Numerical Investigation of Tool Parameters Influence on the Interlock Forming During Flat Clinching Process

Tool parameters play a vital role in the mechanical interlock formation during the flat clinching process, to understand the influence of tool parameters on the interlock formation, the finite element software DEFORM-2D was used to build the numerical model of the flat clinching process, and the numerical model was verified by the experiment. The influences of the punch radius, punch fillet radius, and blank holder radius on the interlock formation of the clinched joint were investigated using the numerical model. Then, the relationship between the punch radius and blank holder radius was studied. The results showed that the interlock gradually increases with the increase of the blank holder radius, after that, the interlock begins to decrease. To maximize the interlock, the punch radius and the blank holder radius should be increased simultaneously. It can be concluded that the blank holder radius and the punch radius should keep in a linear relationship when designing the geometric dimensions of the flat clinch tools, which can promote the application of flat clinching process in car body manufacturing.

Microstructure modeling of a sintered Al–4Si–0.6Mg alloy extruded at semi-solid temperature ranges

The microstructure evolution of sintered and extruded samples of Al–4Si–0.6Mg powder alloys at various semi-solid temperature ranges of 560 °C, 580 °C, and 600 °C, holding times of 600, 1200, and 1800 s, and strain rates of 0.1, 0.2, and 0.3 s−1 was studied. From the stress–strain curves and metallographic studies, Arrhenius grain growth model and Avrami dynamic recrystallization model have been formulated by means of linear regression. Parameters such as peak strain, critical strain, recrystallization fraction, and material constants have been found using the above equations. The experimental and calculated values of various material parameters agree with each other, indicating the accuracy of the developed model. Finite element method-based simulations were performed using DEFORM 2D software, and the average grain size obtained from experiments and simulations was validated by means of average grain size. The relative density of the compacted specimens as well as the extruded specimens was also simulated. The simulation results showed that large grains appeared at high temperatures and at the bottom of the specimen.

Strains under Angular Pressing of a Strip from a Cylindrical Billet

The scheme of non-equal channel angular pressing (non-ECAP) of a magnesium billet has been analyzed. The modeling was performed by DEFORM-2D software. A high level of strain is shown to be achieved during non-ECAP. It leads to more homogenous structure refinement of magnesium and plasticity improvement that could favorably affect the subsequent deformation of a Mg-strip by cold rolling. At non-ECAP-process, the upper part of the strip is noted to be hardened more than the lower one. The lower part is supposed to be formed by extensional strain mainly, meanwhile for the upper one, the prime mechanism is likely to be shear strain. Based on hardness measurement of the samples cut from the obtained Mg-strip, conclusions have been made about the influence of the accumulated strain during non-ECAP on the strength properties of the strip.

Optimization of the Indirect Extrusion Process of Copper-Clad Aluminum Rods by Methods of Statistical Experimental Designs and Numerical Analyses

The success of composite extrusion is influenced by multiple process parameters. In order to investigate the significance of specific parameters during indirect extrusion of copper-clad aluminum (CCA) rods, statistical methods were applied and a central composite experimental design was implemented. The runs of the experimental design were modeled with the finite element method based software DEFORM 2D and evaluated with respect to product quality, described by four response variables. Using variance and regression analyses, as well significant linear and quadratic effects of the five investigated process parameters as interactions between them were identified. Based on a statistical model, an overall optimum setting for the process parameters was predicted utilizing the response surface methodology with a desirability approach. By applying the output of the statistical analysis to an extrusion trial, the extrusion of a high quality CCA rod was achieved. Moreover, the results of the statistical analysis could be verified by comparing predicted and experimentally determined values of the investigated quality characteristics.

