Article
Polymer Science
Peng Zhang, Songbai Xue, Lu Liu, Jianhao Wang, Hiroaki Tatsumi, Hiroshi Nishikawa
Summary: This study investigated the microstructure evolution and mechanical properties of novel epoxy composite SAC305 solder joints after aging, and found that the epoxy composite joints had a lower growth rate of intermetallic compounds and significantly improved mechanical properties.
Article
Engineering, Mechanical
Mingwei Xie, Gang Chen
Summary: This study investigated the mechanical response of Sn-based lead-free SAC305 solder under thermomechanical cyclic loading, developed a crystal plasticity model for prediction, and analyzed the cyclic softening behavior of the solder.
INTERNATIONAL JOURNAL OF PLASTICITY
(2022)
Article
Mechanics
Cong Liu, Daquan Xia, Mizhe Tian, Shiqi Chen, Guisheng Gan, Yunfei Du, Xin Liu, Zhaoqi Jiang, Yiping Wu, Yanlong Ma
Summary: This research investigated the effects of rapid thermal shock cycle on the internal cracks, microstructure, and internal cracks of SAC305 ball. The results showed that surface cracks of the solder ball widen and deepen with an increase in rapid thermal shock cycles. The microstructure of the solder ball becomes more consistent and the grains are refined due to recrystallization. The volume and surface area of internal cracks initially increase and then decrease with thermal shock cycles, but are repaired after 4500 cycles. It was also observed that the occurrence of internal cracks is related to the grain orientation inside the solder ball.
ENGINEERING FRACTURE MECHANICS
(2022)
Article
Crystallography
Mohammed Abueed, Raed Al Athamneh, Moayad Tanash, Sa'd Hamasha
Summary: The study investigates the effects of creep and fatigue on joint reliability by subjecting individual solder junctions to accelerated shear fatigue testing. Results show that larger stress magnitudes or longer dwell periods significantly decrease fatigue life and increase plastic work and plastic strain. The housing conditions also play a significant role in the damage.
Article
Engineering, Mechanical
Mingwei Xie, Gang Chen, Jingtai Yu, Yuntao Wu, Xiao Liu, Jing Yang, Weiling Xu
Summary: In this study, the effect of thermal aging on the mechanical properties of SAC305 solder was evaluated using nanoindentation method. A dual-phase CPFEM model was developed to simulate the thermal aging effects. The experimental results showed that the mechanical properties of the solder weaken with aging, and the accuracy of the model was verified.
INTERNATIONAL JOURNAL OF PLASTICITY
(2022)
Article
Materials Science, Multidisciplinary
M. W. Xie, G. Chen, J. Yang, W. L. Xu
Summary: In this study, the mechanical properties of SAC305 solder were investigated under different temperatures and strain rates using experimental and modeling approaches. The results showed that grain orientation played a crucial role in determining the dispersion of poly-crystalline macroscopic stress-strain curves, and adjustments of parameters could successfully describe the temperature-dependent behavior of the solder. Moreover, the rate-dependent effects on the stress-strain response of SAC305 solder were weakened with increasing temperature, which was simulated by modifying the rate-dependent parameter in the model.
MECHANICS OF MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Duncan W. MacLachlan, Vasilis Karamitros, Fionn P. E. Dunne
Summary: This paper proposes an engineering approach to the problem of fatigue crack initiation at the microstructural scale. The initiation of fatigue cracks is broken down into separate processes, and a fundamental approach to modelling these processes has been developed. The method successfully correlates with fatigue data for a specific material.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2023)
Article
Engineering, Electrical & Electronic
Dania Bani Hani, Raed Al Athamneh, Sa'd Hamasha
Summary: This study investigates the effect of aging temperature on the fatigue and mechanical behavior of SAC305 solder joints using accelerated shear-fatigue and shear tests. The results indicate a major reduction in the reliability and shear strength of the solder joints with increasing the aging temperature.
IEEE TRANSACTIONS ON DEVICE AND MATERIALS RELIABILITY
(2022)
Article
Materials Science, Multidisciplinary
X. L. Ren, X. Y. Liu, S. Y. Shi, Y. P. Wang, N. Zhao
Summary: In this study, the morphologies of 8-Sn grains in different compositions of Sn-3.0Ag-0.5CuxIn solder balls and joints were characterized. Seven 8-Sn grain morphologies containing twinning relationship were found, and the 8-Sn grains were significantly refined when the In content exceeded 2wt%. Additionally, nucleus and growth models for the seven 8-Sn morphologies were established by combining the 8-Sn cell or cyclic twin structure with the preferred growth direction of 8-Sn dendrites.
MATERIALS CHARACTERIZATION
(2023)
Article
Metallurgy & Metallurgical Engineering
Suchart CHANTARAMANEE, Phairote SUNGKHAPHAITOON
Summary: The addition of a small amount of bismuth in SAC305 solder joints can improve their properties by refining the microstructure, reducing the melting temperature, and enhancing the mechanical performance.
