Numerical simulation to optimize the mold structure and forming parameters for a large AZ80 magnesium alloy support beam and experimental formation of the support beam using a 40MN numerically ...controlled hydraulic press were carried out. The research results showed that use of a semi-closed mold resulted in full and even deformation of the stair-like support beam forging. Also, the forging could be filled in one step with simple cuboid-shaped billets, thus greatly shortening the forging process. The technique of isothermal forging with a multi-stage-change speed used an ultra-low speed of 0.005mm/s during the final forming process. The resulting billet was fully softened, which greatly reduced the forming load to less than 40MN. Die forgings of the large magnesium alloy support beam were thus produced through isothermal forging with a semi-closed die and multi-stage-change speed. Fine and evenly distributed grains were observed for the formed forgings. The longitudinal and transverse tensile strengths of the main strength-bearing part (bottom) were 394MPa and 398MPa, respectively; their percentage elongations were 9.6% and 9.8%, respectively. In addition, the forgings were processed into parts and passed a trial loading test before being successfully used in helicopters.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Flashless forging is classified as a precise metal forming technology. The main advantages of this technology are the reduction of the flash allowance and the shortening of the manufacturing time by ...eliminating the flash trimming operation. The article presents the process of one-step forging of a stepped shaft made of aluminum with the use of split dies. The process was carried out in cold and hot metal-forming conditions. The forging process was analyzed numerically using the Simufact Forming 15.0 software. The geometrical parameters of the obtained product were analyzed, and the distribution of effective strain, temperature, and the standardized cracking criterion was determined. The process force parameters were also determined. Numerical tests were verified in real conditions with the use of a specially designed device for forging in vertical split dies. Comparison of hot and cold forging in vertical split dies is presented. The comparative analysis results have demonstrated that the hot forging process has more advantages than the cold forging process. The hot forging process ensures higher accuracy of forged parts.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The study deals with the energy-saving process of hot open die elongation forging of heavy steel forgings on an 80 MN industrial hydraulic forging press. Three innovative energy-saving power supply ...solutions useful for industrial hydraulic forging presses were analyzsed. The energy-saving power supply of hydraulic forging presses consists in reducing electricity consumption by the electric motor driving the pumps, reducing the noise emitted by pumps and reducing leaks in hydraulic piston cylinders. The predicted forging force as a function of heavy steel forging heights for various deformation temperatures and strain rates was determined. A simulation model of the 80 MN hydraulic forging press is presented, which is useful for determining the time-varying parameters during the forging process. An energy-saving control for the hydraulic forging press based on the forging process parameters’ prediction has been developed. Real-time model predictive control (MPC) was developed based on multiple inputs multiple outputs (MIMO), and global predictive control (GPC). The GPC has been implemented in the control system of an 80 MN industrial hydraulic forging press. The main advantage of this control system is the repeatability of the forging process and minimization of the size deviation of heavy large steel forgings
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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.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
In this study, different thermomechanical treatment (TMT) routes, combining hot, warm and cold rotary forging with post-deformation annealing at different temperatures, were applied to Ti-18Zr-14Nb ...shape memory alloy to study the influence of these TMTs on the phase composition, structure, texture, mechanical properties, and superelastic behavior of long-length rod stock for fabrication of load-bearing orthopedic implants. The warm and hot forging routes led to the formation of a dynamically recrystallized structure, most likely combined with a dynamically polygonized structure, with an average β-phase grain size of 9 μm (warm forging) and 30 μm (hot forging). After the combination of warm/hot and cold forging with annealing at 525 °С, the alloy exhibited a polygonized β-phase substructure and the best combination of functional properties: low Young’s modulus (37 GPa), large difference between the dislocation and transformation yield stresses (320 GPa), and significant total amount of superelastic and elastic recovery strains (∼4%).
•Ti-18Zr-14Nb alloy was processed by hot, warm and cold rotary forging.•A polygonized β-phase substructure with different initial grain sizes was formed.•A rod sample shows a maximum total recovery strain of ∼5%.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Forging is a primary manufacturing process used in several manufacturing industries. Aircraft and automobile industries are manufacturing products with high‐dimensional accuracy and quality that are ...highly precise or near the required shape. Customers require products that are free of cracks and fulfill their functional requirements. This leads to the advancement of the forging process due to its ability to form complicated and intricate shapes. Herein, a detailed review of the aspects of forging is given in which the optimization of factors like preform design, forging conditions, workpiece dimensions, die design, lubricant properties, and thermal treatment parameters are discussed, enhancing the tool life and forging quality of the product. The selection of die‐forging tool material and methods for enhancing the surface quality of forged products are also reviewed. The article also presents methods for measurement of forging quality, tool life, machine effectiveness, forging image acquisition, and forging parameters, which can significantly reduce the risk of error at every step of the forging process. This review serves as a reference for researchers to increase production rate, enhance the effectiveness of measurement system, and improve the quality of forged products with technological advancement.
A detailed review of the approaches used for improving the surface quality of forgings and methods that can enhance the service life of forging tools is given. These include optimization of forging process parameters, tool design advancement, tool surface treatment, material and lubricant properties, along with measurement techniques for the forging process.
