Effect of small additions of indium on transient and steady-state creep characteristics, microstructure and properties of Sn-9Zn lead-free solders

Abstract EN

Complete enforcement of the new propagation of lead-free solders needed detailed knowledge and comprehension of their mechanical attitude.

In the present study transient and steady-state creep tests, microstructure and characteristic of Sn-9Zn lead free solders and Sn-9Zn-2In ternary alloys were studied under different five applied stresses ranging from ranged from 3.62 to 11.22 MPa and in the temperature range from 323K to 403K.

It is obvious that the additions of Indium alloy to the Sn-9Zn binary system lead to a reducing of the melting point to, therefore, the Sn-9Z-2In solder material shows maximum ductility (strain) and well-behaved mechanical realization than that of eutectic Sn-9Zn commercial solder.

Microstructural analysis revealed that the ternary alloys are more fine and refining than binary due to existence of -InSn4.

The activation energy of transient creeps have been found to be 20.16 - 26.32 and 16.80 - 22.44 kJ mol−1 in the low and high temperature regions for Sn-9Zn binary and Sn-9Z-2In ternary alloys respectively.

The steady state creep was studied in the same temperature range under same loads.

The strain rate sensitivity parameter (m) has been found to elevate by elevating the applied temperature and stresses.

The activation energies of steady state creep of the alloy have been found to be 26.31-30.82 and 23.36 -27.13 kJ mol−1 in the low and high temperature regions for Sn-9Zn binary and Sn-9Z-2In ternary alloys, respectively.