Evaluation of Time-Independent and Time-Dependent Strains of Lead-Free Solder by Stepped Ramp Loading Test
Evaluation of Time-Independent and Time-Dependent Strains of Lead-Free Solder by Stepped Ramp Loading Test
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DOI：
10.1115/1.3103951
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发表时间：
2009-06
影响因子：
1.6
通讯作者：
K. Ohguchi;K. Sasaki;S. Aso
中科院分区：
文献类型：
--
作者：
K. Ohguchi;K. Sasaki;S. Aso
本文提出了一种仅通过拉伸试验来估算无铅焊料弹塑性蠕变本构模型中基本材料常数的方法。该试验采用阶梯斜波加载，重复瞬时应变和应变保持。由瞬时应变部分的应力-应变关系得到与时间无关的应变，而由应变保持期间的应力-时间关系得到与时间有关的应变。基于所获得的时变和时变应变，确定了作者提出的弹塑性蠕变模型中的材料常数值。对一种锡-3.0Ag-0.5Cu焊料合金的粘塑性变形进行了数值模拟，验证了该方法的有效性。
This paper proposes a method to estimate basic material constants in an elasto-plastic-creep constitutive model for lead-free solders by conducting only a tensile test. The test employs a stepped ramp wave loading, which repeats instantaneous strain and strain maintenance. Time-independent strains are obtained from the stress-strain relations at the instantaneously strained parts, while the time-dependent strains are obtained from the stress-time relations during the strain maintaining periods. Based on the obtained time-independent and time-dependent strains, the values of the material constants in the elasto-plastic-creep model proposed by the authors are determined. Simulations of the viscoplastic deformations of a Sn―3.0Ag―0.5Cu solder alloy are also conducted to verify the validity of the proposed method.