Effect of stress relieving heat treatment on surface topography and dimensional accuracy of incrementally formed grade 1 titanium sheet parts

Behera, Amar Kumar; Ou, Hengan

Abstract

The forming of parts with an optimized surface roughness and high dimensional accuracy is important in many applications of incremental sheet forming (ISF). To realize this, the effect of stress relieving heat treatment of grade-1 Ti parts performed before and after forming on the surface finish and dimensional accuracy was studied. It was found that heat treatment at a temperature of 540 °C for 2 h improves the surface finish of formed parts resulting in a surface with little or no visible tool marks. Additionally, it improves the dimensional accuracy of parts after unclamping from the rig used for forming, in particular, that of parts with shallow wall angles (typically <25°). It was also noted that post-forming heat treatment improves the surface finish of parts. The surface topography of formed parts was studied using interferometry to yield areal surface roughness parameters and subsequently using secondary electron imaging. Back-scatter electron microscopy imaging results coupled with energy-dispersive X-ray (EDX) analysis showed that heat treatment prior to forming leads to tool wear as indicated by the presence of Fe in samples. Furthermore, post-forming heat treatment prevents curling up of formed parts due to compressive stresses if the formed part is trimmed.

Citation

Behera, A. K., & Ou, H. (2016). Effect of stress relieving heat treatment on surface topography and dimensional accuracy of incrementally formed grade 1 titanium sheet parts. International Journal of Advanced Manufacturing Technology, 87(9), https://doi.org/10.1007/s00170-016-8610-8

• Journal Article Type: Article
• Acceptance Date: Mar 4, 2016
• Online Publication Date: Apr 12, 2016
• Publication Date: Dec 31, 2016
• Deposit Date: May 19, 2017
• Publicly Available Date: May 19, 2017
• Journal: International Journal of Advanced Manufacturing Technology
• Print ISSN: 0268-3768
• Electronic ISSN: 1433-3015
• Publisher: Springer Verlag
• Peer Reviewed: Peer Reviewed
• Volume: 87
• Issue: 9
• DOI: https://doi.org/10.1007/s00170-016-8610-8
• Keywords: Stress relieving, Heat treatment, Titanium, Incremental sheet forming, Surface roughness, Trimming
• Public URL: https://nottingham-repository.worktribe.com/output/831098
• Publisher URL: http://link.springer.com/article/10.1007/s00170-016-8610-8
• Contract Date: May 19, 2017