Tin-based solder alloys

Creep of Sn-Pb. The creep behavior of tin-lead has been well investigated. One set of data to describe the deformation behavior of fully recrystallized Sn-Pb36-Ag2 (Eq 3) is given in Table 1 (Ref 1). 

As seen in Ref 1, the deformation behavior of solder is strongly dependent on the structme of the solder. Sn-Pb, as soldered, consists of large domains that recrystallize due to plastic deformation. This leads to a refinement of the tin phases and to a coarsening of the Pb phases. Once the Sn has recrystallized, enabling GBS, the material is much easier to deform, and creep rates are higher. 

Creep of Lead-Free Alloys. Parameters for the deformation of lead-free solder have been published (Ref 11, 12) but are not necessarily consistent with each other. A comprehensive set 

Another work (Ref 14) shows different values of creep rates for lead-free solder and Sn-Pb solder than Ref 13 but similar ratios of creep rates for lead-free solder and Sn-Pb solder (Table 3). 

Further measurements (Ref 15) with Sn-Ag3.8-Cu0.7 gave a comparison of the creep rates with Sn-Pb-Ag (Table 4). 

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