Hydromechanical Deep Drawing Process Research Articles

Experimental Investigations of a Springback in Hydromechanical Deep Drawing of Low Carbon Steel 1008 AISI

Hydro mechanical deep drawing (HMDD) is an emerging technology that reduces the number of sheet-forming stages and increases the production of advanced lightweight materials with intricate shapes. This study aims to verify the springback in HMDD and the effect of holding time and fluid pressure on this phenomenon (springback). The springback was measured using a new method by matching the projector p-300 axes with the cylindrical cup wall. The difference between the wall and the axis represents the springback value. Using a blank of low carbon steel (1008-AISI) with 80 mm of diameter and a thickness of 0.7 mm. The effect of holding time (1, 2, and 3 minutes) and the fluid pressure (0.6, 0.8, and 1 N/mm2) was studied. The used hydraulic oil was (code number 3803). The springback value of a cylindrical cup was calculated using the profile projector P-300. The result showed that the springback phenomenon was presented in the hydromechanical deep-drawing process but at a lower rate than the traditional deep-drawing process. The holding time and fluid pressure significantly affected the springback value. The springback decreased with increasing the fluid pressure and holding time.

Hydro-mechanical deep drawing of conical components: Wrinkling behavior and process enhancement

This study explores the hydro-mechanical deep drawing process of a conical part through finite element simulations using ABAQUS software. The central focus is on investigating the occurrence of wrinkling during the forming process. Given the limitations in generalizing previous studies on wrinkling, there is a critical necessity to comprehensively comprehend and mitigate wrinkling behavior through an investigation into the interplay of various parameters. In response to the recognized challenge of minimizing wrinkles, an experimental setup with a hydro-mechanical deep drawing die was resented, aiming to validate and refine the simulation results. Additionally, a comprehensive study is conducted regarding the effect of fluid pressure, chamber pressure, pre-bulge height, friction coefficients, and sheet thickness on wrinkling behavior. The findings reveal that, at a pre-bulge pressure of 40 bar and a pre-bulge height of 2 mm, the minimum wrinkling height is observed to be merely 0.02 mm — the lowest recorded value. Notably, an increasing drawing ratio demands a 50% higher minimum chamber pressure to prevent wrinkling in the flange. Furthermore, a larger distance between the sheet and the die reduces the safe working range by approximately 57%, impacting the production of a wrinkle-free part. Conversely, elevating the pre-bulge pressure results in a 50% expansion in the safe working area for producing a wrinkle-free part. By explicitly stating the challenge of minimizing wrinkles, this study aims to contribute valuable insights into optimizing the hydro-mechanical deep drawing process for enhanced efficiency and improved product quality.

Optimization of Processing Parameters of Aluminum Alloy Cylindrical Parts Based on Response Surface Method during Hydromechanical Deep Drawing

Aluminum alloy has been proposed as one of the next generation of lightweight body structure materials, which is widely used in the main components of the aerospace field. In order to realize efficient and accurate forming of aluminum alloy cylindrical parts, the response surface method combined with finite element simulation was used to optimize the key processing parameters during the hydromechanical deep drawing process. Three processing parameters of friction coefficient, pressure rate, and fillet radius of the die were selected as the optimization variables, and the maximum thinning rate of cylindrical parts was selected as the optimization evaluation index. The Box–Behnken design was selected to design the experiment scheme. A quadratic response model between the maximum thinning rate and the processing parameters was established by the response surface analysis software Design Expert for experimental design and data analysis. The optimal processing parameter combination was obtained through this model. The results show that the optimal conditions of maximum thinning rate can be met when the pressure rate is 11.6 MPa/s, the friction coefficient is 0.15, and the fillet radius of the die is 8 mm. Finally, the experimental verification was carried out by using the optimized combination of process parameters. It was found that the error between the experimental results and the predicted simulation results was within 5%, and the cylindrical parts which met the quality requirements were finally formed.

