Mechanical behavior and microstructure of Au-Ni brazes
- Oregon State Univ., Corvallis, OR (United States)
- Univ. Ancona (Italy). Dept. of Mechanics
- Lawrence Livermore National Lab., CA (United States)
Thin Au-Ni alloy (57.5 at. pct Au and 42.5 at. pct Ni) interlayer brazes between strong base metals were found to have very high ultimate tensile strengths (UTSs) as a result of the triaxial stress state within the braze (reducing the effective, or von Mises, stress) and the high strength of the braze alloy. This high strength can be rationalized by the observed very refined two v phase microstructure. The yield strength and quasi-steady-state flow stress of the braze alloy was found to be relatively strain-rate insensitive. These results explain the absence of time-dependent, or delayed, tensile failures that have been observed in other braze interlayers. The fracture process appears to be one of cavity nucleation by microplasticity, followed by cavity coalescence or impingement once the required nuclei density is achieved. Substantial cavity growth does not appear to occur. This failure process contrasts with that of other interlayer metals, in which the failure mechanism appears to be unstable cavity growth.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 42866
- Journal Information:
- Metallurgical Transactions, A, Vol. 26, Issue 4; Other Information: PBD: Apr 1995
- Country of Publication:
- United States
- Language:
- English
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