### Abstract

Creep data for a eutectic tin-silver alloy at temperatures between 298 K and 398 K have been analyzed using the modified theta-projection concept, instead of the steady-state creep constitutive equation in the following formula: ε_{cr} = A (1 - exp(-αt)} + B (exp(αt) - 1}, where A, B, and a are constants to be experimentally determined. The equation describes well the creep curves of the eutectic tin-silver alloy up to the tertiary stage. All constants exhibited power law relationships with the applied stress. The rate constant, α, has a high stress exponent, which is attributed to dispersion strengthening. The rate constant a and the strain factor B only showed temperature dependence, while the strain factor A was independent of temperature. The activation energy for α was 65 kJ/mol at high stresses and 90 kJ/mol at low stresses. The energies suggest that the dislocation pipe diffusion and the lattice diffusion are predominant at high stresses and low stresses, respectively.

Original language | English |
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Pages (from-to) | 1398-1402 |

Number of pages | 5 |

Journal | Journal of Electronic Materials |

Volume | 32 |

Issue number | 12 |

Publication status | Published - 2003 Dec |

Externally published | Yes |

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### Keywords

- θ projection
- Constitutive equation
- Creep
- Lead-free solder
- Nonsteady state
- Sn-3.5Ag

### ASJC Scopus subject areas

- Electrical and Electronic Engineering
- Electronic, Optical and Magnetic Materials
- Materials Science(all)
- Physics and Astronomy (miscellaneous)

### Cite this

*Journal of Electronic Materials*,

*32*(12), 1398-1402.