New small-scale hydromechanical deep-drawing process using die-integrated active high-pressure generation system

In this study, hydraulic pressure generation and small-scale cylindrical hydromechanical deep-drawing experiments were conducted using a novel die-integrated active high-pressure generation system. The most significant feature is the installation of a hydraulic pressure-generating piston structure inside the die, which enables a high-pressure generation process of 100 MPa or higher inside the die. In addition, by taking advantage of the size effect of a smaller die, a high hydraulic pressure is actively generated using the same equipment as in conventional drawing processes. It was discovered that a piston installed in the die can actively generate a hydraulic pressure of 100 MPa or higher based on the Pascal principle. By downsizing the die, a hydraulic pressure of 100 MPa or higher can be generated using only the power of a small press machine (50 kN). By actively applying high hydraulic pressure counter and radial pressures, small-scale drawability can be significantly improved. Furthermore, the application of the proposed system to single-action presses and progressive dies can enable hydromechanical deep drawing with optimized conditions for each process in a single motion.

Textural and microstructural analyses and ranking of the process parameters in hydro-mechanical deep drawing of AZ31B magnesium sheets

The present research work is a comprehensive study on the hydro-mechanical deep drawing (HMDD) process of AZ31B magnesium alloy at elevated temperatures. Several process parameters including the forming temperature, fluid pressure and initial blank diameter were considered to conduct a full factorial experiment. The changes in the thickness strain and thickness variation of the final product were also chosen as the responses. The outcomes gained from the design of experiment technique demonstrated that the initial blank diameter (with 31.3%), process temperature (with 30.2%) and the fluid pressure (with 18.4%) were respectively the most important factors affecting the quality and homogeneity of the AZ31B drawn cup. Moreover, the appropriate process temperature and fluid pressure for HMDD operation of this alloy were, in turn, 200 °C and 15 MPa. Afterwards, a complete texture analysis was carried out and its relation with the hardness distribution in different regions of the workpiece was examined. In addition, the correlation between the microstructures, obtained from the optical microscopy, scanning electron microscopy and X-ray diffraction, with findings of the hardness tests was studied for the optimally produced cup. Based on the textural inspections, it was found that reduction in the basal texture of the flange area in comparison with the bottom of the product was about 12.5%. Moreover, the maximum increase in the hardness (about 24%) and decrease in the average grain size (about 42%) occurred in the wall area of the final product.

Experimental Investigations of Hydrodynamic Deep Drawing of Galvanized Steel to Form a Hemispherical and Complex Cup

In this work, a blank of galvanized steel blank with 80 mm diameter and 0.7 mm thickness and the hydromechanical deep drawing process to make a hemispherical and complex cup. Hydraulic oil was used to apply different amounts of fluid pressure. The work of this study was done in the following three states: In the first state, the experimental work was done without fluid pressure, so the product has wrinkles. In the second state, flaws like wrinkles were fixed by adding 1N/mm2. At a pressure of 1.7 N/mm2, the third state was done. The results show that a product with a blank holder force (BHF) that is neither too high nor too low may be free of defects. When BHF is low, faults in the cylinder cup look like wrinkles, and when BHF is too high, the cylinder cup breaks. So, the BHF value should change depending on the material, thickness, and nature of the product.

Effects of process variables on the uniformity of Al-St and Al-Mg laminated composite cups produced by hydro-mechanical deep drawing operation

Hydro-mechanical deep drawing (HMDD) process is comparatively a new technique in sheet metal forming. The present study focuses on the use of HMDD for bimetallic components comprising aluminum and steel sheets as well as aluminum and magnesium blanks. Carrying out both experiments and numerical simulations, the effects of process parameters such as drawing depth, the fluid pressure inside the die and the process temperature were profoundly investigated. To study the effect of the process temperature on the quality of the product, the specimens were formed at both the room temperature and 200°C. Considering the maximum thickness strain and thickness variation of the specimens as measures of product quality, various results, including those obtained from the design of experiments (DOE), illustrated significant impacts of all the considered factors on the quality of the final product. The findings also showed that for the bimetallic aluminum/steel specimen, the Al/St layer sequence offered a higher quality compared with the St/Al arrangement under the same process conditions. The amount of thickness strain and thickness variation in the Al/St arrangement, compared with the St/Al sequence, were respectively improved by 27.4% and 12.6%, for the optimal value of the maximum fluid pressure (150 bar). Moreover, the thickness variation of the Al/Mg specimen was smaller than that of Al/St bimetallic cup, regardless of the drawing depth.

