4. Conclusions
The effects of 0.06Ni and 0.5Sb additives on the microstructure and solidification behavior of Sn–1.0Ag–0.5Cu alloys (SAC105) as well as the creep properties have been investigated. Significant conclusions obtained in this research are as follows:
(1)
The addition of Sb to SAC(105) alloy suppresses the formation of large β-Sn grains and large needle-like precipitates and instead favors the formation of small β-Sn dendrites surrounded by fine eutectic regions of β-Sn, Ag3Sn and Cu6Sn5 IMC phases.
(2)
The addition of Ni favors the formation of fiber-like IMCs and finer dot-shaped precipitates on the surface of β-Sn matrix rather than needle-like morphology.
(3)
Alloying of Ni and Sb resulted in considerably reduced the undercooling and slightly decreased the pasty range, while elevated the melting temperature less than 1.5 oC.
(4)
With the addition of Ni and Sb into SAC105, significant improvement in creep resistance of (210%) and (350%) is realized when compared with the SAC105 solder alloy The SAC(105) 0.5Sb solder alloy had better creep property.
(5)
The creep life time of SAC105 alloys was remarkably enhanced 3 times with the 0.5Sb alloying additions.
(6)
According to the obtained stress exponents and activation energies, it is proposed that the dominant deformation mechanism in SAC(105) solders is dislocation climb over the whole temperature range investigated.