld toe angle provided the best correlation with fatigue life — shorter lives were obtained from specimens with the highest weld aspect ratio (weld height to width) and lowest weld toe angle.

FATIGUE TEST OF STEEL GIRDER WEB PENETRATION DETAILS WITH A SLIT

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Naoto Yoshida ◽  
Masahiro Sakano ◽  
Hideyuki Konishi ◽  
Takashi Fujii
Keyword(s):  
Fatigue Strength ◽  
Fatigue Behavior ◽  
Fatigue Crack Initiation ◽  
Fatigue Cracking ◽  
Highway Bridges ◽  
Strength Properties ◽  
Fatigue Tests ◽  
Bottom Surface ◽  
Steel Girder ◽  
Propagation Behavior

Fatigue cracking in steel girder web penetration details is so dangerous that it can break steel girders. A one-meter-long crack was detected in Yamazoe Bridge in 2006. Since a number of highway bridges with such web penetration details may exist in Japan, it is of urgent importance to understand these fatigue-strength properties. However, few fatigue tests have been reported on steel girder web penetration details. The purpose of this study is to clarify fatigue behavior of steel girder web penetration details with a slit through fatigue tests of specimens with these details. We designed and fabricated girder specimens that have steel girder web penetration details, in which cross-beam bottom flanges are connected to each top or bottom surface of a slit by welding. First, we conducted static loading tests to understand the stress distributions around web penetration details. Second, we conducted fatigue tests to examine fatigue crack initiation and propagation behavior and fatigue strength.

scholarly journals Evaluation of Estimation Methods for Shear Fatigue Properties and Correlations with Uniaxial Fatigue Properties for Steels and Titanium Alloys

2018 ◽  
Vol 165 ◽  
pp. 16012 ◽  
Author(s):  
Shahriar Sharifimehr ◽  
Ali Fatemi
Keyword(s):  
Titanium Alloys ◽  
Inconel 718 ◽  
Fatigue Behavior ◽  
Estimation Method ◽  
Fatigue Tests ◽  
Estimation Methods ◽  
Fatigue Properties ◽  
Modified Method ◽  
Shear Fatigue ◽  
Von Mises

The goal of this study was to evaluate the accuracy of different methods in correlating uniaxial fatigue properties to shear fatigue properties, as well as finding a reliable estimation method which is able to predict the shear fatigue behavior of steels and titanium alloys from their monotonic properties. In order to do so, axial monotonic as well as axial and torsion fatigue tests were performed on two types of steel and a Ti-6Al-4V alloy. The results of these tests along with test results of 23 types of carbon steel, Inconel 718, and three types of titanium alloys commonly used in the industry were analyzed. It was found that von Mises and maximum principal strain criteria were able to effectively correlate uniaxial fatigue properties to shear fatigue properties for ductile and brittle behaving materials, respectively. Also, it was observed that for steels and Inconel 718 obtaining shear fatigue properties from uniaxial fatigue properties which are in turn calculated from Roessle-Fatemi estimation method resulted in reasonable estimations when compared to experimentally obtained uniaxial fatigue properties. Furthermore, a modification was made to the Roessle-Fatemi hardness method in order to adjust it to fatigue behavior of titanium alloys. The modified method, which was derived from uniaxial fatigue properties of titanium alloys with Brinell hardness between 240 and 353 proved to be accurate in predicting the shear fatigue behaviors.

scholarly journals Multiaxial Fatigue Behavior of High-Density Polyethylene (HDPE) Including Notch Effect: Experiments and Modeling

2019 ◽  
Vol 300 ◽  
pp. 05001 ◽  
Author(s):  
Mohammadreza Amjadi ◽  
Ali Fatemi
Keyword(s):  
High Density Polyethylene ◽  
Fatigue Behavior ◽  
Equivalent Stress ◽  
Fatigue Tests ◽  
Multiaxial Fatigue ◽  
High Density ◽  
Analytical Models ◽  
Axial Torsion ◽  
Stress Concentration Effect ◽  
Von Mises

High-Density Polyethylene (HDPE) is used in many industries with many applications from automotive industry to biomedical implants. It can be manufactured using different processing techniques including compression molding, injection molding, and blow molding. Multiaxial loading and non-proportionality between different loading sources are inevitable in many applications. It is shown that the common multiaxial fatigue criteria such as von Mises equivalent stress are not able to correlate the multiaxial fatigue data. In this study, multiaxial fatigue behavior of neat HDPE is investigated using hollow tubular specimens through experimental fatigue tests. Axial, torsion, and combined in phase and out-of-phase axial-torsion fatigue tests were conducted. Stress concentration effect on multiaxial fatigue behavior was also studied. Experimental results and analytical models used to account for the aforementioned effects are presented and discussed in this paper.

