The Measurement of Friction for Superplastic Forming of Ti-6Al-4V

Abstract

An experimental test for measuring the friction between Ti-6Al-4V sheet material and S310 stainless steel tool material at 900 o C is presented. The test is intended for application to Ti-6Al-4V superplastic forming for the manufacture of aeroengine components. The work is motivated by the need for accurate, representative data for process modelling, where accurate simulation is critical to formed component dimensions. The results show a time dependency of friction. The effects of boron nitride density, applied normal load and die surface roughness are investigated.All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of Trans Tech Publications Ltd, www.scientific.net. (Scite.

High-temperature lubricants for superplastic forming of metals

“…Differing amounts and types of solid lubricant, such as adjusting coating weight for graphite-based lubricants or percent content of BN for BN-based lubricants, can have a measurable infl uence on friction force. 10,11,12 Referring to Fig. 4.1 , a sheet with a low lubricant coating weight may split at the bottom corners due to excessive thinning; however, in some situations this may be prevented with an increase in lubricant thickness.…”

Finite element superplastic forming (FE‐SPF) of patient‐specific maxillofacial prostheses

“…Including friction in the simulation of SPF is a challenge since coefficients of friction are largely unknown and indeed likely to change during the process [20]. In practice, valuable information may be obtained from simulations assuming complete sticking or sliding contact between the forming sheet and the die.…”

“…The Ti-6Al-4V titanium alloy has a considerable number of applications in the manufacture of medical devices but it can be difficult to form because of its high strength, unless formed at relatively high temperature where it can either be hot worked or superplastically formed, in which case forming pressures are quite low, within the interval of [10][11][12][13][14][15][16][17][18][19][20] MPa. The relevant material 143 standard for Ti-6Al-4V alloy if the intended use is for surgical implants is BS 7252: Part 3: 1997 (ISO 5832-3: 1996).…”

Correlation of finite element analysis to superplastic forming experiments

“…Efforts to define the frictional behavior of the solid lubricants commonly applied in SPF have been conducted [19,20]; however, definitive correlation to simulation has not been established. Friedman et al [21] developed a high temperature sliding friction test apparatus that can be effectively used to screen solid lubricants used in SPF.…”