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
(2021)
Article
Chemistry, Physical
Cong Xiong, Yong Xiao, Jian Zhang, Dan Luo, Russell Goodall
Summary: The study investigates the use of Ni-Cu/SAC composite solders with different Cu contents as interlayers for soldering Al alloy joints. The microstructure formation and evolution are found to be influenced by the Cu contents. Different initial phases and phase transitions are observed in Ni18Cu/SAC and Ni38Cu/SAC joints. The shear strength of the joints initially increases and then decreases with soldering time, with the Ni18Cu/SAC joints soldered for 10 minutes exhibiting the highest shear strength.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Engineering, Electrical & Electronic
Xin Mao, Ruhua Zhang, Xiong Yi, Xiaowu Hu, Yulong Li, Xiongxin Jiang
Summary: By utilizing Cu foams with different porosities and adjusting ultrasonic power, the microstructure of solder joints can be optimized to enhance shear strength. However, excessive ultrasonic power may lead to microcracks at the interface of the solder joint, subsequently reducing the shear strength.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2021)
Article
Materials Science, Multidisciplinary
Umair Ali, Hamza Khan, Muhammad Aamir, Khaled Giasin, Numan Habib, Muhammad Owais Awan
Summary: This study found that doping Bismuth into SAC305 can effectively refine microstructure, suppress the growth of intermetallic compounds, and improve mechanical properties. The best performance was observed with 3% Bismuth doping, which also resulted in a decrease in the melting temperature.
Article
Chemistry, Physical
Yuanyuan Qiao, Ning Zhao, Haitao Ma
Summary: The microstructure heredity of Cu/Sn-3.0Ag-0.5Cu(wt%)/Cu micro solder joints between sequential reflows was found to differ depending on the reflow method used, with temperature gradient reflow helping to maintain the preferred orientation structure of beta-Sn grains.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Engineering, Mechanical
Vincent Voet, Frederik Van Loock, Christophe De Fruytier, Aude Simar, Thomas Pardoen
Summary: Printed board assemblies are prone to fatigue cracking of solder joints caused by thermal expansion mismatch. Finite element simulations using traction-separation law and temperature-dependent elasto-viscoplastic model successfully predict the cracking process and joint response. The study also examines the impact of geometric dimensions, solder joint thickness, and PCB substrate parameters, leading to design optimization.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Engineering, Mechanical
Kai-Shang Li, Lv-Yi Cheng, Yilun Xu, Run-Zi Wang, Yong Zhang, Xian-Cheng Zhang, Shan-Tu Tu, Hideo Miura
Summary: A dual-scale modelling approach is developed in this paper to investigate the creep-fatigue behavior and predict crack initiation life for holed structures under multi-axial stress state. The results of macro- and micro-scale simulations are presented, and the predicted cycle numbers to crack initiation are in agreement with the experimental ones. The dual-scale modelling approach shows significant potential in both scientific and engineering aspects.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Chemistry, Physical
Y. Cui, C. M. Gourlay
Summary: The study investigates how different twin types and twin variants affect the growth morphology during solidification in primary Al45Cr7 and Al13Fe4 intermetallic compounds (IMCs). The number of twin variants increased with cooling rate, and cyclic twinning resulted in different growth morphologies depending on the twin variants present.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Multidisciplinary
Yangchao Deng, Guang Zeng, Jingwei Xian, Hongyi Zhan, Chuming Liu, Christopher M. Gourlay
Summary: In this study, the formation of intermetallic compounds during the solidification of multi-phase magnesium alloys was comprehensively investigated. The experimental results showed that Mg2Sn forms eutectic particles with 13-Mg17Al12 and r-MgAlZn, containing multiple phases. The lattice match between Mg2Sn and r-MgAlZn was found to be the best, with Mg2Sn being correlated with the icosahedral coordination in r-MgAlZn.
MATERIALS CHARACTERIZATION
(2022)
Article
Materials Science, Multidisciplinary
Liuqing Peng, Guang Zeng, Di Wang, Jingwei Xian, Shouxun Ji, Hongyi Zhan, Christopher M. Gourlay
Summary: This study investigates the formation of Al-Mn IMCs in Mg-9Al-0.7Zn-0.2Mn alloy produced by high-pressure die casting and direct chill casting. The results show that controlling solidification and filtration during casting is important for ensuring small Al-Mn intermetallic particles in these casting processes.
Article
Chemistry, Physical
L. Peng, G. Zeng, J. Xian, C. M. Gourlay
Summary: The influence of iron on the formation of Al-Mn-Fe intermetallic compounds (IMCs) has been investigated. It was found that the iron content affects the phase fractions and morphology of the IMCs.
Article
Engineering, Mechanical
Yilun Xu, Daniel S. Balint, Christian Greiner, Daniele Dini
Summary: Discrete dislocation plasticity calculations are used to investigate the response of a single crystal under sliding loading conditions with a rigid sinusoidal asperity contact. The study identifies lattice rotations and stored energy as the key factors causing microstructure change in the dislocation structure. Maps of surface slip initiation and substrate permanent deformation obtained from the calculations suggest ways to optimize the interface and microstructural material properties for different frictional loads.