Fatigue Strength Assessment for High Strength Steel Welded Joints

2010 ◽  
Author(s):  
Ho Jung Kim ◽  
Sung Won Kang ◽  
Jae Myung Lee ◽  
Myung Hyun Kim
Keyword(s):  
Fatigue Strength ◽  
Welded Joints ◽  
High Strength Steel ◽  
Fatigue Behavior ◽  
High Strength ◽  
Fatigue Tests ◽  
Cold Metal Transfer ◽  
Strength Assessment ◽  
Back Plate ◽  
Cold Metal

The aim of the present paper is to investigate and to compare the fatigue characteristics of butt welded joints made of high strength steel with tensile strength 700MPa. The influence of different back plate materials and the groove shapes of copper backing are investigated. Various backing methods have been used in the steel construction industries, but steel backing, which is the most frequently used, sometimes is not capable of providing sufficient fatigue strengths for welded joint, particularly for high strength steel. Therefore, alternative backing methods have been investigated in order to improve the fatigue strength by employing ceramic backing, CMT (Cold Metal Transfer) [1] and copper backing. The main objective of the work is to estimate the fatigue test results for improving fatigue strength by comparing different backing materials and groove shapes. A series of fatigue tests with different types of backings has been carried out to obtain the fatigue life of butt welded joints. It was observed that the fatigue behavior of welded joints can be substantially improved by changing back bead shapes. The result has shown that the back bead shape of copper backing is better than others except for that of CMT, accompanied by improved fatigue strength.

A STUDY ON THE FRETTING FATIGUE LIFE OF ZIRCALOY ALLOYS

2008 ◽  
Vol 22 (11) ◽  
pp. 851-856
Author(s):  
JAE-DO KWON ◽  
DAE-KYU PARK ◽  
SEUNG-WAN WOO ◽  
YOUNG-SUCK CHAI
Keyword(s):  
Fatigue Life ◽  
Fatigue Strength ◽  
Nuclear Power ◽  
Power Plants ◽  
Structural Integrity ◽  
Fatigue Behavior ◽  
Fretting Fatigue ◽  
Mechanical Tests ◽  
Fatigue Tests ◽  
Cyclic Damage

Studies on the strength and fatigue life of machines and structures have been conducted in accordance with the development of modern industries. In particular, fine and repetitive cyclic damage occurring in contact regions has been known to have an impact on fretting fatigue fractures. The main component of zircaloy alloy is Zr , and it possesses good mechanical characteristics at high temperatures. This alloy is used in the fuel rod material of nuclear power plants because of its excellent resistance. In this paper, the effect of the fretting damage on the fatigue behavior of the zircaloy alloy is studied. Further, various types of mechanical tests such as tension and plain fatigue tests are performed. Fretting fatigue tests are performed with a flat-flat contact configuration using a bridge-type contact pad and plate-type specimen. Through these experiments, it is found that the fretting fatigue strength decreases by about 80% as compared to the plain fatigue strength. Oblique cracks are observed in the initial stage of the fretting fatigue, in which damaged areas are found. These results can be used as the basic data for the structural integrity evaluation of corrosion-resisting alloys considering the fretting damages.

Fatigue behavior of hot-extruded Mg–10Gd–3Y magnesium alloy

2010 ◽  
Vol 25 (4) ◽  
pp. 773-783 ◽  
Author(s):  
Wen-Cai Liu ◽  
Jie Dong ◽  
Ping Zhang ◽  
Li Jin ◽  
Tao Peng ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Fatigue Strength ◽  
Magnesium Alloy ◽  
Precipitation Hardening ◽  
High Cycle Fatigue ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
Solid Solution Hardening ◽  
X Ray ◽  
Microstructure Observation

In this study, the influence of T5 heat treatment on tensile and fatigue behavior of hot-extruded Mg–10Gd–3Y (wt%) magnesium alloy has been investigated. High cycle fatigue tests were carried out at a stress rate (R) of −1 and a frequency of 100 Hz using hour-glass-shaped round specimens with a gauge diameter of 5.8 mm. The results show that fatigue strength (at 107 cycles) of Mg–10Gd–3Y magnesium alloy increases from 150 to 165 MPa after T5 heat treatment, i.e., the improvement of 10% in fatigue strength has been achieved. However, the crack growth resistance is lowered by T5 heat treatment. Results of microstructure observation and scanning electron microscopy-energy dispersive x-ray (SEM-EDX) analysis suggest that the fatigue strength in the Mg–10Gd–3Y magnesium alloy is determined by the threshold stress of basal slip, which is induced by solid solution hardening and precipitation hardening.

Sign in / Sign up

Export Citation Format

Share Document