Single Point Incremental Forming Technology Research Articles

A Combined simulation and experimental investigation on tool radius influence on enhancing the formability SPIF process for Al1050 sheet material

This research presents a comprehensive investigation into the pioneering domain of single point incremental forming (SPIF), focusing on elucidating the nuanced interplay between tool radius and formability. By employing a combination of rigorous simulation and experimental methodologies, the study sheds light on the pivotal influence of tool radius on forming performance. Various tool radius values spanning from 2 to 7 are systematically tested in conjunction with corresponding forming angles, revealing crucial insights into their synergistic effects. A critical threshold radius (Rt) is discerned, representing the point at which optimal formability is attained. Below this threshold, a decline in formability is observed, attributed to excessive surface cutting and metal pressing phenomena evident in tests utilizing pointed tools. Finite element (FE) analysis corroborates these findings, demonstrating that compression beneath the tool center induces unstable strain, consequently diminishing forming height as tool radius decreases. Conversely, beyond the Rt, an increase in tearing is noted due to reduced compression. This underscores the delicate balance required in selecting an appropriate tool radius to maximize shaping capacity in SPIF processes. Importantly, the research highlights the significance of achieving high compression capacity alongside an optimal tool radius, emphasizing the intricate yet essential factors influencing SPIF’s formability and shaping capabilities. Furthermore, this study contributes to the advancement of SPIF technology by uncovering novel insights into the dynamic relationship between tool geometry and formability, thereby paving the way for enhanced process optimization and design in various manufacturing applications. This research delves into the innovative realm of SPIF by exploring the intricate relationship between tool radius and formability. Through meticulous simulation and experimentation, the study unveils the pivotal role of tool radius in forming performance. The different values of tool radius, ranging from 2 to 7, are coupled with appropriate forming angles. A critical Rt is identified, where optimal formability is achieved. Conversely, below this threshold, formability declines due to excessive surface cutting and metal pressing, observed in tests employing pointed tools. FE analysis substantiates that compression below the tool center triggers unstable strain, diminishing forming height with decreasing tool radius. Notably, above the Rt, an increase in tearing is observed due to decreased compression. In this context, attaining high compression capacity alongside an appropriate tool radius emerges as the key to maximizing shaping capacity in SPIF.

Determination of the Optimized Parameter of the Processing of SUS 304 Sheet Material to the Formability by SPIF Technology

Single-Point Incremental Forming (SPIF) is a flexible technology that can form a wide range of sheet metal products without the need for using punch and die sets. As a relatively cheap and dieless process, this technology is preferable for small and medium customised production. However, the SPIF technology has drawbacks, such as the geometrical inaccuracy and the thickness uniformity of the shaped part. For the purpose of determining the optimal value for the technological parameters from the experimental results when evaluating the forming ability through the strain angle α during the processing of SUS 304 sheet material by SPIF technology. The article has conducted experiments to collect parameters; and experimental planning to establish a mathematical model, determine the optimal value for the parameters of the machining process such as tool diameter, tool feed and tool running speed.

The Formability of Perforated TA1 Sheet in Single Point Incremental Forming.

In light of the analysis on the single point incremental forming (SPIF) principle of perforated titanium sheet and the corresponding peculiarities during the forming process, it is found that the wall angle constitutes the pivotal parameter influencing the SPIF quality of the perforated titanium sheet, and this is also the key evaluation index to test the application of SPIF technology on a complex surface. This method for integrating the experiment and the finite element modelling was utilized in this paper to study the wall angle range and fracture mechanism of Grade 1 commercially-pure α titanium (TA1) perforated plate, plus the effect of different wall angles on the quality of perforated titanium sheet components. The forming limiting angle, fracture, and deformation mechanism of the perforated TA1 sheet in the incremental forming were obtained. In accordance with the results, the forming limit is related to the forming wall angle. When the limiting angle of the perforated TA1 sheet in the incremental forming is around 60 degrees, the fracture mode is the ductile fracture. Parts with a changing wall angle have a larger wall angle than parts with a constant angle. The thickness of the perforated plate formed part does not fully satisfy the sine law, and the thickness of the thinnest point of the perforated titanium mesh with different wall angles is lower than that predicted by the sine law; therefore, the actual forming limit angle of the perforated titanium sheet should be less than that predicted by a theoretical calculation. With the increase in the forming wall angle, the effective strain, the thinning rate, and the forming force of the perforated TA1 titanium sheet all increase, while the geometric error decreases. When the wall angle of the perforated TA1 titanium sheet is 45 degrees, the parts with a uniform thickness distribution and good geometric accuracy can be obtained.

Multistage Tool Path Optimisation of Single-Point Incremental Forming Process.

