Effect of friction and back pressure on the formability of superplastically formed aluminium alloy sheet

Research output: Contribution to conferencePaper

4 Citations (Scopus)

Abstract

This paper examines the effect of friction and back pressure on the formability of superplastically formed aluminium alloy AA7475 sheet at the temperature of 517 °C. Several experiments with lubrication and back pressure are performed using a simple box shape tool cavity. The coefficient of Coulomb friction between the formed sheet and tool has been determined indirectly using a finite element model to simulate superplastic forming of the box shape. Typical values determined for all lubricant conditions tested are in the range 0.1 < μ < 0.2. The void growth with strain was determined directly from measurements as a function of back pressure. The results show the application of back pressure at 1 MPa reduces the growth of voids from 7% to 0.3% void volume fraction at a logarithmic thickness strain of 0.65. This paper reports back pressure has a significantly greater role than friction in enhancing the formability of the alloy
LanguageEnglish
Pages532-539
Number of pages8
DOIs
Publication statusPublished - 28 Mar 2011
EventSheMet Conference 2011 - Leuven, Belgium
Duration: 17 Apr 201120 Apr 2011

Conference

ConferenceSheMet Conference 2011
CountryBelgium
CityLeuven
Period17/04/1120/04/11

Fingerprint

Formability
Aluminum alloys
Friction
Lubrication
Lubricants
Volume fraction
Experiments
Temperature

Keywords

  • aluminium alloy AA7475,
  • superplastic forming
  • lubrication,
  • friction coefficient
  • back pressure
  • finite element analysis
  • FEA

Cite this

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title = "Effect of friction and back pressure on the formability of superplastically formed aluminium alloy sheet",
abstract = "This paper examines the effect of friction and back pressure on the formability of superplastically formed aluminium alloy AA7475 sheet at the temperature of 517 °C. Several experiments with lubrication and back pressure are performed using a simple box shape tool cavity. The coefficient of Coulomb friction between the formed sheet and tool has been determined indirectly using a finite element model to simulate superplastic forming of the box shape. Typical values determined for all lubricant conditions tested are in the range 0.1 < μ < 0.2. The void growth with strain was determined directly from measurements as a function of back pressure. The results show the application of back pressure at 1 MPa reduces the growth of voids from 7{\%} to 0.3{\%} void volume fraction at a logarithmic thickness strain of 0.65. This paper reports back pressure has a significantly greater role than friction in enhancing the formability of the alloy",
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author = "Paul Wood and Qarni, {Muhammad Jawad} and Andrzej Rosochowski",
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note = "SheMet Conference 2011 ; Conference date: 17-04-2011 Through 20-04-2011",

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Effect of friction and back pressure on the formability of superplastically formed aluminium alloy sheet. / Wood, Paul; Qarni, Muhammad Jawad; Rosochowski, Andrzej.

2011. 532-539 Paper presented at SheMet Conference 2011, Leuven, Belgium.

Research output: Contribution to conferencePaper

TY - CONF

T1 - Effect of friction and back pressure on the formability of superplastically formed aluminium alloy sheet

AU - Wood, Paul

AU - Qarni, Muhammad Jawad

AU - Rosochowski, Andrzej

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N2 - This paper examines the effect of friction and back pressure on the formability of superplastically formed aluminium alloy AA7475 sheet at the temperature of 517 °C. Several experiments with lubrication and back pressure are performed using a simple box shape tool cavity. The coefficient of Coulomb friction between the formed sheet and tool has been determined indirectly using a finite element model to simulate superplastic forming of the box shape. Typical values determined for all lubricant conditions tested are in the range 0.1 < μ < 0.2. The void growth with strain was determined directly from measurements as a function of back pressure. The results show the application of back pressure at 1 MPa reduces the growth of voids from 7% to 0.3% void volume fraction at a logarithmic thickness strain of 0.65. This paper reports back pressure has a significantly greater role than friction in enhancing the formability of the alloy

AB - This paper examines the effect of friction and back pressure on the formability of superplastically formed aluminium alloy AA7475 sheet at the temperature of 517 °C. Several experiments with lubrication and back pressure are performed using a simple box shape tool cavity. The coefficient of Coulomb friction between the formed sheet and tool has been determined indirectly using a finite element model to simulate superplastic forming of the box shape. Typical values determined for all lubricant conditions tested are in the range 0.1 < μ < 0.2. The void growth with strain was determined directly from measurements as a function of back pressure. The results show the application of back pressure at 1 MPa reduces the growth of voids from 7% to 0.3% void volume fraction at a logarithmic thickness strain of 0.65. This paper reports back pressure has a significantly greater role than friction in enhancing the formability of the alloy

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KW - back pressure

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