Vikas Sisodia

Bio: Vikas Sisodia is an academic researcher from Sardar Vallabhbhai National Institute of Technology, Surat. The author has contributed to research in topics: Sheet metal & Surface roughness. The author has an hindex of 2, co-authored 9 publications receiving 11 citations.

Experimental study of single point incremental forming with dummy sheet

Abstract: The present article focuses on single point incremental forming (SPIF) process with dummy sheet. Influence of process parameters namely dummy sheet thickness, tool size, step size, wall angle and feed rate on minimum thickness of formed parts is investigated. After experimentation and analysis, it is found that the wall angle, tool size, dummy sheet thickness and step size are significant parameters. Based on the analysis mathematical model is developed to predict minimum thickness of formed part. Further optimisation of process parameters is performed using desirability function in order to maximize the minimum thickness. In SPIF process with dummy sheet, it is observed that the variation in wall thickness is small and overall wall thickness distribution along the depth of formed parts is almost uniform. Also, wall thickness distribution obtained is close to the value predicted by sine law.

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

Abstract: 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.

Hybrid Incremental Forming: Investigation on Localized Thinning and Thickness Distribution in Formed Parts

Abstract: In the present experimental work, hybrid incremental sheet forming (HISF) process comprising stretch forming followed by single point incremental sheet forming (SPIF) is developed for forming conical frustum. Experimental investigation is done to find the influence of process parameters on thickness distribution and localized thinning in the formed parts. Experimental result reveals that stretching has a substantial effect on localized thinning in formed parts. Small improvement in the thickness distribution and localized thinning is found in formed parts. Experimental investigation on the influence of preform tool shape is also done to further improve thickness distribution. It is observed that the geometry of preform tool and amount of stretching has a great influence on thinning and thickness distribution. It is found that intermediate preform tool size and small amount of preforming results in forming conical frustum having uniform thickness distribution. Also, a considerable reduction in forming time using developed HISF process is observed as compared to SPIF process alone.

Study of AA-1050 sheet metal parts processed by single point incremental forming with dummy sheet

Abstract: The present paper describes an experimental study of AA-1050 sheet metal part processed by single point incremental forming (SPIF) with dummy sheet. Influence of process parameters namely step-down size, tool size, feed rate, dummy sheet thickness and forming angle on surface roughness of formed part is investigated. From the analysis of results, it is observed that step-down size, tool size, dummy sheet thickness and forming angle are significant process parameter and feed rate is insignificant. Surface roughness decreases with increase in tool size, dummy sheet thickness and forming angle; while it increases with increase in step-down size. Based on experimentation and analysis of results, a mathematical model to predict surface roughness is developed. Further, optimisation is performed on the basis of desirability function to minimise surface roughness. Also, optimisation algorithm namely genetic algorithm and simulated annealing available in MATLAB optimisation tool box is applied to find out the optimum surface roughness. Experimental results are found to be in good agreement with results predicted by the developed mathematical model.

Surface Finish Analysis in Single Point Incremental Sheet Forming of Rib-Stiffened 2024-T3 and 7075-T6 Alclad Aluminium Alloy Panels

Abstract: The article presents the results of the analysis of the interactions between the single point incremental forming (SPIF) process parameters and the main roughness parameters of stiffened ribs fabricated in Alclad aluminium alloy panels. EN AW-7075-T6 and EN AW-2024-T3 Alclad aluminium alloy sheets were used as the research material. Panels with longitudinal ribs were produced with different values of incremental vertical step size and tool rotational speed. Alclad is formed of high-purity aluminium surface layers metallurgically bonded to aluminium alloy core material. The quality of the surface roughness and unbroken Alclad are key problems in SPIF of Alclad sheets destined for aerospace applications. The interactions between the SPIF process parameters and the main roughness parameters of the stiffened ribs were determined. The influence of forming parameters on average roughness Sa and the 10-point peak–valley surface roughness Sz was determined using artificial neural networks. The greater the value of the incremental vertical step size, the more prominent the ridges found in the inner surface of stiffened ribs, especially in the case of both Alclad aluminium alloy sheets. The predictive models of ANNs for the Sa and the Sz were characterised by performance measures with R2 values lying between 0.657 and 0.979. A different character of change in surface roughness was found for sheets covered with and not covered with a soft layer of technically pure aluminium. In the case of Alclad sheets, increasing the value of the incremental vertical step size increases the value of the surface roughness parameters Sa and Sz. In the case of the sheets not covered by Alclad, reduction of the tool rotational speed increases the Sz parameter and decreases the Sa parameter. An obvious increase in the Sz parameter was observed with an increase in the incremental vertical step size.

