Development of an interfacial heat transfer coefficient model for the hot and warm aluminium stamping processes under different initial blank temperature conditions
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
Different initial blank temperatures, or forming temperatures, are applied in hot and warm aluminium stamping processes depending on the component being formed and the desired post-form properties. An initial blank temperature dependent interfacial heat transfer coefficient is therefore an essential boundary condition in such non-isothermal forming processes for obtaining precise temperature fields from the formed components in finite element simulations. This precision is crucial for the optimisation of the processing window and tool design, to subsequently achieve the desired cooling rates and post-form strength of the aluminium components being formed. The IHTC between a 7075 aluminium alloy and tungsten carbide cobalt coated cast-iron was found to approximately increase linearly with increasing initial blank temperature in the present research. The effect of the initial blank temperature was identified as a combination of two mechanisms; the effects of material strength and thermal conductivity. The IHTC was found to decrease with increasing strength of the blank when the contact pressure was lower than a threshold value, while a larger thermal conductivity of the aluminium blank increased the IHTC values. Furthermore, an initial blank temperature-dependent model was developed to predict the IHTC at different initial blank temperatures, which was subsequently verified by the results of non-isothermal forming tests.
Date Issued
2019-11
Date Acceptance
2019-05-20
Citation
Journal of Materials Processing Technology, 2019, 273
ISSN
0924-0136
Publisher
Elsevier
Journal / Book Title
Journal of Materials Processing Technology
Volume
273
Copyright Statement
© 2019 Elsevier B.V. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/
Sponsor
CRRC Qingdao Sifang Co.,Ltd
Commission of the European Communities
Grant Number
MESM_P57419
723517
Subjects
0913 Mechanical Engineering
0912 Materials Engineering
0910 Manufacturing Engineering
Materials
Publication Status
Published
Article Number
116245
Date Publish Online
2019-05-21