Electric hot incremental sheet forming of Ti-6Al-4V titanium, AA6061 aluminum, and DC01 steel sheets

Abstract

Single point incremental forming (SPIF) is an emerging forming process for rapid prototyping and manufacturing of complex components from sheet metals. Recently, the use of electric current for the local resistance heating of the deformation area has attracted much attention in SPIF. In order to further study the electric hot incremental sheet forming (EHISF), in the present research, the effect of utilizing various lubricants on the formability of Ti-6Al-4V, AA6061, and DC01 sheet metals is experimentally investigated by forming a truncated cone under different feed rates, vertical pitches, and electric currents. To this end, the Taguchi design of experiment (DOE) and the analysis of variance (ANOVA) are employed. The results showed that the formability of Ti-6Al-4V and AA6061 sheets can be improved using the EHISF. For both the sheets, the lubricant and the electric current have significant effects on the maximum achievable forming depth. In addition, the formability of the DC01 sheet is highly affected by the lubricant and the feed rate. The results of the DC01 sheet showed that at the considered wall angle, the maximum forming depth in the EHISF does not change, compared to the cold SPIF, but the thickness distribution of the formed part at a higher temperature is more uniform.