A comprehensive review on heat-assisted incremental sheet forming

Heat-assisted Incremental Sheet Forming (HA-ISF) is a viable forming technique that uses the heat-source to form the sheet materials incrementally and progressively. The hard-to-form sheet materials may be formed effectively using the HA-ISF method which are otherwise difficult to form at the room temperature. HA-ISF may enable the greater formability of the formed sheet-parts and reduce the required forming forces for fabricating the sheet components. These possibilities have motivated the researchers to explore various aspects of HA-ISF and the effects of process factors on the various outcomes. In this review article, various dimensions and methods of this emerging technique of sheet forming have been explored. Each method of HA-ISF has been studied against the hard-to-form materials to establish a trend on the outcome like forming force, surface roughness and formability. The capabilities of these methods of warm forming have also been discussed for the hard sheet materials along with the mechanisms of the obtained results. Results shows that the nature of materials and the mode of heating the sheet during the forming process can affect the formability, surface roughness and the required deforming loads effectively. An attempt has also been made by the authors for providing and establishing the criteria to estimate the deforming loads that are required to deform the sheet material by using the analytical and predictive modelling approach. Available analytical models show difficulty in the prediction of the input parameters for desired output parameters. While the development of numerical models is very time-consuming and has significant deviation in result for the upper range of input parameters due to variation in material properties with varying temperature. Whereas, empirical modelling can be a viable approach to predict the HA-ISF process. In addition, various applications of the HA-ISF have also been discussed for streamlining this novel technique for industries to produce customized products from hard-to-form materials. Results also shows that the HA-ISF process is efficient for increasing the formability of hard sheet materials and for reducing the required deforming loads. Achieving the better dimensional accuracy and good surface finish is still the challenge in HA-ISF and researchers may focus on these areas for enhancing the capability of this technique of warm forming.