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Incremental sheet forming (ISF) is a relatively new flexible forming process. ISF has excellent adaptability to conventional milling machines and requires minimum use of complex tooling, dies and forming press, which makes the process cost-effective and easy to automate for various applications. In the past two decades, extensive research on ISF has resulted in significant advances being made in fundamental understanding and development of new processing and tooling solutions. However, ISF has yet to be fully implemented to mainstream high-value manufacturing industries due to a number of technical challenges, all of which are directly related to ISF process parameters. This paper aims to provide a detailed review of the current state-of-the-art of ISF processes in terms of its technological capabilities and specific limitations with discussions on the ISF process parameters and their effects on ISF processes. Particular attention is given to the ISF process parameters on the formability, deformation and failure mechanics, springback and accuracy and surface roughness. This leads to a number of recommendations that are considered essential for future research effort.

Now-a-days, the application of hard tuning with CBN tool has been massively increased because the hard turning is a good alternative to grinding process. However, there are some issues that need to be addressed related to the CBN grades and their particular applications in the area of hard turning process. This experimental study investigated the effects of three different grades of CBN insert on the cutting forces and surface roughness. The process of hard turning was made using the AISI H13 die tool steel at containing different hardness (45 HRC, 50 HRC and 55 HRC) levels. The work material were selected on the basis of its application in the die making industries in a range of hardness of 45–55 HRC. Optimization by the central composite design approach has been used for design and analysis. The present study reported that the cutting forces and surface roughness are influenced by the alloying elements and percentage of CBN in the cutting tool material. The work material hardness, feed rate and cutting speed are found to be statistically significant on the responses. Furthermore, a comparative performance between the three different grades of CBN inserts has been shown on the cutting forces and surface roughness at different workpiece hardness. To obtain the optimum parameters from multiple responses, desirability approach has been used. The novelty/robustness of the present study is represented by its great contribution to solve practical industrial application when is developed a new process using different CBN grades for hard turning and die makers of workpiece having the hardness between 45 and 55 HRC.

The H13 hot-work tool steel is renowned for its exceptional toughness, hardenability, thermal strength, and hardness, as well as its outstanding resistance to thermal fatigue and wear, which makes it a preferred choice for hot extrusion dies. This study employed a comprehensive process control methodology, including high-temperature homogenization, precision forging, high-temperature normalization, and isothermal spheroidizing annealing, to optimize the microstructure of H13 tool steel and improve mold quality. The results indicated that the macrostructure of the treated H13 steel was dense and uniform, with no observable segregation defects or impurities. The macrostructure exhibited a general porosity rating of 0.5, with both central porosity and ingot segregation also rated at 0.5. The steel matrix was characterized by a uniform spheroidized structure, with an improvement in the spheroidization grade to AS3. Additionally, segregation phenomena were significantly mitigated, leading to a more homogeneous distribution of internal elements. Post-treatment, the average impact energy of the H13 die steel ranged from 271 to 316 J, thereby satisfying the impact energy requirements established by the North American Die Casting Association for high-quality steel. The optimization of processing techniques resulted in a remarkable enhancement of the microstructure of H13 die steel, thereby significantly improving its mechanical properties.

This paper provides a review of the methods developed over the years for reducing working forces for the precision metal forming processes. Precision forging normally involves completely, or near completely closed cavity dies with no or minimal draft, making features on the extremities difficult to fill and requiring high loads. Means to minimise load, in order to enhance tool life, or reduce press capacity are crucial to the success of precision forging processes. The main concentration of this study is on design features which can be incorporated in tooling and/or workpiece in order to assist in minimisation of forging load while achieving complete die filling. The load reduction methods are presented using examples mainly of precision gear forging, which is representative of the precision forging of other axisymmetric components with complex peripheral shape. The methods reviewed are divided into the categories of (i) billet design, (ii) tool design and (iii) process design. Their effects on forging load reduction for precision forging, along with the authors’ opinions as to the benefits, drawbacks and applicability of each, are presented.

More than 700,000 people die by suicide each year, and many more engage in suicide attempts and experience a mental disorder. Suicides particularly affect the working age population. It is the fourth leading cause for death in young people aged 15-29; more than half of global suicides (58%) in 2019 occurred before the age of 50 years. This topic is gaining attention in workplace settings throughout the world. The World Health Organization estimated that in a company of 1,000 employees, 200-300 workers will suffer from a serious mental health problem in any given year, one worker will die by suicide every ten years, and for every employee who dies by suicide, another 10-20 will make a suicide attempt. Recent epidemiological research indicates an increasing trend in workplace related suicides. Here, Greiner and Arensman examine whether work can contribute to people taking their own lives.

Massively carbon-supersaturated (MCSed) tool steel dies were developed to make galling-free forging products from titanium bar feedstocks in dry conditions without lubricating oils. Two types of tool steel dies were used, SKD11 and ACD56, following the Japanese Industrial Standard (JIS). The plasma-immersion carburizing process was employed to induce massive carbon supersaturation in two kinds of tool steel dies at 673 K for 14.4 ks. A pure titanium bar was upset in a single stroke up to the reduction of thickness of 70% using the MCSed SKD11 die. Very few bulging displacements of the upset bar proved that μ = 0.05 on the contact surface of the MCSed SKD11 die to pure titanium work. Two continuous forging experiments were performed to demonstrate that an in situ lubrication mechanism played a role to prevent the contact surface from galling to titanium works in both laboratory- and industry-scaled forging processes. After precise microstructure analyses of the contact surface, the free-carbon film formed in situ acted as a lubricating tribofilm to reduce friction and adhesive wear in continuous forging processes. The MCSed ACD56 dies were also used to describe the galling-free forging behavior of manufacturing eyeglass frames and to evaluate the surface quality of the finished temples. The applied load was reduced by 30% when using the MCSed ACD56 dies. The average surface roughness of the forged product was also greatly reduced, from 4.12 μm to 0.99 μm, together with a reduction in roughness deviations. High qualification of forged products was preserved together with die life prolongation even in dry manufacturing conditions of the titanium and titanium alloys.