Numerical and experimental studies of the formability of the low carbon steel (11008-AISI) by using hydromechanical deep drawing

The hydromechanical deep drawing process (HDD) is one of the low-cost forming processes with a high accuracy of the product dimensions compared to the other forming processes. This work aims to investigate the foamability of the low carbon steel (11008-AISI) by using hydromechanical deep drawing for two sheet thicknesses (0.5 and 0.7) mm numerically using the finite element method and experimentally. The final product of the process was a cylindrical cup of (40) mm outer diameter for both sheets. Different forming pressure values (0, 0.8 and 1.5) N/mm2 ware tested to predict the optimum fluid pressures and blank holder forming, (the optimum fluid pressure is 1.5 N/mm2). It was found that the required fluid pressure is increased with increase of sheet thickness, and also that the required press pressure is increased with the increase of sheet thickness. The numerical simulation was successfully achieved the modeling of hydromechanical low carbon steel deep drawing (11008-AISI) with a maximum deviation (7 percent) of compared to the experimental finding in predicting (thickness distribution and strain distribution). Also, it was found the blank holder force values hance a significant effect in a voiding the wrinkling and to avoid the product rupture.

A novel hydrodynamic deep drawing utilizing a combined floating and static die cavity

A novel method named hydrodynamic deep drawing process utilizing a combined floating and static die cavity (HDDC) was proposed in this research, in order to depress wrinkling during hydrodynamic deep drawing process to form a conical cup with higher height. A special experimental setup of a combined die cavity, which a static chamber inlaid with an inner floating die cavity, was designed to implement the modified hydrodynamic deep drawing experiments. At first, the feasibility of the modified method was evaluated in detail by numerical analyses and experimental tests. Then, the effects of the liquid counter pressure in die cavity on the forming process were also studied. It was found that the proposed method HDDC was feasible and the suppressing wrinkling effect dramatically came into being by using a floating die cavity during the hydrodynamic deep drawing process for conical cups of higher height. The rigid contact between the crater corner of the floating cavity and the blank contributes to the suppressing wrinkle effect during the hydrodynamic deep drawing process utilizing a combined floating and static die cavity. The hydrodynamic deep drawing process of conical cups utilizing a combined die cavity becomes more robust compared with the conventional hydromechanical deep drawing process.

An investigation of the effect of temperature variability of the tools on FEA of the warm hydromechanical deep drawing process

Warm hydromechanical deep drawing process is an innovative manufacturing technology that offers considerable increase in the formability of the materials. However, the weakness of the process lies in its complexity. For a successful process, the optimum temperature distribution of the material must be achieved. In addition, optimum loading profiles (pressure of fluid and force of blank holder) should be applied according to the punch position. These conditions can most easily be determined with the proven finite element analysis (FEA). In this study, the effect of the temperature variability of the tools on the results of the FEA was investigated. Namely, the study aims at investigating whether the temperature variability of the tools needs to be modeled or not in FE analysis. For a simple and fast analysis, it is generally accepted that the tools have a homogeneous temperature distribution and the temperature is constant throughout the process. However, in the experiments in this study, the temperatures of the tools changed considerably. The temperature variability of the tools was first measured in the experiments and then modeled in the FEA. In the analysis performed for the AA 5754 aluminum alloy, the thickness distribution of the deep drawn part was compared with the results of an FEA performed at a constant and same temperature condition. Results in both conditions were very close to each other and indicated that there is no need to obtain and model the temperature distribution or temperature variability of the tools throughout the process. It was possible to perform the FEA with acceptable accuracy by assuming a constant and homogeneous temperature distribution in the tools throughout the process.

An investigation on the effects of the process parameters of hydro-mechanical deep drawing on manufacturing high-quality bimetallic spherical-conical cups

This paper aims to analytically, experimentally, and numerically study the hydro-mechanical deep drawing (HMDD) process of bimetallic specimens. The blank included aluminum and steel sheets used to produce double-layer conical-spherical cups. The punch geometry, maximum fluid pressure, pre-bulge pressure, layer arrangement, and the drawing depth were the process parameters investigated in this article. Two criterions based on the thickness strain and thickness variation were used to assess the effects of these variables on the quality of the final product. The results of the analytical modeling and numerical simulations were verified by comparing with the related experimental data. Different outcomes were in acceptable agreement with each other. Based on the findings obtained, by increasing the fluid pressure up to 15 MPa, the quality of the final product was enhanced. Moreover, by applying the pre-bulge pressure in the HMDD process, the separation between the layers as well as the thickness variation decreased. The highest improvements in the values of the maximum thickness strain and thickness variation in the current investigation were gained to be 57% and 68%, respectively, in comparison with the traditional state of the deep drawing process.