Study on the incremental sheet forming of CFRP sheet

Abstract: Due to the increasing demand, carbon fiber reinforced plastics (CFRP) have become more and more important in many fields. In this study, a hybrid incremental sheet-forming technique for carbon fiber reinforced thermosets (CFRTS) was developed and applied. In this technique, a layer of CFRP sheet was placed under another layer of mild steel sheet called the dummy sheet. Various experiments were conducted, and the results show that this forming strategy can be applied to CFRP sheets having single-or multi-layer prepregs. In addition, the mesoscale model simulation using ABAQUS/Explicit was performed for the incremental sheet forming (ISF) process of the CFRP sheet, and the effect of orientation of fiber on the forming process was discussed. The FE simulation results for the ISF of the CFRP sheet was able to predict the deformation shape and shear angle of the CFRP sheet accurately compared to the experiment.

Investigation of Surface Roughness in Incremental Sheet Forming of Conical Drawpieces from Pure Titanium Sheets

Abstract: The article presents the results of the analysis of the influence of incremental sheet forming process parameters on surface roughness measured on both sides of conical drawpieces made from pure titanium Grade 2 sheets. The experimental plan was created on the basis of a central composite design. The study assumed the variability of feed rate, spindle speed, and incremental step size in the following range: 500–2000 mm/min, 0–600 rpm, and 0.1–0.5 mm, respectively. Two strategies differing in the direction of the tool rotation in relation to the feed direction were also analysed. Analysis of variance is performed to understand the adequacy of the proposed model and the influence of the input parameters on the specific roughness parameter. The sensitivity of the process parameter on the selected surface roughness parameters was assessed using artificial neural networks. It was found that the change in the surface roughness of the inner surface of the drawpiece is not related to the change of surface roughness of the outer side. The morphology of the outer surface of the draw pieces was uniform with a much greater profile height than the inner surface that had interacted with the tool. Taking into account the outer surface of the drawpiece, the direction of tool rotation is also most closely correlated with the parameters Sa, Sz, and Sku. Step size and feed rate provide the highest information capacity in relation to skewness and kurtosis of the inner surface of the drawpiece.

Surface quality analysis of AZ31B Mg alloy sheet in ultrasonic-assisted warm single-point incremental forming

Abstract: With a view to improving the surface quality of the magnesium (Mg) alloy at a warm temperature, the ultrasonic-assisted warm single-point incremental forming (SPIF) is proposed. The surface quality of the Mg alloy during the warm SPIF is primarily affected by two parts: the orange peel patterns of the non-contact surface and the scratches and adhesive wear of the contact surface. In this work, the surface quality of the AZ31B Mg alloy sheet parts at different forming temperatures and ultrasonic amplitudes is evaluated by examining the surface roughness and topography. The results show that the generation of orange peel patterns is significantly affected by temperature. In addition, scratches and adhesive wear of the contact surface increase with the rising temperature. After applying the ultrasonic vibration (UV), the quality of both the non-contact and the contact surfaces of the parts is significantly improved, but too large ultrasonic amplitude slightly reduces the surface quality. Moreover, the microstructural examination results show that UV has a great effect on dynamic recrystallization and grain refinement, which positively affects surface quality improvement.

Sustainability assessment of incremental sheet forming: a review

Abstract: 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.