A method for the systematic assessment of lubricant performance during superplastic sheet forming: Verfahren zur systematischen Bewertung der Schmierstoffleistung bei der superplastischen Blechumformung. Issue 10 (19th October 2017)

• Record Type: Journal Article
• Authors: Farrell, M.; Drabek, M.; Qarni, M.J.
• Is Part Of: Materialwissenschaft und Werkstofftechnik. Volume 48:Issue 10(2017)
• Page Start: 976
• Page End: 982
• Publication Date: 2017-10-19
• Subjects: Superplastic forming -- Ti-6Al-4 V -- coatings -- lubrication -- friction -- tribology; Superplastische Formgebung -- Ti-6Al-4 V -- Beschichtungen -- Schmierung -- Reibung -- Tribologie; Materials -- Periodicals; Materials -- Testing -- Periodicals; 620.1
• DOI: 10.1002/mawe.201700041
• Languages: English
• ISSNs: 0933-5137

Abstract

Abstract: Frictional forces at the die‐sheet interface during superplastic forming play an important role in controlling material flow. As such, lubricious coatings are routinely used to facilitate a low friction flow of sheet metal into the die cavity. They may also act as parting agents and/or oxidation barriers. The selection of coatings for the superplastic forming of Ti‐6Al‐4 V is limited by the requirement of thermomechanical stability at the high forming temperature, therefore, solid film coatings such as boron nitride are a common choice. However, little work has been published on coating performance during superplastic forming, particularly under true process conditions. This paper presents a method for the systematic assessment of superplastic forming coating performance by using a multi‐pocket die, which allows many coating types and combinations to be tested simultaneously during a single forming cycle. Sixteen coating combinations were evaluated in total and the resultant sheet thickness distributions compared, serving as an indicator of friction.