Optimization of the geometrical parameters for elevated temperature hydro-mechanical deep drawing process of 2024 aluminum alloy

This research is concerned with the effects of the geometrical parameters of the die in elevated temperature Hydro-Mechanical Deep Drawing (HMDD) process of 2024 aluminum alloy. A Group Method of Data Handling (GMDH) process was used to train a neural network in order to study the process behavior. Based on the maximum reduction in sheet thickness and the uniformity of the final product, an objective function was constructed. The Bees Algorithm (BA) was used to achieve the optimal values for process variables. To verify the simulation results, they were compared with the experimental findings gained via this research and an appropriate correlation was observed between these results. This comparison showed that, by optimization of the geometrical parameters of the process, the value of the combined objective function was the best one compared with all of the cases tried in the present investigation.

Numerical optimization of warm hydromechanical deep drawing process parameters and its experimental verification

Abstract Warm Hydromechanical Deep Drawing (WHDD) is considered as an effective sheet metal forming process to overcome low formability problems of lightweight materials, such as aluminum and magnesium alloys, at room temperature. WHDD process combines the advantages of Hydromechanical Deep Drawing (HDD) and Warm Deep Drawing (WDD) processes. In this study, interactive and combined effects of Pressure (P) and Blank Holder Force (BHF) variation on the formability of the AA 5754 aluminum alloy sheets in the WHDD process were investigated experimentally and numerically. Different from available studies, the optimal fluid pressure (P) and blank holder force (BHF) profiles, which were determined numerically using adaptive FEA integrated with fuzzy logic control algorithm (aFEA-FLCA), were validated experimentally for the first time in literature. Consequently, limiting drawing ratios (LDR) of AA5754 material were recorded as 2.5, 2.625, and 3.125 for HDD, WDD, and WHDD processes, respectively. Thus, it was demonstrated that the formability of lightweight materials, such as AA5754, could be increased significantly using the WHDD process through the proposed optimization method. This method was also implemented into the WHDD of an industrial part with complex geometry, successfully forming sharp features with minimal thinning at reduced levels of force, pressure, and time. Consequently, it is reasonably to state that the method developed in this study can be adopted for the manufacturing of any other part using the WHDD process.

Process parameters selection in manufacturing of sharp conical parts based on Taguchi design of experiments

Among the sheet metal forming processes, hydrodynamics deep drawing and hydromechanical deep drawing process are two main types of the deep drawing process that can fabricate complicated parts. In the hydroforming process, the blank is formed to the desired shape by applying a considerably high hydraulic pressure. In this article, the selection of the process parameters will be investigated during the manufacturing of a pure copper sharp conical part by finite element analysis and experimental tests. Two finite element models are developed for hydrodynamics deep drawing and hydromechanical deep drawing processes. After verification of the FE model by experimental results, the effect of process parameters includes the applied pressure, friction coefficient, die radius and blank holder force on thinning of the blank are investigated. The thinning ratio of blank is calculated in different zones of the conical part under different working conditions determined according to the Taguchi design of experiment methods. Signal to noise ratio analysis has been carried out and the influence of process parameters on the thinning ratio is determined at different zones of the conical part. The results show that the friction coefficient has an important role in the thinning of the conical nose while at the lateral surface of the cone, the die radius is the most effective parameter on the thinning ratio. The results show that by implementing statistical tools (Taguchi method and signal to noise ratio analysis), it is possible to select the proper process parameters conditions and fabricate defect-free parts. In addition, a non-linear regression equation is developed for prediction of thinning ratio in the hydrodynamics deep drawing and hydromechanical deep drawing processes.

The limit drawing ratio in die angled hydromechanical deep drawing method

In the study, the effect of die angle, die radius, die punch, blank holder force, and chamber pressure parameters on the limit drawing ratio (LDR) in die angled hydromechanical deep drawing process was investigated by using Taguchi experimental design method. The effects of the parameters on the limit drawing ratio were numerically examined and compared experimentally using ANSYS packaged software. Also, the data were statistically analyzed by using the ANOVA analysis of variance in order to determine the effects of the parameters on the limit drawing ratio. The results indicated that the chamber pressure value was lower and the limit drawing ratio was higher than the values reported in the literature.

