Effect of Phase Transformation on Creep Characteristics of Sn—5 wt% Bi Alloy

Abstract

The creep characteristics of Sn—5 wt% Bi alloy have been investigated under different constant applied stresses ranging from 26.8 to 29.4 MPa and at different temperatures ranging from 305 to 373 K. Results of both transient and steady state creep indicated one transition point at 328 K. The transient creep parameters β and n were calculated and found to change with the applied stresses from 1.8 × 10−6 to 6.36 × 10−5 and from 0.53 to 0.98, respectively. The strain rate sensitivity parameter (m) was found to change from 0.071 to 0.093 which characterizes a dislocation mechanism. The activation energy of the transient creep amounted to 17 and 33 kJ/mol before and after the transformation temperature, due to both glide of dislocations and cross slipping dislocation mechanism, respectively. The activation energies of the steady state creep in the vicinity of the transformation and above the transformation temperature were found to be 62 and 87 kJ/mol as characteristic of the grain boundary sliding mechanism. The analysis of the X‐ray diffraction patterns of the alloy samples confirmed all the above‐mentioned mechanisms.

Study of Steady State Creep and Lattice Parameters of Sn–1 wt% Zn Pewter near the Transition Temperature

“…The strain rate sensitivity parameter m has values ranging from 0.138 to 0.211, that shows dislocations glide as operating mechanism in the whole temperature range (393 to 453 K) [2,10].…”

“…It has to some extent replaced the traditional silverware which was part of the domestic scene. The creep characteristics of an important pewter alloy (Sn±5 wt% Bi) have been investigated [2]. The values of the strain rate sensitivity parameter showed that the dominant mechanism was a dislocation one.…”

Effect of structure transformation on the creep characteristics of Sn–3wt% Bi alloy

“…The former value indicates that glide of dislocations occurs before the transition. After transition, the higher value of transient activation energy may be in a good agreement with the cross-slipping dislocation mechanism [8]. The average activation energies of the steady state creep (Fig.…”

“…Creep tests of Sn-5 wt% Bi revealed a decomposition of the alloy at 328 K into a solid solution and pure Bi. Both the strain rate sensitivity parameter changes and the values of the activation energy obtained before and after precipitation of the Bi phase were attributed to a grain boundary sliding mechanism [8]. A decrease in the steady state creep rate and an increase in the activation volume were obtained [9] with increasing grain size for Sn-0.5 at.% Bi alloy.…”

Vibration Fracture Behavior of Sn-Bi Solder Alloys with Various Bi Contents

“…Much work has focused on this alloy system. The properties such as wettability, 1,2) microstructural coarsening, 3,4) creep, [5][6][7][8] strain rate sensitivity 9) and fillet lifting 10,11) have been concerned and studied. Given that plastic deformation, even failure, may occur due to vibration when solder joints are assembled in automobile vehicles and aircraft, 12,13) in particular when the vibration frequency meets the resonant vibration of the structure, obviously, the vibration fracture resistance of the solder should be taken into consideration during alloy design.…”