Although incremental sheet forming (ISF) is featured with greater flexibility, lower cost, and shorter leading time, there is less comprehensive sustainability assessment for ISF. In order to summarize the research progress on the sustainability evaluation of ISF and further explore its potential application scenario specifically, the research with respect to energy consumption and environmental impact of ISF are reviewed in this paper. First, the characteristics and research status of ISF including geometry accuracy improvement, forming force prediction, and heating-aided ISF are introduced. Then, study on the influence of processing parameters, equipment, and consumables on energy consumption (both deformation energy and machine tool energy) and forming efficiency are comprehensively reviewed. Current research indicates that neither deformation energy consumption nor electric energy consumption of ISF is lower than stamping process since ISF has long motion trajectory and forming time. In addition, the current methods (such as Life Cycle Assess method) to assess the environmental impact of ISF are discussed. Additionally, the environmental impact of ISF mainly reflects on sheet material, energy consumption, and lubrication oil. Moreover, the comparison of the ISF process and the other processes with regard to sustainability is analyzed, which indicates that ISF has obvious advantage and broad prospects when the cost of molds is considered and the batch size is generally less than 1000. The study provides valuable guidance on the further improvement of ISF towards more efficiency and green manufacturing process.

Sustainability assessment of incremental sheet forming: a review

Multi-stage Single-Point Incremental Forming: An Experimental Investigation of Surface Roughness and Forming Time

The present article describes a comprehensive literature review on multi-stage single point incremental forming (MSPIF). Multi-stage single point incremental forming is an advance metal forming process used to form sheet metal parts with steep wall angles. In MSPIF, overall deformation is distributed in intermediate stages. MSPIF provides better thickness distribution, geometrical accuracy and formability than single point incremental forming (SPIF) process. In the present literature review, research papers published during 2000–2021 are critically reviewed. Literature review is categorized in three major sections—geometrical accuracy, numerical simulation and surface roughness. Influence of various process parameters, forming conditions on responses, is studied and presented. Based on the literature review, future scope is also discussed. 

A Review on Multi-stage Incremental Sheet Forming

Single point incremental forming (SPIF) process is an advanced dieless sheet metal forming process in which the requirement of a dedicated punch-die setup is eliminated. The dedicated punch-die setup is replaced by a universal blank holding fixture, a punch (or tool), and a backing plate. It has a variety of applications ranging from automotive to biomedical fields. But its limitations such as inability to form steeper wall angle and high geometric error in single-stage restricts its application in sheet metal industries. To overcome this, multistage SPIF process is an alternative to achieve larger wall angles. Formability in multistage SPIF process is increased by providing intermediate stages. Various methodologies have been suggested to enhance the profile accuracy, however, it still remains the major issue. In the present paper influence of process variables namely feed rate, number of forming stages and pitch size on geometric accuracy and surface roughness of formed part is investigated. Taguchi L18 orthogonal array is used for design of the experiments. From the analysis of variance (ANOVA), it is found that the number of stages and pitch size have a significant influence on geometric accuracy and surface roughness. Since feed rate is an insignificant parameter. So a higher feed rate can be used to reduce forming time. Further, a mathematical model is developed to predict the geometrical accuracy and surface roughness of the formed part.

Sunandkumar Gajjar

Papers

Experimental Investigation on Geometric Accuracy and Surface Roughness of Formed Part in Multistage Single Point Incremental Forming (SPIF) Process