Delayed mechanical failure of silver-interlayer diffusion bonds

Journal Article · Sat Dec 01 00:00:00 EST 1990 · Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States)

DOI:https://doi.org/10.1007/BF02647306· OSTI ID:6955975

Kassner, M E ^[1]; Rosen, R S; Henshall, G A ^[2]

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1. Oregon State Univ., Corvallis, OR (United States)
2. Lawrence Livermore National Lab., CA (United States). Physical Metallurgy and Joining Section

Silver-interlayer diffusion bonds were fabricated using planar-magnetron sputtering (PMS). The bonds exhibit very high tensile strengths, despite the soft interlayer, because of the constraint by the base metal. However, these joints undergo delayed failure at relatively low tensile stresses at ambient temperatures, apparently by a ductile microvoid coalescence mechanism at the bond interfaces. Two classes of delayed tensile failure were investigated. In the first case, the applied stress does not produced any plastic deformation in the base metal, and failure appears to be controlled by time-dependent plasticity within the silver interlayer as a result of the effective stress in the interlayer. The plasticity causes cavity nucleation and, eventually, interlinkage and failure. In the second case, time-dependent plasticity is observed in base metals, and concomitant shear occurs within the softer silver under a high triaxial stress state. Here, the time-dependent plasticity of the base metal accelerates plasticity and failure in the interlayer. These models were substantiated by careful analysis of the stress and temperature dependence of the rupture times, finite element analysis of the stress state within the interlayer, and microscopy of the fracture surfaces and interfaces loaded to various fractions of the expected rupture times. These findings are applicable to bonds in which the interlayers are prepared by processes other than physical vapor deposition.

• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6955975
• Journal Information: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States), Vol. 21; ISSN 0360-2133
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
MARAGING STEELS
VAPOR DEPOSITED COATINGS
SILVER
PHYSICAL VAPOR DEPOSITION
STAINLESS STEEL-304
WELDED JOINTS
FAILURE MODE ANALYSIS
ADHESION
CREEP
EXPERIMENTAL DATA
FILLER METALS
RUPTURES
SAMPLE PREPARATION
ALLOYS
AUSTENITIC STEELS
CHROMIUM ALLOYS
CHROMIUM-NICKEL STEELS
COATINGS
CORROSION RESISTANT ALLOYS
DATA
DEPOSITION
ELEMENTS
FAILURES
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
HIGH ALLOY STEELS
INFORMATION
IRON ALLOYS
IRON BASE ALLOYS
JOINTS
MARTENSITIC STEELS
MATERIALS
MECHANICAL PROPERTIES
METALS
NICKEL ALLOYS
NUMERICAL DATA
STAINLESS STEELS
STEEL-CR19NI10
STEELS
SURFACE COATING
SYSTEM FAILURE ANALYSIS
SYSTEMS ANALYSIS
TRANSITION ELEMENTS
360103* - Metals & Alloys- Mechanical Properties