Numerical Investigation of a New Production Method for Face Gearings Incorporating Material Predistribution – Pin-to-Gear Method

The research subjects of current investigations at the Institute for Metal Forming Technology (IFU) Stuttgart include the manufacture of face gearings. Usually, gearings are produced by means of a coining process, which causes high process forces that considerably restrict the geometry of the teeth in terms of the height-to-width ratio. In order to avoid these problems, a new forming process has been developed. This technology offers significant advantages, such as the reduction of process forces and the ability to manufacture the required tall and acuminate tooth elements through a cold-forming process. This paper describes the design and functionality of the novel pin-to-gear forming process. In this paper, the operating principle of the method is presented first of all. The new pin-to-gear process is then compared to conventional coining and the free-divided-flow (FDF) process developed at IFU Stuttgart in 2018. This examination takes the form of a numerical simulation using DEFORM-2D software. To investigate the influence of preform parameters on the form filling of the tooth cavities, parameter studies in design and geometry are conducted. Process limits regarding geometric constraints are presented alongside possibilities for increasing process reliability. Through this investigation, the potential and opportunities of the innovative pin-to-gear forming process will be illustrated.

A vasalóerő átlagos felületi érdességre gyakorolt hatásának modellezése

Egy gépelem kifáradás elleni ellenállása annál nagyobb, minél kevesebb makroszerkezeti változást és belső inhomogenitást tartalmaz. Élettartam szempontjából meghatározó továbbá a kedvező a feszültségállapot és a kisebb felületi érdessége is. Publikációnk az érdességet hatékonyan csökkentő vasalási megmunkálás során beállított erő átlagos felületi érdességre gyakorolt hatásával, illetve annak végeselemes modellezésével foglalkozik. A folyamat szimulációja DEFORM-2D szoftver alkalmazásával készül, megfelelve a gyakorlatban megvalósított vasalási paraméterek (vasalási erő, előtolás, sebessé) számszerű értékeinek is, ezáltal lehetővé téve egy összehasonlító elemzést gyengén ötvözött alumínium anyagminőség esetén.

A felületvasalási eljárás vizsgálata végeselemes módszerrel

Jelen tanulmány alumíniumötvözeten végzett hideg képlékeny gyémántszerszámos felületvasalás véges elemes vizsgálatát tárgyalja, mely során bemenő paraméterként a vasalási erő, előtolás és sebesség értéke került meghatározásra, míg kimenő paraméterként a felületi érdesség változását analizáljuk. Ez az élettartamnövelő eljárás hatékonyan csökkenti az érdességet, javítja az alakhibát, illetve növeli a felületközeli réteg keménységét. A vasalást megelőző esztergált felület megmunkálási szimulációja a fizikailag megvalósult, mért értékeknek megfelelően történik DEFORM-2D szoftver alkalmazásával, annak érdekében, hogy a bekövetkező felületminőség-javulást számszerű értékekkel is validáljuk.

Computer Simulation of the Direct Pressing Process Through Various Matrix Funnel Profiles

The stressed and deformed state of the metal and the dimensions of the center of deformation during pressing depend significantly on the design of the tool and, in particular, on the shape of the matrix funnel. However, there is still no single point of view on the influence of the geometry of the deformation center on the energy forces of the metal pressing process. Based on the analysis of the field of slip lines of the steady-state stage of pressing through a symmetric single-point matrix, it is proposed to use the profile of the matrix funnel made along the slip line separating the elastic and plastic zones. The following types of matrix funnel profiles were investigated using computer simulation of direct extrusion of lead samples with a drawing value 81 at a speed of 1 mm/s: cycloid concave; convex; the second convex, which is built on the logarithmic dependence; conical and concave, which is built along a sliding line that separates the elastic zones from the plastic in the pressing process. The results of theoretical studies, computer simulations of the direct pressing process using the Deform 2D/3D software package, and experimental experiments have shown that optimal energy-power conditions are achieved by pressing through a matrix that has a profile made along the slip line. The results of the experimental study of the kinetics of the flow of the discrete medium showed that the shape of the matrix funnel influences the size of the deformation center and the distribution of the resulting deformation in the molding. From the analysis of deformation of the granules, it is determined that the concave funnel, built along the slip line, is characterized by a curvature of the axisymmetric particles in the direction of deformation. These curvatures decrease as the granules move to the axis of symmetry of the matrix. It is noted that for a convex funnel, the length of the deformation center is greatest; for a conical metal flow is close to the radial in the direction of the truncated cones.