High and Low Temperature Strain-Life Behavior of a Pb Rich Solder

1990 ◽  
Vol 112 (2) ◽  
pp. 123-128 ◽  
Author(s):  
H. D. Solomon

This paper describes the fatigue behavior of a Pb rich solder, 92.5Pb, 2.5Ag, 5.0Sn (Indalloy 151), tested at −50°C and +150°C. The results are compared to previously reported studies of 60Sn/40Pb solder and to tests of Indalloy 151 performed at 35° C. The Coffin-Manson exponent is larger at all temperatures for the Indalloy 151 compared to the 60Sn/40Pb, but this effect is especially pronounced at +150° C where the exponent is 0.85 for the Indalloy 151 and only 0.35 for the 60Sn/40Pb. This gives rise to a crossover in the behavior of the two solders with the Indalloy 151 exhibiting a longer fatigue life at high strains and the 60Sn/40Pb exhibiting superior behavior at low strains.

2007 ◽  
Vol 353-358 ◽  
pp. 142-145 ◽  
Author(s):  
Ki Weon Kang ◽  
Byeong Choon Goo ◽  
J.H. Kim ◽  
Heung Seob Kim ◽  
Jung Kyu Kim

This paper deals with the fatigue behavior and its statistical properties of SM490A steel at various temperatures, which is utilized in the railway vehicle. For these goals, the tensile ad fatigue tests were performed by using a servo-hydraulic fatigue testing machine at three temperatures: +20°C, -10°C and -40°C. The static strength and fatigue limits of SM490A steel were increased with decreasing of test temperature. The probabilistic properties of fatigue behavior are investigated by means of probabilistic stress-life (P-S-N) curve and they are well in conformance with the experimental results regardless of temperature. Also, based on P-S-N curves, the variation of fatigue life is investigated and as the temperature decreases, the variation of fatigue life increases moderately.


2010 ◽  
Vol 25 (5) ◽  
pp. 966-971 ◽  
Author(s):  
Seong-Gu Hong ◽  
Sung Hyuk Park ◽  
Yong-Hak Huh ◽  
Chong Soo Lee

The anisotropy in the fatigue behavior of rolled Mg–3Al–1Zn alloy between the rolling direction and normal direction to the rolling plane was investigated. The {10-12} twinning–detwinning characteristics were found to play key roles in the anisotropic fatigue deformation behavior by inducing a change in the predominant plastic deformation mechanism, which controlled the flow stress and finally influenced the fatigue resistance by generating mean stress. Energy-based approach was successfully used to describe anisotropic fatigue life behavior.


1989 ◽  
Vol 111 (2) ◽  
pp. 75-82 ◽  
Author(s):  
H. D. Solomon

This paper describes low cycle fatigue test run at −50°C, 35°C, 125°C, and 150°C on thin 60 Sn/40 Pb solder joints, tested in simple shear. The low cycle fatigue behavior was found to be a function of the criteria used to define the fatigue life. Different drops in the hysteresis load, measured when a constant plastic strain is being applied, was used to define failure. Not only was the magnitude of the fatigue life a function of the load drop definition for failure, it was also found that the Coffin-Manson low cycle fatigue exponent was a function of this definition. The choice of dependent variable for the curve fitting procedure used to calculate the Coffin-Manson exponent is also considered.


1987 ◽  
Vol 109 (3) ◽  
pp. 244-251 ◽  
Author(s):  
J. Wittenauer ◽  
O. D. Sherby

Laminates based on ultrahigh carbon steel were prepared and found to exhibit enhanced fatigue life as compared to a monolithic reference material. This result was achieved through the insertion of weak interlaminar regions of copper into the layered material during preparation of the laminates. The presence of these regions allowed for the operation of a delamination mechanism in advance of the propagating fatigue crack. The result was interlaminar separation and associated crack blunting. Stress-life curves show that an increase in life by as much as a factor of four is achieved for these materials when compared to monolithic specimens of similar processing history.


2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110112
Author(s):  
Li Xun ◽  
Wang Ziming ◽  
Yang Shenliang ◽  
Guo Zhiyuan ◽  
Zhou Yongxin ◽  
...  

Titanium alloy Ti1023 is a typical difficult-to-cut material. Tool wear is easy to occur in machining Ti1023, which has a significant negative effect on surface integrity. Turning is one of the common methods to machine Ti1023 parts and machined surface integrity has a direct influence on the fatigue life of parts. To control surface integrity and improve anti-fatigue behavior of Ti1023 parts, it has an important significance to study the influence of tool wear on the surface integrity and fatigue life of Ti1023 in turning. Therefore, the effect of tool wear on the surface roughness, microhardness, residual stress, and plastic deformation layer of Ti1023 workpieces by turning and low-cycle fatigue tests were studied. Meanwhile, the influence mechanism of surface integrity on anti-fatigue behavior also was analyzed. The experimental results show that the change of surface roughness caused by worn tools has the most influence on anti-fatigue behavior when the tool wear VB is from 0.05 to 0.25 mm. On the other hand, the plastic deformation layer on the machined surface could properly improve the anti-fatigue behavior of specimens that were proved in the experiments. However, the higher surface roughness and significant surface defects on surface machined utilizing the worn tool with VB = 0.30 mm, which leads the anti-fatigue behavior of specimens to decrease sharply. Therefore, to ensure the anti-fatigue behavior of parts, the value of turning tool wear VB must be rigorously controlled under 0.30 mm during finishing machining of titanium alloy Ti1023.


2021 ◽  
Vol 9 (6) ◽  
pp. 1880-1887
Author(s):  
Xia Sun ◽  
Shaoshuai He ◽  
Mengmeng Yao ◽  
Xiaojun Wu ◽  
Haitao Zhang ◽  
...  