Single-point incremental forming (SPIF) is a flexible technology that can form a wide range of sheet metal products without the need for using punch and die sets. As a relatively cheap and die-less process, this technology is preferable for small and medium customised production. However, the SPIF technology has drawbacks, such as the geometrical inaccuracy and the thickness uniformity of the shaped part. This research aims to optimise the formed part geometric accuracy and reduce the processing time of a two-stage forming strategy of SPIF. Finite element analysis (FEA) was initially used and validated using experimental literature data. Furthermore, the design of experiments (DoE) statistical approach was used to optimise the proposed two-stage SPIF technique. The mass scaling technique was applied during the finite element analysis to minimise the computational time. The results showed that the step size during forming stage two significantly affected the geometrical accuracy of the part, whereas the forming depth during stage one was insignificant to the part quality. It was also revealed that the geometrical improvement had taken place along the base and the wall regions. However, the areas near the clamp system showed minor improvements. The optimised two-stage strategy successfully decreased both the geometrical inaccuracy and processing time. After optimisation, the average values of the geometrical deviation and forming time were reduced by 25% and 55.56%, respectively.

Characterisation of geometrical and physical properties of a stainless steel denture framework manufactured by single-point incremental forming

In recent years, numerous scientific and technological innovations have been introduced in the fields of medicine and dentistry. The application of computer-based engineering techniques has enabled significant improvement in the design and performance of biomedical components, including implants and prostheses. Innovative and flexible manufacturing methods, such as single point incremental forming (SPIF), allow the cost-effective production of these “custom-made” components. The SPIF technology has been employed to manufacture a metal denture base plate (framework) of a complete maxillary (upper) denture to replace a traditional prosthodontic procedure based on a lost-wax technique, which is time-consuming and requires much manual work. Stainless steel sheet of quality X6Cr17 and thickness of 0.5 mm was adopted due to its biocompatibility, good mechanical properties, and reasonable price. The SPIF process was completely designed in a digital environment with a focus on achieving high quality and accuracy of the part followed by experimental verification. For validation, the formed part was compared in terms of the geometry and mechanical strength with the reference one fabricated using the lost-wax technique. The results obtained confirmed the high dimensional accuracy and good strength of the SPIF-made part. The experimental investigations also included analysis of sheet thinning, surface roughness, and microstructure.

A Research of Optimization of the Forming Parameters to the Minimum Radial Dimension Error when Forming Sheet by HOTSPIF Technology

Single Point Incremental Forming (SPIF) technology has become popular and familiar for forming sheet, especially in single, small and prototype batch production in many fields such as medicine, aviation, automobile... However, sheet materials with high hardness and durability are difficult to deform and shape because of their high properties. In that case, if we determine a set of logical suitable technological parameters such as temperature T (°C), speed of forming Vxy (mm/min), vertical tool feed z (mm) and tool diameter D (mm) for single point incremental forming at high temperature (Hot SPIF) technology we will get high precision dimension product. The paper presents a study to optimize the main technological parameters when processing non-alloy Titanium sheet materials by HOT SPIF technology to get the smallest error in the radial direction of the product.

A Research on Optimization of Technological Parameters to the Objective Function of the Deep Dimensions when Forming Sheet Material by HOTSpif

Single Point Incremental Forming (SPIF) technology has become popular and familiar in sheet materials forming, especially in single manufacturing, prototype manufacturing and in the medical field.... However, sheet materials with high hardness and durability are difficult to deform and shape because of their high properties. In that case, when we determine the main logical technological parameters such as forming temperature T (°C), speed of forming Vxy tool (mm/min), depth tool feeding z (mm) and tool diameter D (mm) tool, it is possible to apply HOT SPIF technology at high temperature to form these materials. The paper presents a study of optimization the main technology parameters when processing non-alloy Titanium sheet materials with HOT SPIF technology to get the smallest depth dimension error ΔH.

Analytical Computing Stresses and Strains in Single Point Incremental Forming

Nowadays, Single Point Incremental Forming (SPIF) has become popular for metal sheet forming technology in industry in many advanced countries. In the recent decade, many relative studies have concentrated on this new technology of forming sheet by Finite Element Method (FEM) as well as by empirical way. There were very rare studies by pure analytical computing and P.A.F. Martins et al. under a title “Theory of single point incremental forming” performed almost all these researches were based on the analytical framework of SPIF in 2008. After careful studying on this research, we found out its light illogical result: the stresses inside of a random point in the workpiece sheet are constant and not related to the coordinate of the formed point of the sheet. Therefore, it cannot explain the mechanism of rupture and tear of the sheet that is really a serious restriction of the SPIF technology nowadays. This paper dedicates to suggest a new version of pure analytical computing the normal stresses at a random formed point in the sheet that could explain the tear mechanism and a FEM simulation was also carried out also to prove the conviction of the recommended formula.

