•Critical assessment of single point incremental forming for industrial implementation.•Systematic approaches to improvement in process limits tracked.•Approaches to part precision improvement ...identified.•Improvements in process simulation techniques classified.•Aspects of process design for sustainable manufacture highlighted.
The last decade has seen considerable interest in flexible forming processes. Among the upcoming flexible forming techniques, one that has captured a lot of interest is single point incremental forming (SPIF), where a flat sheet is incrementally deformed into a desired shape by the action of a tool that follows a defined toolpath conforming to the final part geometry. Research on SPIF in the last ten years has focused on defining the limits of this process, understanding the deformation mechanics and material behaviour and extending the process limits using various strategies. This paper captures the developments that have taken place over the last decade in academia and industry to highlight the current state of the art in this field. The use of different hardware platforms, forming mechanics, failure mechanism, estimation of forces, use of toolpath and tooling strategies, development of process planning tools, simulation of the process, aspects of sustainable manufacture and current and future applications are individually tracked to outline the current state of this process and provide a roadmap for future work on this process.
This reprint focuses on the forming technologies and mechanical properties of advanced materials. Plastic working is the most efficient and an important manufacturing technology in today's industry. ...Plastic working technologies enable giving the material the appropriate functional properties, which depend on the rheological conditions of the plastic forming process and on the thermoplastic treatments carried out during the forming process. Metal processing is one of the most important sectors of the economy. In addition to the continuous improvement in the existing methods of plastic working, new technologies are also implemented, the purpose of which is to reduce the energy consumption of processing and the modernization of technological machines and tools. The subjects of research articles published in this reprint are multidisciplinary, including friction and lubrication in sheet metal forming, the single-point incremental forming of polymeric and lightweight metallic sheets, the optimization of shear spinning parameters and the cutting performance of cutting tools, the numerical and experimental analysis of titanium sheet forming, the mechanical and structural properties of titanium alloy subjected to impact-oscillatory loading, macro- and microdeformation characteristics of Ti-2.5Al-1.5Mn foil, and the optimisation of the thermomechanical process of nickel-based oxide-dispersion-strengthened superalloys.
Forming a metallic sheet along with the consideration of computer simulation and experiment had benefited the milling industry for a long time. The ideal forming, without an error, is a concerning ...topic. So, the computer simulation had the advantage then direct forming. To observe the results before doing the real experiments simulation comes handy. Which helped to set the parameters for the milling process for the single point incremental forming (SPIF) process. For milling, a CAD design was converted into a 3D model. For this, a conical shape of 3D modeling was made in fusion 360. After onwards, it was simulated for finding the maximum depth for the cracking point. Next for the experimental part, the maximum forming depth was considered, and used lubricant grease for reducing friction. While forming with the grease, the impact of parameters was also changed. Throughout the process, an optimization approach was set to reduce the cracking areas for the G-code. Along with the lubricant use, smooth milling finished surface was observed. To reducing the depth forming errors, an optimization approach was introduced in this research.
Single Point Incremental Forming (SPIF), a numerically controlled sheet forming technique, excels in adaptability and cost reduction for small-scale production and customized parts. This study ...explores multi-stage SPIF, focusing on applications in the medical domain, particularly the fabrication of personalized medical implants. Addressing critical challenges related to formability and accuracy, this study emphasizes the significance of multi-stage forming and the importance of the design of intermediate shapes. Forming a cranial implant using one intermediate stage is studied, preliminary in pure Zinc as a cost-effective alternative for heated Ti. The intermediate shape is generated using automatic geometry adaptations such as translating and scaling the CAD model. Nine different experiments are conducted and compared in terms of final geometric accuracy and thickness distributions. The study shows that the proposed intermediate shapes for multi-stage forming significantly improve the geometric accuracy from 1.08 mm mean absolute deviation in traditional single stage forming to 0.41–0.59 mm. However, the used intermediate shapes have a strong but varying effect on thickness distributions throughout the part, showing the importance and sensitivity of the exact intermediate geometry. These insights provide a valuable understanding of the process, shaping the pathway for enhanced utilization of SPIF and setting the stage for future improvements.
Electric pulse assisted incremental sheet forming (E-ISF) has been proven to enhance the formability of Ti-6Al-4 V sheet. However, the high electro-thermal effect induced by electric pulse could ...result in severe surface oxidation and excessively coarse grains of the final parts. In this study, a water-cooling system was employed to fabricate high-quality Ti-6Al-4 V parts during electric pulse assisted incremental forming. The excellent surface finish of Ti-6Al-4 V parts fabricated using water-cooling system can be attributed to the low forming temperature. Additionally, the activated non-basal slip can lead to the texture transition from {0001} 〈01−10〉 to {11−20} 〈0001〉 texture, together with the dynamic recrystallization of α and β grains, resulting in forming heights larger than 15 mm. This study indicates that the water-cooling system is an effective strategy for achieving low surface roughness, high formability, and geometric accuracy in Ti-6Al-4 V parts during the electric pulse assisted incremental sheet forming.
Single point incremental forming is a flexible sheet forming process that does not require a dedicated punch and die for making products for various applications. However, forming parts at steep wall ...angles, closer to 90°, using this process poses difficulties due to excessive thinning. The motivation behind this study is to overcome the challenges associated with forming parts at steep wall angles using the single point incremental forming process. Controlling the thickness distribution is a significant challenge that needs to be addressed. Excessive thinning leads to disqualification of design criteria, thereby restricting the process’ industrial applicability. In the present work, an improved clamping mechanism along with a multi-stage forming approach is employed to address the issue of excessive thinning. Two strategies were evolved; in strategy 1, an improved clamping mechanism was developed for single stage single point incremental forming, while strategy 2 consists of the improved clamping strategy along with a multi-stage forming approach for a single point incremental forming process. The improved clamping was based on the deep drawing process’ blank holding type clamping mechanism in both these strategies. The study aimed to compare the formed components’ forming depth and thickness distribution using the two strategies. The result revealed that strategy 2 was more effective, resulting in better thickness distribution in the formed component. The thickness distribution improvement resulted from metal flow from the flange region, owing to the improved clamping strategy, during the single and multi-stage forming at steep wall angles.
Incremental Forming IF is a suitable sheet metal forming technique for producing complex forms by local deformation. The forming tool movement follows the designed tool path controlled by the CNC ...machine programme. The main categories of the process are single point, SP and two points, TP "with enhancement tools". Additionally, the product design determines the enhancement tool type used and its obstacles. The enhancement tools are used for improvement of the product profile quality, while maintaining the simplicity of the process. The material formability is affected by mechanical properties and characteristics of the product profile. The limits are concerning the forming tools used and the blank thickness. On the other hand, due to the difficult environment of these process models, numerical methodologies controlled by Finite Element Method, FEM are currently in extensive use. The research offers the main data and results of a comparing study on the influence of using the enhancement tools in IF through FEM. The study purposes to identify the scientific differences of the IF processes, "with and without enhancement tools" by evaluating the thickness and strains distribution of the deformed blank section. In addition, the analysis and the evaluation of the final product profile have been studied.
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