Comparative study of conventional and hydromechanical deep drawing processes based on finite element analysis

A two-dimensional finite element analysis has been performed to investigate hydromechanical and conventional deep drawing processes. The effects of the fluid structure interaction on the material formability, the strain and the thickness distributions are investigated. Large plastic deformation is observed in the plank at the bottom and the corner of the punch. Plastic deformation distribution results show a difference between the hydromechanical deep drawing process and the conventional deep drawing which is due to the friction effect. This latter represents one of the major features of the hydromechanical deep drawing process. Concerning the formability of the blank, the obtained results show that the hydromechanical deep drawing process gives a better formability than the conventional deep drawing process.

Experimental and numerical study of hydro-mechanical deep drawing of 2024 aluminum alloy sheet at elevated temperatures

In the present study, hydro-mechanical deep drawing (HDD) of 2024 aluminum alloy sheet was investigated using the experimental tests and numerical simulations. The experimental tests were done at elevated temperature by considering four heating elements in the fluid chamber of HDD die which provided four temperatures of 25 °C (room temperature), 60 °C, 100 °C, and 140 °C for the HDD process. The effect of fluid chamber pressure was studied on the formability of AA 2024 by considering four pressures of 6, 10, 14 and 18 bar. The numerical simulations of the ABAQUS/Explicit and the Gurson-Tvergaard Needleman (GTN) damage model was used for fracture prediction of AA2024 in the HDD at room temperature. The anti-inference method and numerical simulation of the uniaxial tensile test of AA2024 sheet was used for identification of the GTN parameters. The experimental and numerical results indicated that the formability and forming height of AA2024 increased in the HDD by increasing of the pressure and temperature of the fluid chamber.

การทดสอบหาสมบัติทางกลของเหล็กกล้าคาร์บอนต่ำด้วยการทดสอบแบบเป่าโป่งด้วยน้ำเพื่อนำไปใช้กับการจำลองของกระบวนการลากขึ้นรูปโลหะแผ่นด้วยน้ำ

การทดสอบหาสมบัติทางกลของเหล็กกล้าคาร์บอนต่ำด้วยการทดสอบแบบเป่าโป่งด้วยน้ำเพื่อนำไปใช้กับการจำลองของกระบวนการลากขึ้นรูปโลหะแผ่นด้วยน้ำ

Theoretical, numerical and experimental investigation of hydro-mechanical deep drawing of steel/polymer/steel sandwich sheets

Fabricating flat sandwich sheets into components with a required shape and dimensions is a challenging job in the metal forming field. In this article, hydro-mechanical deep drawing was used for sandwich sheet forming. The aim of the work is to achieve higher drawing ratio of these sheets. Theoretical, numerical and experimental analysis of the hydro-mechanical deep drawing of sandwich sheets was carried out. Separated layers theory method is used for theoretical analysis of the process. Then, the numerical simulation of the process was developed by finite element method. The effect of core layer thickness on the forming force of the sandwich sheet and effective parameters of the process such as strain and forming force was investigated. Experimental works were conducted on the steel/polymer/steel sandwich sheets by a hydro-mechanical deep drawing die. A good agreement was observed between theoretical, numerical and experimental results. The safe zone of fluid pressure for achieving a part without rupture was obtained. It was shown that the limit drawing ratio is increased by increasing the pressure but after a particular point, the limit drawing ratio is decreased by increasing the chamber pressure. It was also observed that maximum drawing ratio for achieving a part without rupture in the hydro-mechanical deep drawing process is higher than conventional deep drawing process.

An Investigation on the Effects of Optimum Forming Parameters in Hydromechanical Deep Drawing Process Using the Genetic Algorithm

The present research work is concerned with the effects of optimum process variables in elevated temperature hydro-mechanical deep drawing of 5052 aluminum alloy. Punch-workpiece and die-workpiece friction coefficients together with the initial gap between the blank holder and matrix were considered as the process variables which, in optimization terminology, are called design parameters. Since both the maximum reduction in sheet thickness and the final product uniformity (thickness variation) are important in the hydro-mechanical deep drawing, they are selected as the objective functions for optimization. After conducting 27 finite-element simulations of the operation and validation of the numerical results, a neural network was trained and combined with the genetic algorithm to obtain the optimum design parameters. The outcomes of this investigation have shown that these optimized process variables simultaneously resulted in the best values for both the objective functions, in comparison with all the conducted finite-element analyses.