Abstract A composite solder was prepared by adding different amount Ni modified multi-walled carbon nanotubes (MWCNTs) into the Sn-3.0Ag-0.5Cu (SAC305) solder. Experiments were conducted to investigate the thermal behavior, mechanical properties of composite solder alloys, shear fracture behavior of solder joints were evaluated as well. The modification process was carried out on the MWCNTs using electroless modification method to synthesis the Ni modified carbon nanotubes (Ni-CNTs), which was manually mixed into SAC305 solder powder with different amount. The melting point of the composite solder alloys was slightly increased with the increment of the amount of Ni-CNTs. The nanoindentation test results confirmed that the hardness and modulus of composite solder alloys were enhanced after the addition of Ni-CNTs. The aging experiment was implemented for the joints and the results indicated that the Ni-CNTs could effectively inhibit the growth of IMC layer as an additive in SAC305 solder. The shear strength of SAC305-xNi-CNTs/Cu (x = 0, 0.1 and 0.2 wt.%) joints was reinforced with the increment of Ni-CNTs amount. Furthermore, the SAC305-0Ni-CNTs/Cu and SAC305-0.1Ni-CNTs/Cu solder joints were broken partially between the solder and IMC, mostly between the solder matrix, and SAC305-0.2Ni-CNTs/Cu solder joint was broken completely inside solder matrix. It was suggested that the fracture mode of the solder joints changed from mix fracture mode to ductile fracture mode as the amount of Ni-CNTs increased.

中文翻译：

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Ni改性多壁碳纳米管对Sn-3.0Ag-0.5Cu复合焊点微观结构演变和剪切强度的影响

摘要 在Sn-3.0Ag-0.5Cu（SAC305）焊料中加入不同量的Ni改性多壁碳纳米管（MWCNTs）制备复合焊料。进行了实验以研究复合焊料合金的热行为、机械性能以及焊点的剪切断裂行为。采用化学改性方法对MWCNTs进行改性，合成Ni改性碳纳米管（Ni-CNTs），人工将其混入不同量的SAC305焊粉中。随着Ni-CNTs用量的增加，复合焊料合金的熔点略有升高。纳米压痕测试结果证实，添加Ni-CNTs后复合焊料合金的硬度和模量均有所提高。对接头进行了老化实验，结果表明，Ni-CNTs 作为 SAC305 焊料中的添加剂可以有效抑制 IMC 层的生长。SAC305-xNi-CNTs/Cu (x = 0、0.1 和 0.2 wt.%) 接头的剪切强度随着 Ni-CNTs 数量的增加而增强。此外，SAC305-0Ni-CNTs/Cu和SAC305-0.1Ni-CNTs/Cu焊点在焊料和IMC之间部分断裂，主要在焊料基体之间，SAC305-0.2Ni-CNTs/Cu焊点完全断裂内部焊料矩阵。这表明随着Ni-CNTs数量的增加，焊点的断裂模式从混合断裂模式转变为韧性断裂模式。SAC305-xNi-CNTs/Cu (x = 0、0.1 和 0.2 wt.%) 接头的剪切强度随着 Ni-CNTs 数量的增加而增强。此外，SAC305-0Ni-CNTs/Cu和SAC305-0.1Ni-CNTs/Cu焊点在焊料和IMC之间部分断裂，主要在焊料基体之间，SAC305-0.2Ni-CNTs/Cu焊点完全断裂内部焊料矩阵。这表明随着Ni-CNTs数量的增加，焊点的断裂模式从混合断裂模式转变为韧性断裂模式。SAC305-xNi-CNTs/Cu (x = 0、0.1 和 0.2 wt.%) 接头的剪切强度随着 Ni-CNTs 数量的增加而增强。此外，SAC305-0Ni-CNTs/Cu和SAC305-0.1Ni-CNTs/Cu焊点在焊料和IMC之间部分断裂，主要在焊料基体之间，SAC305-0.2Ni-CNTs/Cu焊点完全断裂内部焊料矩阵。这表明随着Ni-CNTs数量的增加，焊点的断裂模式从混合断裂模式转变为韧性断裂模式。2Ni-CNTs/Cu 焊点在焊料基体内部完全断裂。这表明随着Ni-CNTs数量的增加，焊点的断裂模式从混合断裂模式转变为韧性断裂模式。2Ni-CNTs/Cu 焊点在焊料基体内部完全断裂。这表明随着Ni-CNTs数量的增加，焊点的断裂模式从混合断裂模式转变为韧性断裂模式。