**5. Conclusions**

This work presents the integration of the hammering operation with the incremental sheet forming process. The differences in terms of formability are investigated with the help of a VWATC test geometry. Further, the comparative experimental results of the CWATC investigate the geometrical aspects of both processes. It is observed that the introduction of the hammering effect during the ISF process imparts significant improvements, such as increased fracture depth, better surface roughness, and uniform thickness distribution, in the formed components. The concluding remarks based on the statistical analysis can be summarized as:


The results in terms of wall angle achieved and fracture depth show the percentage differences of less than 5%, but the variation in sheet thickness and surface roughness shows promising results with more than 5% differences. The indicative statistical analysis shows that the ISH process would lead to an overall 10.99% improvement in the quality of the parts, primarily in the surface finish and forming forces. Further, the experiments are performed with one set of hammering parameters; thus, the proper choice and optimization of process parameters is a subject of further extensive investigation.

**Author Contributions:** H.Y.S., A.K.D. and P.K. conducted the numerical modelling, performed experiments, and wrote the first draft of the manuscript; P.T., A.P. and H.Y. provided the concept; D.P. and A.P. provided the testing data for numerical simulation; P.T. edited the draft of the manuscript and designed the overall simulation and the experimentation. All authors have read and agreed to the published version of the manuscript.

**Funding:** The study was carried out within the framework of the implementation of the Resolution of the Government of the Russian Federation of 9 April 2010, No. 220 (Contract No. 075-15-2019-869 from 12 May 2019) and by a gran<sup>t</sup> of the Russian Science Foundation (project No. 20-69-46042 of 20 May 2020).

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** The data sets used or analyzed during the current study are available with the corresponding author upon reasonable request.

**Acknowledgments:** This research is supported by the Department of Science and Technology (DST), India (Project No.: INT/RUS/RFBR/P-349) and Russian Foundation for Basic Research (RFBR), Russia. The authors wish to acknowledge the funding agency of both countries.

**Conflicts of Interest:** The authors declare no conflict of interest.

**Figure A1.** Flowchart of the generalized python code for CWATC.
