Effect of adding 0.5wt% ZnO nanoparticles, temperature and strain rate on tensile properties of Sn–5.0wt% Sb–0.5wt% Cu (SSC505) lead free solder alloy (original) (raw)
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Sn-5 wt%Sb-0.5 wt%Cu (plain SSC505) and Sn-5 wt%Sb-0.5 wt%Cu-0.5 wt% ZnO (SSC-ZnO) composite solder alloys have been studied. The variation in thermal behavior, microstructure and tensile characteristics associated with mixing of 0.5 wt% ZnO nano-metric particles to plain SSC505 solder were investigated. A slight increment in the melting temperature [ΔT m ¼0.89 1C] was recorded using differential scanning calorimetry (DSC) after addition of ZnO. X-Ray diffraction (XRD) analysis confirmed the existence of β-Sn, SbSn and Cu 6 Sn 5 intermetallic compounds (IMCs) beside some of ZnO planes in SSC-ZnO composite solder. Field emission scanning electronic microscope (FE-SEM) investigation of SSC-ZnO composite solder revealed a homogenous uniform distribution, size refinement of IMCs and β-Sn grains. Addition of ZnO nano-metric particles into the plain SSC505 enhanced the yield stress σ YS by $ 12% and improved the ultimate tensile strength σ UTS by $ 13%. In addition, adding ZnO nano-metric particles was found to be effective for reducing ductility by $ 43% of the plain solder due to the refinement of β-Sn grains within SSC-ZnO composite solder.
Materials Science and Engineering: A, 2014
In the present study, nano-sized ZnO particle-reinforced Sn-3.0Ag-0.5Cu (SAC305) composite solder was prepared by mechanically dispersing nano-particles into SAC305 solder at 900 1C for 2 h. The effects of ZnO addition on microstructure, melting behavior and corresponding mechanical properties of SAC305 solder were explored. Microstructure analysis revealed that the wurtzite ZnO particles were effective in reducing both the β-Sn grain size and spacing between Ag 3 Sn and Cu 6 Sn 5 particles. The refined microstructure, which resulted in a strong adsorption effect and high surface-free energy of ZnO nanoparticles, could obstruct the dislocation slipping, and thus provides classical dispersion strengthening mechanism. This apparently enhances the yield stress (0.2%YS) and ultimate tensile strength (UTS) of SAC(305)-0.7%ZnO composite solder, whereas its ductility is lower than that of the SAC305 solder. In addition, ZnO particles keep the melting temperature of composite solder nearly at the SAC305 level although the pasty range is decreased. Empirical equations for 0.2% YS, UTS and elastic modulus E with the strain rate have been developed and the predicted tensile parameters for both solders are reasonably close to the present experimental data.
Journal of Materials Science: Materials in Electronics, 2013
Regarding to the development of Sn-Ag-Cu (SAC) lead-free solders for advance electronic components, the effect of 0.5 wt% nano-sized ZnO particles on the thermal, microstructure and tensile properties of Sn-3.5 wt% Ag-0.5 wt% Cu (SAC355) lead-free solder alloy is investigated. The results showed that addition of 0.5 wt% nano-sized ZnO particles into the conventional lead-free SAC355 solder caused a slight increase of its liquidus temperature by about 1.1 K. Metallographic observations of SAC355-0.5 wt% ZnO (composite solder) revealed an obvious refinement in the microstructure compared with the SAC355 (non-composite) solder. Consequently, addition of nano sized-ZnO particles could improve the stress-strain characteristics proof stress (r y0.2 ) and ultimate strength (r UTS ). This was rendered to suppressing effect of ZnO on the coarsening of the intemetallic compounds (IMCs) Ag 3 Sn and Cu 6 Sn 5 during the solidification process in the composite solder and subsequently dispersion strengthening is considered to be the dominating mechanism. This will allow the use of SAC355 composite lead-free solder alloy, to be consistent with the conditions of usage for conventional SAC solder alloys and to overcome the serious problem of the excessive growth of IMCs and the formation of microvoids in the SAC lead-free solder alloys.