Dies are widely used in various manufacturing processes and are considered one of the important aspects of manufacturing industries. DC53 die steel is a recently developed and improved die steel which has good material characteristics as compared with D2 die steel and is replacing D2 die steel due to its improved material characteristics. The wire electric discharge machining is widely used for its machining, because conventional machining is not suitable for its machining. The demand for shorter lead time with improved quality and precision has made die making a challenging task for die makers, and this becomes more challenging with new die steel such as DC53 die steel. For this reason, the Taguchi method is employed and the effect of various factors of high-speed wire electric discharge machining (HS-WEDM) on the machining characteristics such as material removal rate (MRR), kerf width, and surface roughness (SR) of DC53 die steel is investigated. The factors such as pulse on time (Pon), current intensity (C), pulse off time (Poff), and wire speed (WS) are selected. Taguchi L27 orthogonal array is selected for experimenting. Analysis of variance (ANOVA) is used to find the significant factor on each machining characteristic, while analysis of means (ANOM) of signal to noise (S/N) ratio is used to find the optimal value of factors for improving each machining characteristic. It is concluded that current intensity is most significant on MRR and SR, while pulse on time is most significant on kerf width. The optimal value of factors identified for achieving maximum material removal rate is 3-μs Pon, 5-μs Poff, 3-A C, and 11-m/s WS, while for achieving low surface roughness, optimal value of factors are 4-μs Pon, 9-μs Poff, 2-A C, and 9-m/s WS. Moreover, for achieving small kerf width, the factors should be set at the optimal value of 4-μs Pon, 9-μs Poff, 1-A C, and 7-m/s WS.

The inhomogeneity present in the deformation and microstructure during the open die forging of large size ingot significantly influences the mechanical properties of the final part. This study aims to develop a microstructure-based finite element (FE) model and investigate the influence of deformation path on microstructure evolution during the upsetting process of large size ingot of a high strength steel. The difference in deformation path is achieved by modification in anvil shape such as flat, v shape, convex, and concave die. To achieve this goal, hot compression tests were carried out using the Gleeble 3800 thermomechanical simulator. Utilizing the acquired and corrected flow stress data, a material model and a microstructure model were established, and both formulated models were then integrated into the Forge NxT 3.2 finite element simulation software through the inclusion of a dedicated user subroutine. The predictions from the FE analysis were validated with experimental results on standard size hot compression specimens, which allowed for the accurate prediction of the dynamic recrystallized average grain size at the end of hot deformation. Afterwards, the validated FE model was scaled up to simulate the industrial upsetting process, making it possible to investigate the effect of deformation path on inhomogeneity of strain and microstructure evolution at the end of upsetting process for large sized forged ingots. An evaluative analysis of four die geometries, aimed at identifying the optimal die shape for minimizing inhomogeneity in strain and grain size across a large size forged ingot, was conducted. It was found that the convex die provokes the lowest deformation, while the concave die induces the highest deformation values at the center of the ingot. Utilizing the coefficient of variation as an indicator of heterogeneity, it was determined that the v-die and concave die resulted in a more consistent grain size distribution compared to the flat and convex dies.

Currently, the field of microgear manufacturing faces various processing challenges, particularly in terms of size reduction; these challenges increase the complexity and costs of manufacturing. In this study, a technique for microgear manufacturing is aimed at reducing subsequent processing steps and enhancing material utilization. This technique involves the use of trough dies with extrusion-cutting processing, which enables workpieces to undergo forming in a negative clearance state, thus reducing subsequent processing time for micro products. We conducted finite element simulations using microgear dies, measuring stress, velocity, and flow during the forming process of four types of dies-flat, internal-trough, external-trough, and double-trough dies. The results indicated that the buffering effect of the troughs reduced the rate of increase in the material’s internal stress. In the cavity, the material experiences a significant increase in hydrostatic pressure, leading to the formation of a “hydrostatic pressure wall”. This pressure barrier imposes substantial constraints on the flow of the material during dynamic processes, making it difficult for the material to move into the remaining areas. This effectively enhances the blockage of material flow, demonstrating the critical role of hydrostatic pressure in controlling material distribution and movement. In addition, combining the characteristics of both into a double-trough die enhances the overall stability of forming velocity, reduces forming load and energy consumption, and maximizes material utilization. Results further revealed that microgears manufactured using double-trough dies exhibited defect-free surfaces, with a dimensional error of less than 5 μm and tolerances ranging from IT5 to IT6. Overall, this study offers new insights into the traditional field of microgear manufacturing, highlighting potential solutions for the challenges encountered in current microstamping processes.

Growing technological innovation has led to faster, easier, and more efficient methods of getting things done. Owing to increasing requests for parts and the need to enhance 3D printing of sand cores and moulds and their conventional counterparts, Artificial intelligence (AI) and Smart systems are expected to address the existing challenges in using these techniques. Conventional metal-casting techniques often necessitate the application of tools in the design of patterns, cores, dies and moulds. Also, specialised skills are needed for pattern-making in wood, plastic or other materials. Metallurgical models dealing with shrinkage rates, machining, draft allowances and solidification in diverse metals, are essential considerations in pattern designing. Furthermore, the possibility of using 3D sand core and mould printing in high-tech applications necessitates minimal error or error-free production of parts. Therefore, this review explores how AI and Smart systems could be introduced into conventional and 3D printing to make the techniques suitable for high-tech applications, such as in the biomedical, aerospace and automotive industries.