Prediction of Statistical Distribution of Vibration-Induced Solder Fatigue Failure Considering Intrinsic Variations of Mechanical Properties of Anisotropic Sn-Rich Solder Alloys

Author(s):  
Hsiu-Ping Wei ◽  
Yu-Hsiang Yang ◽  
Bulong Wu ◽  
Bongtae Han
2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Madhuri Chandrashekhar Deshpande ◽  
Rajesh Chaudhari ◽  
Ramesh Narayanan ◽  
Harishwar Kale

Purpose This study aims to develop indium-based solders for cryogenic applications. Design/methodology/approach This paper aims to investigate mechanical properties of indium-based solder formulations at room temperature (RT, 27 °C) as well as at cryogenic temperature (CT, −196 °C) and subsequently to find out their suitability for cryogenic applications. After developing these alloys, mechanical properties such as tensile and impact strength were measured as per American Society for Testing and Materials standards at RT and at CT. Charpy impact test results were used to find out ductile to brittle transition temperature (DBTT). These properties were also evaluated after thermal cycling (TC) to find out effect of thermal stress. Scanning electron microscope analysis was performed to understand fracture mechanism. Results indicate that amongst the solder alloys that have been studied in this work, In-34Bi solder alloy has the best all-round mechanical properties at RT, CT and after TC. Findings It can be concluded from the results of this work that In-34Bi solder alloy has best all-round mechanical properties at RT, CT and after TC and therefore is the most appropriate solder alloy amongst the alloys that have been studied in this work for cryogenic applications Originality/value DBTT of indium-based solder alloys has not been found out in the work done so far in this category. DBTT is necessary to decide safe working temperature range of the alloy. Also the effect of TC, which is one of the major reasons of failure, was not studied so far. These parameters are studied in this work.


2010 ◽  
Vol 2010 (1) ◽  
pp. 000314-000318
Author(s):  
Tong Jiang ◽  
Fubin Song ◽  
Chaoran Yang ◽  
S. W. Ricky Lee

The enforcement of environmental legislation is pushing electronic products to take lead-free solder alloys as the substitute of traditional lead-tin solder alloys. Applications of such alloys require a better understanding of their mechanical behaviors. The mechanical properties of the lead-free solders and IMC layers are affected by the thermal aging. The lead-free solder joints on the pads subject to thermal aging test lead to IMC growth and cause corresponding reliability concerns. In this paper, the mechanical properties of the lead-free solders and IMCs were characterized by nanoindentation. Both the Sn-rich phase and Ag3Sn + β-Sn phase in the lead-free solder joint exhibit strain rate depended and aging soften effect. When lead-free solder joints were subject to thermal aging, Young's modulus of the (Cu, Ni)6Sn5 IMC and Cu6Sn5 IMC changed in very small range. While the hardness value decreased with the increasing of the thermal aging time.


2019 ◽  
Vol 45 (7) ◽  
pp. 707-710 ◽  
Author(s):  
Yu. M. Boiko ◽  
V. A. Marikhin ◽  
O. A. Moskalyuk ◽  
L. P. Myasnikova ◽  
E. S. Tsobkallo

Friction ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 1039-1050
Author(s):  
Wei Wang ◽  
Huaiju Liu ◽  
Caichao Zhu ◽  
Jinyuan Tang ◽  
Chenxu Jiang

AbstractCarburized gears are widely used in geared machines such as wind turbines. Contact fatigue problems occur in engineering practice, reducing reliabilities of machines. Contact fatigue failures are related to many factors, such as gradients of mechanical properties of the hardening layer. In this work, an elastic-plastic contact model of a carburized gear is developed based on the finite element method to evaluate contact fatigue failure risk, considering variations in hardness and strength. The Dang Van multiaxial equivalent stress is calculated via Python coding within the Abaqus framework. The gradient of yield strength along the depth from case to core is considered. The concept of local material fatigue failure risk is defined to evaluate the probability of pitting failure. The effects of design factors, such as the case hardening depth (CHD), surface hardness, and contact pressure on fatigue failure risk, are studied. As the CHD increases or the surface hardness decreases, the risk of deep spalling failure reduces. The increase in surface hardness leads to a decreased risk of pitting failure, while the variation in CHD hardly affects the pitting failure risk.


2020 ◽  
Vol 31 (24) ◽  
pp. 22926-22932
Author(s):  
Hong-Sub Joo ◽  
Choong-Jae Lee ◽  
Kyung Deuk Min ◽  
Byeong-Uk Hwang ◽  
Seung-Boo Jung

2019 ◽  
Vol 809 ◽  
pp. 131-139
Author(s):  
Yuan Shi ◽  
Yan Lei Xiu ◽  
Dietmar Koch

Because of the excellent fracture toughness and oxidation resistance, carbon fiber reinforced silicon carbide (C/C-SiC or C/SiC) exhibits a sound potential in various application areas such as aerospace technology and high-performance braking systems. For the composite’s reliable design, production, examination, quality assurance and verification, however, the statistical distribution of mechanical properties is of crucial interest and has not been investigated in detail yet. In this work, the strength values of C/C-SiC composite, which was developed via Liquid Silicon Infiltration at the Institute of Structures and Design of German Aerospace Center (DLR), were measured under tensile, bending and compression load. The results were analyzed by normal and Weibull distribution statistics and verified by Kolmogorov–Smirnov-test (KS-test) and Anderson–Darling-test (AD-test). Based on the statistical analysis, the 4PB-strength of C/C-SiC composite can be better described by Weibull distribution. In comparison, normal distribution is more suitable for the compression strength. The influence of different numbers of coupons on the mechanical properties has been identified. A scanning electron microscope (SEM) was employed to analyze the fracture surface, which confirmed that the different statistical distribution of strength values was caused by various failure mechanisms.


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