The effects of Zn addition on the microstructure, thermal behavior and tensile creep properties of Sn–1.0Ag–0.3Cu (SAC103) alloy were systematically investigated. Differential scanning calorimetry (DSC) reveals that the reductions of undercooling and pasty range are more significant for Zn-containing solders, although the solidus temperature remains the same or slightly changed. The creep life time of plain SAC103 alloy was remarkably enhanced two times with the addition of 3 wt% Zn. Moreover, significant improvement in creep resistance of 145% and 360% is realized with the addition of 2 wt% and 3 wt% Zn into SAC(103) solder, respectively. The improvement of creep behavior is due to the microstructural change of Zn-containing solders, since the formation of new (Cu,Ag) 5 Zn 8 intermetallic compound (IMC) phase and fine fiber-like Ag 3 Sn precipitates at the surface of β-Sn matrix could provide more obstacles for dislocation pileup , which enhanced the stress exponent values and improved the creep resistance and creep life time. These results show that the Garofalo model is suitable for describing the steady-state creep behavior of SAC(103) solders over the tested stress and temperature ranges.
A B S T R A C T Eutectic Sn-Zn alloy is considered as one of the best lead free solder alloys in microelectronic industry. That motivates our group to select different weight percentage of Antimony (Sb) (0.5, 1.0, and 1.5 wt%) as an alloying to Sn-9.0Zn-0.5 Al solder alloy. The thermal behavior, microstructure modification as well as tensile properties of the new developed solder alloys were investigated. A slight increment of the melting temperature (∼ 1 °C) was recorded using differential scanning calorimetry (DSC) after additions of Sb. For 1.5 wt% of Sb, two en-dothermic peaks at 200.8 °C and 201.5 °C were observed, which are assigned as hypoeutectic Sn-Zn composition. X-ray diffraction (XRD) measurements confirm the existence of β-Sn phase, α-Zn phase, and Sb-Sn intermetallic compounds (IMCs). Scanning electron microscope (SEM) images indicate that the Sb additives refine the mi-crostructure and form a uniform distribution of IMCs in the matrix of solder. The road-like α-Zn phase, Al 6 Zn 3 Sn and SbSn IMCs were clearly appeared in β-Sn matrix, which are responsible of the enhancement in tensile strength. Moreover, α-Zn phases in the Sn-9Zn-0.5Al-1.5Sb alloy were modified as needle-like, broken enormously , depleted, and circle shapes. Generally, The Sb-containing alloys have higher ultimate tensile strength (UTS) and lower elongation than Sb-free solder alloy due to the solid solution and second phase dispersion strengthening effect. The relationship between UTS and temperature follow the Arrhenius law. The average activation energies (Q) were found to be 44.4 ± 1.0 kJ/mol, and the average stress exponents (n) were usually around 5.3 ± 0.45, which are close to pipe diffusion controlled creep in β-Sn matrix.
Journal of Alloys and Compounds, 2011
The near peritectic Sn-5Sb Pb-free solder alloy has received considerable attention for high temperature electronic applications, especially on step soldering technology, flip-chip connection. In the present study, a separate addition of the same amount of Ag and Cu are added with the near-peritectic Sn-5Sb solder alloy to investigate the effect of a third element addition on the microstructural, thermal and mechanical properties of the newly developed ternary solder alloys. The results indicate that the melting point of Sn-5Sb solder is enhanced by Ag and Cu additions. Besides, the Ag and Cu content refine the microstructure and form new intermetallic compounds (IMCs) with the near-peritectic Sn-5Sb solder alloy. The tensile tests revealed that all alloys exhibit higher mechanical strength with increasing strain rate and/or decreasing testing temperature, suggesting that the tensile behavior of the three alloys is strain rate and temperature dependence. The yield and ultimate tensile strength are higher for Sn-5Sb-0.7Cu alloy compared with Sn-5Sb and Sn-5Sb-0.7Ag alloys. Good mechanical performance of Sn-5Sb-0.7Cu solder is often correlated to a fine -Sn grain size and more dispersed Cu-Sn IMC particles, which makes the solder exhibit high strength and yield stress.
Materials Science and Engineering: A, 2010
In the present study, the effects of separate and dual addition of small amount of Ag and Cu on the microstructure and mechanical properties of the eutectic Sn-9Zn solder alloy were investigated. Results indicate that alloying of Ag and/or Cu resulted in refine the coarse needle-like Zn-rich phase and formation of intermetallic compounds (IMCs) with the eutectic solder. Single addition of Ag led to formation of AgZn, Ag 5 Zn 8 and -AgZn 3 IMCs, which results in significant increase in both ultimate tensile strength (UTS) and ductility, while, the flower shaped and rod shaped Cu 6 Sn 5, ␥-Cu 5 Zn 8 and -CuZn 5 IMCs produced by Cu alloying, results in small increase in UTS and ductility. The dual addition of Ag and Cu suppressed the appearance of Ag 5 Zn 8 IMCs due to the competition for Zn between Cu and Ag, which results in slight decrease in UTS and ductility of Sn-9Zn-1.5Ag solder. Worthy of notice is that all alloys demonstrated an increase in both UTS and yield stress with increasing strain rate and/or decreasing testing temperature, indicating that the tensile behavior of the four alloys often exhibits a strain rate and temperature dependence.
