The paper presents the analysis of different quality criteria of longitudinal seam welds that appear in aluminium profiles during extrusion using porthole dies. The physical background and ...limitations of the most widely used criteria are discussed. A new improved dimensionless welding quality criterion that takes into account the unbalances of metal flow is proposed by the authors. It is based on analysis of simulation results obtained by QForm Extrusion FEM software and experiments. The authors also introduced a comparative classification of longitudinal seam welds based on the practical application of profiles. It allows the user to characterise the quality of a seam weld depending on its specific application and make a decision regarding its suitability for certain technical requirements. The proposed criterion has been approved by industrial experiments for different types of profiles. Particularly its numerical critical value has been found for AA 6082 alloy. The quantitative correspondence between welding types and values of developed criterion is also defined.
Drop stamping of valve-type flange rod forgings is researched using computer simulation in the “QForm” software. The effect of technological parameters on the power parameters, the stress-strain ...state and the nature of the metal flow, the temperature over the forging cross section during stamping is clarified. The optimal dimensions of the initial billet and the geometry of the tool are determined, which provide minimal technological efforts and optimal forming conditions.
The present article is focused on the regression-based generalization of FEM simulation results, derived through the introduction of QForm 2D FEM software to copper workpieces simulated flow through ...2θ angular dies with external R and internal r die radii in channel intersection zone, and the width of the inlet and outlet die channels is a = 35.4 mm. Regression power dependences for ECAE strain, strain unevenness, and workpiece waste fore part area have been derived for the 125 cases of FEM simulations for the angular dies with different values of channel intersection angles 65˚ ≤ 2θ ≤ 135˚, external and internal die dimensionless radii 0.028 ≤ R/a; r/a ≤1.977 and dimensionless workpiece length 5.226 ≤ L/a ≤ 16.836. Good agreement of derived computational results with known published experimental and computational data for strain and strain unevenness has been found. The derived results of regression analyses provide improvement in the understanding of the influence of generalized ECAE die geometry and workpiece length on copper workpiece pressure working conditions.
—A technological process of hot die forging of a crosspiece has been developed using QForm computer simulation. The influence of the technological parameters on the force parameters and the filling ...of the die cavity is investigated. The state of stress and the temperature fields in a forging, the optimum shape and sizes of the initial workpiece ensuring the minimum technological forces, forging passes, the optimum conditions for filling the die cavity, and forging cooling conditions are determined. The optimum forging scheme has been determined.
The parameters of hot die forging of piercing mill mandrels are determined by computer modeling in the QForm software suite. New process steps are suggested. The influence of process variables on the ...force parameters of the process is analyzed as well as the stress-and-strain state and temperature fields of the forging and tool by steps. A design of punch tools is suggested.
A technological process for hot stamping of two-layer mandrels of a piercing mill has been developed. Technological process scheme is offered. By computer simulation in the QForm program, the ...influence of technological parameters on process force parameters, the stress-strain state and temperature forging fields, and the tool was studied by transitions. Die tooling design is proposed.
Preform design is a key step in the development of hot forging processes. Optimal preform shape must ensure complete die fill with minimal flash and reduced forming load while avoiding flow defects ...like laps. Despite numerous works in this field, preform design is still often based on the trial-and-error method. There is an approach to preform design based on equipotential or isothermal surfaces obtained from a Laplace equation in the domain between two shapes representing the workpiece and the final forging. This method has not been widely applied to practical implementation. It requires proper, but not obvious, selection of the most suitable equipotential surface to be converted to a CAD model to create a preform shape and then creating a die block design based on this shape to perform further optimisation of the technological process by means of simulation. This routine requires several geometrical transformations between simulation and design programs that can be difficult to accomplish using general-purpose CAD programs. In the presented work the authors have integrated QForm metal forming simulation software with a specially developed variant of а CAD system to automate the data transition from finding of the isothermal surfaces used as prototypes of the preform shape with subsequent die blocks creation and further verification of the technology by simulation. The method is illustrated by industrial cases.
Titanium alloys are widely used in the aerospace industry as a structural material. Since this application is critical, the titanium alloys must have high mechanical properties both at room and at ...elevated temperatures. The thermomechanical processing of titanium alloys during forging determines the microstructure of the manufactured parts to a large extend. The final mechanical properties are attained by the subsequent heat treatment. Hardening heat treatment, such as solid solution treatment and aging, improves both the strength and ductility of the material. Simulation of metal forming processes with the evolution of the microstructure and prediction of the final mechanical properties are extremely important and allow to effectively develop a technological process for the production of high-quality parts. The most widely used titanium alloy is Ti-6Al-4V, which combines high mechanical properties and satisfactory processability and can be used at temperatures up to 350 °C. In this work samples of Ti-6Al-4V alloy having a lamellar structure with different morphology and a duplex structure with different globular alpha-phase fractions and average grain sizes have been studied. The mechanical properties at the room temperature were determined using compression tests. These experimental data were used to develop a model that allows for predicting the mechanical properties of Ti-6Al-4V alloy forgings after the final heat treatment. The model has been tested by forging a turbine blade using the QForm software.
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