Article
Nanoscience & Nanotechnology
Yilun Xu, Tianhong Gu, Jingwei Xian, Finn Giuliani, T. Ben Britton, Christopher M. Gourlay, Fionn P. E. Dunne
Summary: The mechanical properties and temperature sensitivity of beta-Sn single crystals and polycrystalline beta-Sn-rich alloys have been investigated using a combination of experimental and numerical methods. The results provide insights into the behavior of electronic solders under thermomechanical loading.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
N. Hou, J. W. Xian, A. Sugiyama, H. Yasuda, C. M. Gourlay
Summary: In this study, we investigated the morphology transitions of the β-Sn + Ag3Sn eutectic at increasing growth velocity. The orthorhombic Ag3Sn grew as faceted plates or rods with [010] growth direction and (001) as the largest facet in three eutectic growth morphologies. Reproducible β-Sn + Ag3Sn orientation relationships were observed in the latter two morphologies. The mechanisms of spacing adjustment and the reversible transition from plate to rod growth were studied for transient solidification after velocity changes.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Y. Cui, J. W. Xian, A. Zois, K. Marquardt, H. Yasuda, C. M. Gourlay
Summary: The factors affecting the nucleation and morphology of large Ag3Sn plates in solder joints are not well understood. This study investigates the faceted solidification of Ag3Sn and reveals transitions from single crystal plates to cyclic twinned plates and highly branched structures. Real-time X-ray imaging confirms that Ag3Sn cyclic twins originate from a common point during nucleation or the early stages of growth. Soldering to copper substrates catalyzes Ag3Sn nucleation through constitutional supercooling and geometrical catalysis.
Article
Engineering, Mechanical
Bjorn Kunzelmann, Pawel Rycerz, Yilun Xu, Nagaraj K. Arakere, Amir Kadiric
Summary: This paper investigates the application of linear elastic fracture mechanics (LEFM) principles in predicting the crack propagation of rolling contact fatigue (RCF) in machine elements such as rolling bearings and gears. Experimental tests are conducted on AISI 52100 bearing steel roller specimens to measure crack propagation rates and establish crack geometry. A numerical finite element model based on LEFM methods is developed to predict stress intensity factors (SIFs) during over-rolling, considering factors such as Hertzian contact stresses, contact friction, and crack face friction. The results show that LEFM can accurately predict the growth of RCF cracks and provide insights into the dominant propagation mode and the effects of crack face friction. The findings contribute to the development of tools for predicting the remaining useful life of machine components, enhancing the reliability of mechanical systems.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Chemistry, Physical
C. J. Lin, L. Peng, J. W. Xian, Q. Li, C. M. Gourlay
Summary: In hypoeutectic Mg-Al-based alloys, Mg17Al12 forms by a eutectic reaction that is usually divorced. The nucleation, growth, and morphology of Mg17Al12-containing eutectic in a multicomponent Mg-9Al-0.7Zn-0.2Mn alloy are investigated. Mg17Al12 forms an interconnected 3D skeleton and occasionally has a preferred orientation relationship with alpha-Mg. The degree of partially divorced growth depends on geometric measures, and fully coupled eutectic microstructures can be generated by manipulating the solidification time and cooling rate.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Yang Yang, Yangchao Deng, Ruifeng Zhang, Yuqing Su, Siyue Liu, Christopher M. Gourlay, Guang Zeng
Summary: This study investigates the correlation between microstructure and corrosion behavior of AZ series alloys using various techniques. The results show that a 3D interconnected eutectic network protects against localized corrosion in chloride solution. Additionally, Al-Mn intermetallics treated with a solution lead to filament corrosion instead of pitting corrosion, due to a reduction in potential difference.
Article
Materials Science, Multidisciplinary
Yilun Xu, Felicity F. Worsnop, David Dye, Fionn P. E. Dunne
Summary: The slip intermittency and stress oscillations observed in titanium alloy Ti-7Al-O are investigated using a discrete dislocation plasticity model. The results show that these phenomena are caused by dislocation escape during stress holds, governed by a thermal activation constitutive law. The stress drops due to basal slip are larger than those along prism due to their differing rate sensitivities, which has been previously observed in micropillar testing. It is suggested that interstitial oxygen suppresses stress oscillations by inhibiting the thermal activation process. Understanding these mechanisms is important for the design and safety assessment of jet engine titanium alloys subjected to dwell fatigue.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2023)
Article
Nanoscience & Nanotechnology
Tim M. Schwarz, Hongyi Zhan, Baptist Gault, Christopher M. Gourlay, Ingrid McCarroll
Summary: The peak-aged magnesium-aluminum-rare earth (Mg-Al-RE) alloy AE44-2, produced through high-pressure die casting, exhibits a 10% increase in yield strength due to the formation of nanoscale AlMn precipitates. Atom probe tomography reveals the presence of Ce-rich clusters in the dendritic region rather than the inter-dendritic alpha-Mg in the as cast state, indicating their formation is mainly determined by solidification kinetics rather than concentration. These Ce-rich clusters act as heterogeneous nucleation sites for the formation of Al10Mn7RE2 nanoscale precipitates during the T5 heat treatment, suggesting a potential pathway for tailoring mechanical properties.
SCRIPTA MATERIALIA
(2023)