Fully-physically crosslinked hydrogels with strain sensitivity and anti-freezing properties for wireless sensing and low temperature sensing were prepared.


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2171
Author(s):  
Armin Yousefi ◽  
Ahmad Serjouei ◽  
Reza Hedayati ◽  
Mahdi Bodaghi

In the present study, the fatigue behavior and tensile strength of A6061-T4 aluminum alloy, joined by friction stir spot welding (FSSW), are numerically investigated. The 3D finite element model (FEM) is used to analyze the FSSW joint by means of Abaqus software. The tensile strength is determined for FSSW joints with both a probe hole and a refilled probe hole. In order to calculate the fatigue life of FSSW joints, the hysteresis loop is first determined, and then the plastic strain amplitude is calculated. Finally, by using the Coffin-Manson equation, fatigue life is predicted. The results were verified against available experimental data from other literature, and a good agreement was observed between the FEM results and experimental data. The results showed that the joint’s tensile strength without a probe hole (refilled hole) is higher than the joint with a probe hole. Therefore, re-filling the probe hole is an effective method for structures jointed by FSSW subjected to a static load. The fatigue strength of the joint with a re-filled probe hole was nearly the same as the structure with a probe hole at low applied loads. Additionally, at a high applied load, the fatigue strength of joints with a refilled probe hole was slightly lower than the joint with a probe hole.


Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1421
Author(s):  
Armin Yousefi ◽  
Saman Jolaiy ◽  
Reza Hedayati ◽  
Ahmad Serjouei ◽  
Mahdi Bodaghi

Bonded patches are widely used in several industry sectors for repairing damaged plates, cracks in metallic structures, and reinforcement of damaged structures. Composite patches have optimal properties such as high strength-to-weight ratio, easiness in being applied, and high flexibility. Due to recent rapid growth in the aerospace industry, analyses of adhesively bonded patches applicable to repairing cracked structures have become of great significance. In the present study, the fatigue behavior of the aluminum alloy, repaired by a double-sided glass/epoxy composite patch, is studied numerically. More specifically, the effect of applying a double-sided composite patch on the fatigue life improvement of a damaged aluminum 6061-T6 is analyzed. 3D finite element numerical modeling is performed to analyze the fatigue performance of both repaired and unrepaired aluminum plates using the Abaqus package. To determine the fatigue life of the aluminum 6061-T6 plate, first, the hysteresis loop is determined, and afterward, the plastic strain amplitude is calculated. Finally, by using the Coffin-Manson equation, fatigue life is predicted and validated against the available experimental data from the literature. Results reveal that composite patches increase the fatigue life of cracked structures significantly, ranging from 55% to 100% for different applied stresses.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3073
Author(s):  
Abbas Mukhtar Adnan ◽  
Chaofeng Lü ◽  
Xue Luo ◽  
Jinchang Wang

This study has investigated the impact of graphene oxide (GO) in enhancing the performance properties of an asphalt binder. The control asphalt binder (60/70 PEN) was blended with GO in contents of 0%, 0.5%, 1%, 1.5%, 2%, and 2.5%. The permanent deformation behavior of the modified asphalt binders was evaluated based on the zero shear viscosity (ZSV) parameter through a steady shear test approach. Superpave fatigue test and the linear amplitude sweep (LAS) method were used to evaluate the fatigue behavior of the binders. A bending beam rheometer (BBR) test was conducted to evaluate the low-temperature cracking behavior. Furthermore, the storage stability of the binders was investigated using a separation test. The results of the ZSV test showed that GO considerably enhanced the steady shear viscosity and ZSV value, showing a significant contribution of the GO to the deformation resistance; moreover, GO modification changed the asphalt binder’s behavior from Newtonian to shear-thinning flow. A notable improvement in fatigue life was observed with the addition of GO to the binder based on the LAS test results and Superpave fatigue parameter. The BBR test results revealed that compared to the control asphalt, the GO-modified binders showed lower creep stiffness (S) and higher creep rate (m-value), indicating increased cracking resistance at low temperatures. Finally, the GO-modified asphalt binders exhibited good storage stability under high temperatures.


Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 476 ◽  
Author(s):  
Chao Gu ◽  
Min Wang ◽  
Yanping Bao ◽  
Fuming Wang ◽  
Junhe Lian

The fatigue property is significantly affected by the inner inclusions in steel. Due to the inhomogeneity of inclusion distribution in the micro-scale, it is not straightforward to quantify the effect of inclusions on fatigue behavior. Various investigations have been performed to correlate the inclusion characteristics, such as inclusion fraction, size, and composition, with fatigue life. However, these studies are generally based on vast types of steels and even for a similar steel grade, the alloy concept and microstructure information can still be of non-negligible difference. For a quantitative analysis of the fatigue life improvement with respect to the inclusion engineering, a systematic and carefully designed study is still needed to explore the engineering dimensions of inclusions. Therefore, in this study, three types of bearing steels with inclusions of the same types, but different sizes and amounts, were produced with 50 kg hot state experiments. The following forging and heat treatment procedures were kept consistent to ensure that the only controlled variable is inclusion. The fatigue properties were compared and the inclusions that triggered the fatigue cracks were analyzed to deduce the critical sizes of inclusions in terms of fatigue failure. The results show that the critical sizes of different inclusion types vary in bearing steels. The critical size of the spinel is 8.5 μm and the critical size of the calcium aluminate is 13.5 μm under the fatigue stress of 1200 MPa. In addition, with the increase of the cleanliness of bearing steels, the improvement of fatigue properties will reach saturation. Under this condition, further increasing of the cleanliness of the bearing steel will not contribute to the improvement of fatigue property for the investigated alloy and process design.


Sign in / Sign up

Export Citation Format

Share Document