A thermomechanical constitutive model for investigating the fatigue behavior of Sn‐rich solder under thermal cycle loading

Abstract

Based on crystal plastic theory, a novel thermomechanical constitutive model was proposed for Sn-rich solder. Material parameters of the proposed constitutive model were determined by fitting the stress-strain curves under uniaxial tensile testings. Combined with the proposed model and the material parameters, crystal plastic finite element method was used to investigate the effects of the microstructure features of grain orientation, grain boundary, and intermetallic compound on the fatigue behaviors of Sn-rich solder joint under the condition of thermal cycle loading. Results showed that the mean absolute percentage error between the simulation and experimental tensile curves was 3.50%, and the three microstructure features affected the fatigue behaviors of Sn-rich solder from different aspects, which were analyzed in detail. Besides, it was concluded that the proposed constitutive model could be effectively used to investigate the fatigue behaviors of Sn-rich solder joint from micro perspective.

Multi-scale plasticity homogenization of Sn–3Ag-0.5Cu: From β-Sn micropillars to polycrystals with intermetallics

“…The resulting predicted temperature-dependent average flow stresses versus applied strain rate for the polycrystal model are shown in Figure 11 (for the four applied strain rates). In addition, a set of independent tensile test results [5,[58][59][60][61][62] have also been included showing generally good agreement with the predicted results. While the IMC size range relevant to the tests was not reported, it is likely to be consistent with the range selected ( 𝑟̅ 𝐼𝑀𝐶 =0.11 µm and 𝑟̅ 𝐼𝑀𝐶 =1.88 µm).…”

Viscoplastic constitutive model considering strain rate sensitivity under multiaxial thermomechanical fatigue loading

“…High‐temperature parts like aeroengine compressor disk bear the combined action of centrifugal loading, torsional loading, aerodynamic loading, and so on during service, that is, multiaxial thermomechanical fatigue (MTMF), which will lead to material fatigue, creep, and oxidation 1–9 . Moreover, the amount of these damages will change with the change of material type or loading path, which seriously affects the failure life of high‐temperature equipment 10–12 .…”

“…High-temperature parts like aeroengine compressor disk bear the combined action of centrifugal loading, torsional loading, aerodynamic loading, and so on during service, that is, multiaxial thermomechanical fatigue (MTMF), which will lead to material fatigue, creep, and oxidation. [1][2][3][4][5][6][7][8][9] Moreover, the amount of these damages will change with the change of material type or loading path, which seriously affects the failure life of hightemperature equipment. [10][11][12] At present, modern aeroengines continue to pursue high thrust weight ratio, and their service reliability and safety need to be guaranteed; therefore, damage calculation and life assessment for MTMF have become a new hot issue.…”

A new unified creep‐plasticity constitutive model coupled with damage for viscoplastic materials subjected to fatigue loading

“…With the empirical formulae of fatigue life essentially based on the Coffin–Mansion model, it is challenging to accurately describe and simulate the fatigue damage and life of viscoplastic solders 18 . As a possible method to solve this problem, the theory of continuous damage mechanics has been explored in recent years with the purpose of considering the damage state for materials during loading by defining thermodynamic state variables 19–22 . Zhang et al 23 developed an analytical model based on the steady‐state creep model to simulate the mechanical tests at different temperatures, strain rates, and stresses.…”

“…18 As a possible method to solve this problem, the theory of continuous damage mechanics has been explored in recent years with the purpose of considering the damage state for materials during loading by defining thermodynamic state variables. [19][20][21][22] Zhang et al 23 developed an analytical model based on the steady-state creep model to simulate the mechanical tests at different temperatures, strain rates, and stresses. Asasaari et al 24 introduced the damage mechanics concept to evaluate the deformation and failure process of solder joints during reflow cooling.…”