Hot Single Point Incremental Forming of Ti-6Al-4V Alloy

Abstract

The lightweight metal alloy Ti-6Al-4V is widely used in the aeronautical industry due to its excellent mechanical properties. However, it is known the difficulty to deform Ti-6Al-4V sheets at room temperature because of its microstructure conditions. The present work focuses on the evaluation of formability of Ti-6Al-4V sheets using hot single point incremental forming (SPIF) process which it seems appropriate to produce small batches of parts due to its flexibility as it allows a significant reduction of costs and lead times. In order to characterize the SPIF of Ti-6Al-4V under hot forming conditions, a set of forming trials evaluation tests was carried out. The obtained results have allowed identifying the key process features and have demonstrated the potential of the proposed approach to hot form of small amounts of Ti-6Al-4V parts.

Investigation of Thermal-Related Effects in Hot SPIF of Ti–6Al–4V Alloy

“…Furthermore, the titanium surface is embrittled by oxygen above 540 ºC as a function of time and temperature. 4 These temperature results match well with the material behaviour observed by Ortiz et al 27 where it was concluded that the formability of Ti-6Al-4V starts enhancing drastically from 500 ºC approximately. In spite of having the more homogenous temperature distribution, T1 trial finished before obtaining the final part since the sheet broke during the forming at the final stage.…”

“…In spite of having the more homogenous temperature distribution, T1 trial finished before obtaining the final part since the sheet broke during the forming at the final stage. As we observe above, the temperatures reached on the sheet in this case are not high enough to enhance the material formability as the study of Ortiz et al 27 points out. In fact, in T1 temperature is around 400 ºC so the formability is similar to that obtained at room temperature.…”

“…In all SPIF trials, parts were produced at a 1000 mm/min feed rate and a 0.29 mm tool step down except in the bottom that a 0.5 mm tool step along the part surface was used. These parameters were defined taking into account the Ti-6Al-4V formability evaluation that previously had been carried out, 27 since this study showed that the maximum material formability, that is, the maximum wall angle was obtained employing this parameters combination. The heating up of the sheets was made following conditions H4 according to Table 1, whereas the cooling of the parts consisted on switching off both the furnace and the heater frame after the forming stage without unclamping the parts until complete cooling down of the part.…”

Accuracy and Surface Quality Improvements in the Manufacturing of Ti-6Al-4V Parts Using Hot Single Point Incremental Forming

“…Thus, the parts were produced at a 1000 mm/min feed rate and a 0.29 mm tool step down except at the bottom area where a 0.5 mm tool step over the part surface was used following a raster strategy. These process parameters were defined taking into account both the Ti-6Al-4V formability evaluation that previously had been carried out [14] and the part geometry. For all the trials, a ceramic wheel tool with a 11 mm forming radius and boron nitride as lubricant were chosen to provide adequate contact conditions during forming.…”

Theoretical and Experimental Analysis of a New Process for Forming Flanges on Hollow Parts

“…Incremental forming methods, apart from shaping hollow products, are also used in forming cylindrical sheet metal products/tubes. These technologies can be also used in the production of products made of hard-deforming materials, such as titanium alloys [14,15].…”