Characterisation of Polyamide (PA)12 Nanocomposites with Montmorillonite (MMT) Filler Clay Used for the Incremental Forming of Sheets

In this paper, the preparation and characterisation of polymer materials suitable for single point incremental forming (SPIF) technology were performed. Three different kinds of mixtures were selected: a mixture of neat polyamide 12 (PA12), a nanocomposite with PA12 matrix and 1% clay (Cloisite 93A), and a nanocomposite with PA12 matrix and 3% clay (Cloisite 93A). Materials were produced using a melt intercalation method followed by compression moulding. According to the needs of SPIF technology, morphological and mechanical properties were investigated in the obtained mixtures. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) were used to characterize morphological properties. It was determined that the most desired obtained exfoliated structure of clay in the polymer matrix was achieved. Static tensile testing and dynamic mechanical analysis as well as the determination of glass transition temperature and crystallinity of all analysed materials were used to obtain mechanical and thermal properties of the mixtures. The results obtained for each mixture were compared with respect to the content of clay. The content of clay (Cloisite 93A) showed a strong influence on the properties of the obtained materials. The presence of clay (Cloisite 93A) affected the increase of tensile strength and Young’s modulus, while its influence on the attained elongation was not unique.

A Research of the Precision of Titanium Sheet Formed by Hot Incremental Sheet Forming Method

Single Point Incremental Forming (SPIF) is a recent technology of forming sheet in several decades. Nowadays, SPIF technology is still continued to be studied, applied and ameliorated in sheet manufacturing in industry. However one of the difficulties of the technology is the forming angle is still small (smaller than 800 according the properties of metal sheets). This paper recommends a measure of increasing the plasticity of the sheet by heating in time of forming by SPIF technology. Naturally, the plasticity of metal sheet increases by the temperature of the material in forming process with its limitation and constraint. The paper represents the effect of heating metal sheet through the empirical process of SPIF technology directed by the design of experiment (DOE). The analyses of the results of experimental process is applied to show the effect of heating to the precision of Titanium sheet. Finally, some private opinions about the heating in SPIF are also mentioned as a very tiny contribution of the research for the new technology.

A functional methodology on the manufacturing of customized polymeric cranial prostheses from CAT using SPIF

PurposeThis paper aims to propose a functional methodology to produce cranial prostheses in polymeric sheet. Within the scope of rapid prototyping technologies, the single-point incremental forming (SPIF) process is used to demonstrate its capabilities to perform customized medical parts.Design/methodology/approachThe methodology starts processing a patient’s computerized axial tomography (CAT) and follows with a computer-aided design and manufacture (CAD/CAM) procedure, which finally permits the successful manufacturing of a customized prosthesis for a specific cranial area.FindingsThe formability of a series of polymeric sheets is determined and the most restrictive material among them is selected for the fabrication of a specific partial cranial prosthesis following the required geometry. The final strain state at the outer surface of the prosthesis is analysed, showing the high potential of SPIF in manufacturing individualized cranial prostheses from polymeric sheet.Originality/valueThis paper proposes a complete methodology to design and manufacture polymer customized cranial prostheses from patients’ CATs using the novel SPIF technology. This is an application of a new class of materials to the manufacturing of medical prostheses by SPIF, which to this purpose has been mainly making use of metallic materials so far. Despite the use of polymers to this application is still to be validated from a medical point of view, transparent prostheses can already be of great interest in medical or engineering schools for teaching and research purposes.

Recommendation of a Measure for Enhancing the Precision of Dimensions of Foil Products in Single Point Incremental Forming Technology

Single Point Incremental Forming (SPIF) has become a popular technology of forming sheet materials in the recent decades. However, the springback phenomenon, an inborn property of almost all elasto-plastic materials, reduces the precision of dimensions of the products by the finished forming session. This paper attempts to find out a measure to minimize this unwanted obstacle by using both empirical and simulating methods in order to define the relations of springback values among the forming parameters such as diameter of the forming tool, its revolution per minute, its velocity and its feed rate. Analyzing these equations to extract the appropriate parameters of forming for enhancing the precision of SPIF products is the final aim of this paper.

Channel Mill’s Top Shell Prototyping with the Single Point Incremental Forming Technology of Sheet Metal

First of all, the theory and application of the Single Point Incremental Forming (SPIF) technology of sheet metal are introduced at the beginning of this paper; second, several traditional forming technologies of channel mill’s top shell are compared; third, The advantages of SPIF Technology of Sheet Metal in channel mill’s top shell prototyping are analyzed; finally, the steps and methods of channel mill’s top shell design and prototyping with SPIF technology are elaborated through a real business case.

The Application of Single Point Incremental Forming Technology of Sheet Metal in Bus Prototyping

First of all, the theory, advantages and application of the Single Point Incremental Forming (SPIF) technology of sheet metal are introduced at the beginning of this paper; second, the traditional forming technologies of bus’s face and back in Chinese bus industry are compared; third, The advantages of the SPIF Technology of Sheet Metal in Bus Prototyping are analyzed; finally, the steps and methods of bus’s face design and prototyping with SPIF technology are elaborated through a real business case.