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FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
An advanced process of mandrel forging and necking (MFN) was proposed for a hollow shaft with an inner stepped hole. The conventional mandrel forging process with an equal-diameter mandrel was used ...to form the outer stepped preform, and then the preform was formed into the hollow shaft with an inner stepped hole using the MFN process. A numerical simulation model was established to study the effect of the pressing reduction and the rotation angle on the MFN process. A preforming design method based on the isometric radius difference was given according to the principle of the equal volume, and the parameter relationships between the outer and inner stepped shapes were clarified. The experimental deformation laws of the MFN process were consistent with those obtained by the simulation. The MFN process and its preforming design method provide a new free forging approach for large hollow forgings with inner stepped holes.
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The article discusses the wear of forging tools intended for hot forging processes. It presents the results of an experimental research of a selection of methods to improve the durability of forging ...tools in an industrial die forging process. Improved durability was obtained by the application of thermo-chemical treatment in the form of nitriding and the use of hybrid layers composed of a nitrided layer combined with PVD coatings deposited on the surface. In addition, various nitriding processes were applied and the influence of the phase structure of the nitrided layer was examined. The use of a new coating in this type of application based on non-stoichiometric chromium nitride (CrNx) with the thickness of 12 μm was analyzed. This type of coating was obtained with the use of an innovative technology combining magnetron sputtering and arc evaporation.
The obtained effect of increased durability was verified by means of a comprehensive tool analysis after operational tests, compared with the obtained durability results for the traditionally used tools made of Unimax steel. The research included, among others, determination of the amount of wear by 3D scanning, analysis of the changes in the surface layer of the tools in selected areas using a scanning electron microscope (SEM), observation of the microstructure and measurements of the microhardness. The conducted operational tests and analysis showed that, by means of the proposed methods of increasing durability, the tool life was extended. The best effect was obtained owing to the use of a hybrid layer composed of a nitrided layer (type α) and a coating of 12 μm thickness, because the tools were more resistant to abrasive wear in the analyzed key areas. Studies have confirmed the legitimacy of using hybrid methods combining many techniques simultaneously for increased durability of forging tools.
•Microstructure and properties of hybrid layer have significant influence on the durability of tools in hot forging processes.•STy diversified type of substrate made of nitrided layer can affect the durability of dies covered with PVD coatings.•Hybrid layers consisting of diffusion alpha nitrided layer and CrN coating increased tools' durability by over 80%.•The use of the CrNx coating of non-stoichiometric chromium nitride allows to deposit coatings with a thickness of over 10 μm.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this study, an age-hardenable 2219 Al–Cu alloy was severely deformed by multidirectional forging (MDF) at 360–510°C, followed by solution treatment and T8 aging treatment. The evolution of the ...second-phase Al2Cu particles and the mechanical properties of the T8-aged samples were examined. The results indicated that a higher volume fraction and a more disperse distribution of the fragmented coarse particles were obtained for the sample deformed at low temperatures. The fragmented coarse particles were still difficult to sufficiently dissolve in the Al matrix in the subsequent solution treatment and could act as crack initiation sites, thereby reducing the mechanical properties of the alloy. With increasing the temperature of MDF, the number of coarse particles was gradually decreased, and the particles exhibited a more spheroidized shape after MDF. Correspondingly, more Cu atoms were dissolved in the Al matrix in the subsequent solution treatment, and the uniformity and density of the precipitates after T8 aging were improved. Thus, the mechanical properties of the T8-aged forgings were improved with increasing the temperature of MDF. The optimal mechanical properties were obtained when the deformation temperature was 510°C, with ultimate tensile strength of 431.2MPa, yield strength of 341.3MPa, and elongation of 6.5% at room temperature.
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•Age-hardenable 2219 Al-Cu alloy was processed by MDF at 360–510°C.•Coarse particles were decreased and spheroidized with an increase in MDF temperature.•Coarse particles exhibited a dispersive distribution and elongated shape during MDF at 360°C.•Coarse particles were difficult to sufficiently dissolve during solution treatment.•Optimal mechanical properties were achieved from the forgings MD-Forged at 510°C.
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The article is a review presenting the possibilities of applying modern measuring techniques in the forging industry by using various measuring tools, instruments and machines applied in workshop ...metrology. The work points to different aspects of measuring techniques, emphasizing their importance in the context of safety (achieved forgings – products) and to significant measurement problems due to the extreme conditions in hot forging industrial processes (high cyclic mechanical loads and temperatures). The work also analyses the possibility and validity of applying scanning techniques for the purpose of directly monitoring the quality and changes in geometry of tools in industrial forging processes, without the necessity of dismounting them. In addition, applications of numerical modelling results (FEM) for determining physical quantities that are difficult or impossible to test under industrial conditions (temperature distributions, stresses, deformations, etc.) are presented. The work also presents other options of measuring techniques in the forging industry - including for evaluation of temperature measurements of forging tools, for analysis and improvement of forging tool lifetime, checking the technical condition of forging machines and equipment, as well as for building control and measurement systems with regard to forging forces.
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