Research into the microstructure and mechanical behavior of eutectic Bi-Sn and In-Sn

Technical Report · Sun Aug 01 04:00:00 EDT 1993

DOI:https://doi.org/10.2172/10111223· OSTI ID:10111223

Goldstein, J L.F.; Mei, Z; Morris, Jr, J W ^[1]

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1. Lawrence Berkeley Lab., CA (United States)

This manuscript reports on research into two low-melting, lead-free solder alloys, eutectic Bi-Sn and eutectic In-Sn. The microstructures were found to depend on both cooling rate and substrate, with the greatest variability in the In-Sn alloy. The nature of the intermetallic layer formed at the solder-substrate interface depends on both the solder and the substrate (Cu versus Ni). Also, the microstructure of the Bi-Sn can recrystallize during deformation, which is not the case with In-Sn. Data from creep and constant strain rate tests are given for slowly cooled samples. The creep behavior of In-Sn is constant with temperature, but the creep seems to be controlled by the In-rich phase in In-Sn on Cu and by the Sn-rich phase in In-Sn on Ni. Bi-Sn exhibits different creep behavior at temperatures above 40 {degrees}C than at 20 {degrees}C or lower. Stress-strain curves of Bi-Sn on Cu and In-Sn on Cu are similar, while In-Sn on Ni behaves differently. This is explained in terms of the deformation patterns in the alloys.

• Research Organization: Lawrence Berkeley Lab., CA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 10111223
• Report Number(s): LBL--34793; CONF-9308103--1; ON: DE94004558
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102
360103
BISMUTH ALLOYS
CREEP
DEFORMATION
EUTECTICS
EXPERIMENTAL DATA
INDIUM ALLOYS
INTERFACES
INTERMETALLIC COMPOUNDS
MECHANICAL PROPERTIES
MELTING
MICROSTRUCTURE
PHASE DIAGRAMS
PHOTOMICROGRAPHY
STRAIN RATE
STRUCTURE AND PHASE STUDIES
TIN ALLOYS