Diffusion bonding of aluminium alloy, 8090
- Lawrence Livermore National Lab., CA (United States)
Ability to diffusion bond aluminum (Al) alloys, in particular superplastic aluminum alloys, will complete the technology-base that is strongly needed to enhance the use of superplastic forming (SPF) technology. Diffusion bonding (DB) is an attractive manufacturing option for applications where the preservation of the base metal microstructure and, in turn, mechanical properties is important in the bond area. As the technology moves from the laboratory to production, the DB process has to be production-feasible and cost-effective. At the Lawrence Livermore National Laboratory, the DB study of SPF Al alloys has been initiated. This paper describes the effect of surface chemistry on the DB properties of the Al alloy, 8090 (2.4Li-1.18Cu-0.57Mg-0.14Zr-Al). The integrity of the diffusion bonds was evaluated for both interlayered and bare surfaces. Two interlayer elements, copper (Cu) and zinc (Zn), were compared. Although the eutectic temperature of Al-Cu is 548 C, a thin Cu layer in contact with 8090 has been shown to lower its eutectic temperature to [approximately]521 C. In 8090, Cu is one of the primary alloying elements but has a limited solubility in Al at the bonding temperature. Zinc, on the other hand, forms a considerably lower eutectic (380 C) with Al and is highly soluble in Al. The diffusivity of Zn in Al is much faster than that of Cu, but Zn forms a more thermodynamically stable oxide. These subtle metallurgical differences will affect the transient liquid phase (TLP) formation at the interface, which will subsequently influence the bond quality.
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 7105270
- Journal Information:
- Scripta Metallurgica et Materialia; (United States), Vol. 31:4; ISSN 0956-716X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ALUMINIUM BASE ALLOYS
BONDING
TENSILE PROPERTIES
COPPER ALLOYS
LITHIUM ALLOYS
DIFFUSION
EXPERIMENTAL DATA
ALLOYS
ALUMINIUM ALLOYS
DATA
FABRICATION
INFORMATION
JOINING
MECHANICAL PROPERTIES
NUMERICAL DATA
360101* - Metals & Alloys- Preparation & Fabrication
360103 - Metals & Alloys- Mechanical Properties