Superplastic Forming/Adhesive Bonding of Aluminum (Spf/Ab) Multi-Sheet Structures

Superplastic Forming/Adhesive Bonding of Aluminum (Spf/Ab) Multi-Sheet Structures

Author: National Aeronautics and Space Administration (NASA)

Publisher: Createspace Independent Publishing Platform

Published: 2018-06-20

Total Pages: 28

ISBN-13: 9781721573639

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A significant fraction of airframe structure consists of stiffened panels that are costly and difficult to fabricate. This program explored a potentially lower-cost processing route for producing such panels. The alternative process sought to apply concurrent superplastic forming and adhesive bonding of aluminum alloy sheets. Processing conditions were chosen to balance adequate superplasticity of the alloy with thermal stability of the adhesive. As a first objective, an air-quenchable, superplastic aluminum-lithium alloy and a low-volatile content, low-viscosity adhesive with compatible forming/curing cycles were identified. A four-sheet forming pack was assembled which consisted of a welded two-sheet core separated from the face sheets by a layer of adhesive. Despite some preliminary success, of over 30 forming trials none was completely successful. The main problem was inadequate superplasticity in the heat-affected zones of the rib welds, which generally fractured prior to completion of the forming cycle. The welds are a necessary component in producing internal ribs by the 'four-sheet' process. Other challenges, such as surface preparation and adhesive bonding, were adequately solved. But without the larger issue of tearing at the weld locations, complex panel fabrication by SPF/AB does not appear viable. Wagner, John A. (Technical Monitor) and Will, Jeff D. and Cotton, James D. Langley Research Center NASA/CR-2003-212400, NAS 1.26:212400


Superplastic Forming/adhesive Bonding of Aluminum (SPF/AB) Multi-sheet Structures

Superplastic Forming/adhesive Bonding of Aluminum (SPF/AB) Multi-sheet Structures

Author: Jeff D. Will

Publisher:

Published: 2003

Total Pages: 12

ISBN-13:

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Significant fraction of airframe structure consists of stiffened panels that are costly and difficult to fabricate. This program explored a potentially lower-cost processing route for producing such panels. The alternative process sought to apply concurrent superplastic forming and adhesive bonding of aluminum alloy sheets. Processing conditions were chosen to balance adequate superplasticity of the alloy with thermal stability of the adhesive. As a first objective, an air-quenchable, superplastic aluminum-lithium alloy and a low-volatile content, low-viscosity adhesive with compatible forming/curing cycles were identified. A four-sheet forming pack was assembled which consisted of a welded two-sheet core separated from the face sheets by a layer of adhesive. Despite some preliminary success, of over 30 forming trials none was completely successful. The main problem was inadequate superplasticity in the heat-affected zones of the rib welds, which generally fractured prior to completion of the forming cycle.


Superplastic Forming of Advanced Metallic Materials

Superplastic Forming of Advanced Metallic Materials

Author: G Giuliano

Publisher: Elsevier

Published: 2011-06-27

Total Pages: 384

ISBN-13: 0857092774

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Ultra fine-grained metals can show exceptional ductility, known as superplasticity, during sheet forming. The higher ductility of superplastic metals makes it possible to form large and complex components in a single operation without joints or rivets. The result is less waste, lower weight and manufacturing costs, high precision and lack of residual stress associated with welding which makes components ideal for aerospace, automotive and other applications. Superplastic forming of advanced metallic materials summarises key recent research on this important process. Part one reviews types of superplastic metals, standards for superplastic forming, processes and equipment. Part two discusses ways of modelling superplastic forming processes whilst the final part of the book considers applications, including superplastic forming of titanium, aluminium and magnesium alloys. With its distinguished editor and international team of contributors, Superplastic forming of advanced metallic materials is a valuable reference for metallurgists and engineers in such sectors as aerospace and automotive engineering. Note: The Publishers wish to point out an error in the authorship of Chapter 3 which was originally listed as: G. Bernhart, Clément Ader Institute, France. The correct authorship is: G Bernhart, P. Lours, T. Cutard, V. Velay, Ecole des Mines Albi, France and F. Nazaret, Aurock, France. The Publishers apologise to the authors for this error. Reviews types of superplastic metals and standards for superplastic forming Discusses the modelling of superplastic forming, including mathematical and finite element modelling Examines various applications, including superplastic forming of titanium, aluminiun and magnesium alloys


Superplastic Forming and Diffusion Bonding of Rapidly Solidified, Dispersion Strengthened Aluminum Alloys for Elevated Temperature Structural Applicat

Superplastic Forming and Diffusion Bonding of Rapidly Solidified, Dispersion Strengthened Aluminum Alloys for Elevated Temperature Structural Applicat

Author: National Aeronautics and Space Adm Nasa

Publisher: Independently Published

Published: 2018-11-19

Total Pages: 160

ISBN-13: 9781731402776

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Rapidly solidified alloys, based upon the Al-Fe-V-Si system and designed for elevated temperature applications, were evaluated for superplasticity and diffusion bonding behavior. Alloys with 8, 16, 27, and 36 volume percent silicide dispersoids were produced; dispersoid condition was varied by rolling at 300, 400, and 500 C (572, 752, and 932 F). Superplastic behavior was evaluated at strain rates from 1 x 10(exp -6)/s to 8.5/s at elevated temperatures. The results indicate that there was a significant increase in elongation at higher strain rates and at temperatures above 600 C (1112 F). However, the exposure of the alloys to temperatures greater than 600 C (1112 F) resulted in the coarsening of the strengthening dispersoid and the degradation of mechanical properties. Diffusion bonding was possible using low gas pressure at temperatures greater than 600 C (1112 F) which also resulted in degraded properties. The bonding of Al-Fe-V-Si alloys to 7475 aluminum alloy was performed at 516 C (960 F) without significant degradation in microstructure. Bond strengths equal to 90 percent that of the base metal shear strength were achieved. The mechanical properties and microstructural characteristics of the alloys were investigated. Ting, E. Y. and Kennedy, J. R. ALUMINUM ALLOYS; DIFFUSION WELDING; DISPERSION STRENGTHENING; DISPERSIONS; FORMING TECHNIQUES; SOLIDIFICATION; SUPERPLASTIC FORMING; SUPERPLASTIC FORMING; SUPERPLASTICITY; DEGRADATION; ELONGATION; MECHANICAL PROPERTIES; MICROSTRUCTURE; SILICIDES; STRAIN RATE...


Manufacturing Technology for Aerospace Structural Materials

Manufacturing Technology for Aerospace Structural Materials

Author: Flake C Campbell Jr

Publisher: Elsevier

Published: 2011-08-31

Total Pages: 617

ISBN-13: 0080462359

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The rapidly-expanding aerospace industry is a prime developer and user of advanced metallic and composite materials in its many products. This book concentrates on the manufacturing technology necessary to fabricate and assemble these materials into useful and effective structural components. Detailed chapters are dedicated to each key metal or alloy used in the industry, including aluminum, magnesium, beryllium, titanium, high strength steels, and superalloys. In addition the book deals with composites, adhesive bonding and presents the essentials of structural assembly. This book will be an important resource for all those involved in aerospace design and construction, materials science and engineering, as well as for metallurgists and those working in related sectors such as the automotive and mass transport industries. Flake Campbell Jr has over thirty seven years experience in the aerospace industry and is currently Senior Technical Fellow at the Boeing Phantom Works in Missouri, USA. * All major aerospace structural materials covered: metals and composites* Focus on details of manufacture and use* Author has huge experience in aerospace industry* A must-have book for materials engineers, design and structural engineers, metallurgical engineers and manufacturers for the aerospace industry