Arab Journal of Nuclear Sciences and Applications, 2018
The advantage of lead-liberated welding is the melting point of SnAg -Cu (SAC) alloys in the Sn-rich alloy. Nanoparticles welding which requires lowering melting point near the Sn-Pb eutectic point is getting a growing interest. Recently, the phase persistence of nanoparticles has been the project of massiveness of academic and experiential investigations. In this study, graphene nanoparticles (GNPa) with 0.3 percentages wt. % were successfully added into Sn-3.5Ag-0.7Cu lead-free solder. The effects of graphene nanoparticles (GNPa) on the microstructure, tensile properties, wettability, corrosion resistance, and hardness were subsequently investigated. The results show that graphene nanoparticles (GNPa) refine the microstructure with different features and enhance the wettability efficiently. Stressstrain tests show that the combined solder containing 0.3 wt graphene nanoparticles (GNPa) exhibits about 15% and 25% enhancement in tensile strength and hardness, respectively. In addition, the total elongation of Sn-3.5Ag-0.7Cu is 22% greater than that of the pure Sn-3.5Ag-0.7Cu-0.3GO solder alloy. The enhancing mechanism of 0.3GO on the achievement of combined samples is also studied. Stress strain experiments were inspected under different five strain rates ranging from 5.4x10-5 S-1 to 2.9x10-3 S-1 and different five temperatures extended from R.T. (298K) to 383 K for two alloys. The activation enthalpy suggests that the dominant mechanism is the grain bounding diffusion (GBD). Also, X-ray diffraction examination display the permanence of both β-Sn rich phase and the intermetallic compound Ag 3 Sn and very little particles or residue from the intermetallic composition γ-In Sn 4 .
— Sn-Zn alloy has been taken as one of the most important lead free solder alloys due to the toxicity and the alpha radiation of lead impurities. The influence of cooling rate on the mechanical and structural properties of Sn – 8.6 wt. % Zn lead free solder alloy was studied. The microstructure of the quenched and slowly cooled samples of Sn – Zn alloy was examined by X – rays analysis and Scanning electron microscopy (SEM). There is an appearance of fibrous type striated deformations on the surfaces of the quenched samples more than those on the surfaces of the slowly cooled samples. The hardening parameters were obtained through stress-strain relations in the temperature range 333-393K for slowly cooled and quenched samples. The quenching samples indicated an improvement in the mechanical properties. The energy activated the rate controlling mechanisms has been calculated and found to be 17.85 and 24.57 kJ/mol for slowly cooled and quenched samples respectively. These values were found to be close to those reported for the grain boundary sliding mechanism in Sn-based alloys.
Effect of Sb addition on the tensile deformation behavior of lead-free Sn–3.5Ag solder alloy
Materials & Design, 2011
The advantage of lead-liberated welding is the melting point of SnAg -Cu (SAC) alloys in the Sn-rich alloy. Nanoparticles welding which requires lowering melting point near the Sn-Pb eutectic point is getting a growing interest. Recently, the phase persistence of nanoparticles has been the project of massiveness of academic and experiential investigations. In this study, graphene nanoparticles (GNPa) with 0.3 percentages wt. % were successfully added into Sn-3.5Ag-0.7Cu lead-free solder. The effects of graphene nanoparticles (GNPa) on the microstructure, tensile properties, wettability, corrosion resistance, and hardness were subsequently investigated. The results show that graphene nanoparticles (GNPa) refine the microstructure with different features and enhance the wettability efficiently. Stressstrain tests show that the combined solder containing 0.3 wt graphene nanoparticles (GNPa) exhibits about 15% and 25% enhancement in tensile strength and hardness, respectively. In addition, the total elongation of Sn-3.5Ag-0.7Cu is 22% greater than that of the pure Sn-3.5Ag-0.7Cu-0.3GO solder alloy. The enhancing mechanism of 0.3GO on the achievement of combined samples is also studied. Stress strain experiments were inspected under different five strain rates ranging from 5.4x10-5 S-1 to 2.9x10-3 S-1 and different five temperatures extended from R.T. (298K) to 383 K for two alloys. The activation enthalpy suggests that the dominant mechanism is the grain bounding diffusion (GBD). Also, X-ray diffraction examination display the permanence of both β-Sn rich phase and the intermetallic compound Ag 3 Sn and very little particles or residue from the intermetallic composition γ-In Sn 4 .