Diffusion welding of silver interlayers coated onto base metals by planar-magnetron sputtering

Journal Article · Mon Jan 01 00:00:00 EST 1990 · Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (USA)

DOI:https://doi.org/10.1116/1.577064· OSTI ID:6986125

Rosen, R S; Kassner, M E ^[1]

---

1. Lawrence Livermore National Laboratory, Livermore, California 94550 (US)

Silver has been coated onto various base metals by planar-magnetron (PM) sputtering to provide interlayers for diffusion welding. The vacuum-coating process consisted of two stages: (1) sputter etching of the base metals to remove surface oxide layers, followed by (2) vapor deposition of high-purity silver onto the clean surfaces. The silvers surfaces were diffusion welded at elevated pressure (207 MPa) and temperatures (483--673 K). The structures of the diffusion-welded-silver interlayer and the as-deposited'' coatings were determined using optical metallography and electron microscopy. The as-deposited structure consists of fine columnar grains {similar to}0.25 {mu}m in diameter, perpendicular to the base-metal surface with the axes of the columns oriented along the (111) crystallographic direction. These grains contain a high density of growth twins {similar to}15 nm thick. The diffusion-welded-silver interlayer consists mostly of large recrystallized grains ({gt}1 mm in diameter) containing a high density of annealing twins. However, a significant amount of the interlayer has not recrystallized. Additionally, the diffusion-welded-silver (silver-silver) interface consists of a high-angle grain boundary often formed between recrystallized and nonrecrystallized regions. For various base metals, the tensile strengths of diffusion-welded-silver joints fabricated using PM sputter deposition were found to be equal to or greater than previously reported strengths for those fabricated using brazing, electroplating, or other vapor-deposition methods. Tensile properties of diffusion-welded-silver joints fabricated using PM sputter-deposition were also found to be more reproducible than properties previously reported for joints fabricated using hot-hollow cathode (HHC) evaporation.

• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6986125
• Journal Information: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (USA), Vol. 8:1; ISSN 0734-2101
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
SILVER
DIFFUSION WELDING
VAPOR DEPOSITED COATINGS
BRAZING
ELECTROPLATING
ETCHING
HIGH TEMPERATURE
MAGNETRONS
METALLOGRAPHY
RECRYSTALLIZATION
SPUTTERING
TRANSMISSION ELECTRON MICROSCOPY
VACUUM EVAPORATION
VACUUM SYSTEMS
COATINGS
DEPOSITION
ELECTRODEPOSITION
ELECTROLYSIS
ELECTRON MICROSCOPY
ELECTRON TUBES
ELECTRONIC EQUIPMENT
ELEMENTS
EQUIPMENT
EVAPORATION
FABRICATION
JOINING
LYSIS
METALS
MICROSCOPY
MICROWAVE EQUIPMENT
MICROWAVE TUBES
PHASE TRANSFORMATIONS
PLATING
SURFACE COATING
SURFACE FINISHING
TRANSITION ELEMENTS
WELDING
360601* - Other Materials- Preparation & Manufacture