On the Balance of the Metal Flow in Porthole Dies with Differently Sized Porthole Channels

2013 ◽  
Vol 585 ◽  
pp. 77-84 ◽  
Author(s):  
Henry Sigvart Valberg ◽  
Dirk Nolte ◽  
Yawar Abbas Khan
Keyword(s):  
Metal Flow ◽  
Fe Analysis ◽  
Grid Pattern ◽  
Fem Model ◽  
Unequal Size ◽  
Flow Through

The relative balance between the metal flow in two portholes in extrusion has been investigated by experiments and FE-analysis. The investigation deals with asymmetric extrusion, i.e., the billet is extruded through a die with portholes of unequal size. Metal flow has been characterized by an experimental grid pattern technique. An optimized FEM-model of the experiment has been built and the experimental metal flow is found to be mimicked accurately by this model. The velocity conditions in the two differently sized ports feeding material into the weld chamber, and further from here into the extrudate, have been investigated to see if the balance between the flow through the two channels changes as extrusion proceeds. Increasing asymmetri between the two portholes has been realized in the analysis by displacement of the die bridge laterally in relation to the direction of extrusion.

Aluminium Extrusion Weld Formation and Metal Flow Analysis in Hollow Profile Extrusions of Different Section Thickness

2011 ◽  
Vol 491 ◽  
pp. 105-112 ◽  
Author(s):  
Yawar Abbas Khan ◽  
Henry Sigvart Valberg
Keyword(s):  
Wall Thickness ◽  
Perfect Match ◽  
Metal Flow ◽  
Extrusion Process ◽  
Experimental Results ◽  
Fe Model ◽  
Grid Pattern ◽  
Element Analysis ◽  
Weld Formation ◽  
Flow Through

Hollow and semi-hollow profiles are commonly produced by extrusion using porthole dies. The main characteristics of such dies are the presence of a mandrel (core) to shape the inner contour of hollow profile and bridges or legs to carry the mandrel. The bridges split the billet material into multiple metal streams that flow through the porthole channels and meet in the welding chamber behind the bridge where they are joined by pressure welding. When hollow profiles with different wall thickness are made the size of two adjacent portholes may be different. The material then flows through the two portholes with different flow velocity so that there is more feed through the bigger porthole into the weld chamber behind the bridge. Experiments have been performed and are reported here in which a grid pattern technique was used to characterize the metal flow through a 2D-die with porthole channels of unequal size. The design of the laboratory die has been modified in relation to the symmetric case to get different sizes of the two portholes. Since the metal flow through such a die is asymmetric the grid pattern technique was also modified to characterize the experimental flow. The results of an experimental metal flow study performed for a short billet was presented in a previous article [1]. Corresponding experiments performed with longer billets are now reported; so that two stages of the extrusion process is analysed here. The grid pattern technique has successfully mapped the non-symmetric material flow as in industrial extrusion when using different wall thickness over the section. The lateral movement of metal during extrusion is obtained from one set of experiments; the vertical movement from the other set. Finite element analysis of the extrusion process has been performed using Deform 3D. The encountering of the two metal streams behind the die bridge and the deformation characteristics within the welding chamber has been studied this way. Extrusion weld formation and deformations around the die bridge are considered here with the help of experimental results and simulation models. The nature of the metal flow achieved from the FE-model is compared with the experimental results. As regards the short billet some results are presented in [1], however improvement to the previous model gives a more perfect match. The model also provides information about the boundary conditions in real extrusion.

Analysis of Metal Flow of Aluminum through Long Choked Die Channels

2009 ◽  
Vol 424 ◽  
pp. 145-152 ◽  
Author(s):  
Henry Sigvart Valberg
Keyword(s):  
Cross Section ◽  
Channel Wall ◽  
Metal Flow ◽  
Extrusion Process ◽  
Sliding Contact ◽  
Aluminum Extrusion ◽  
Grid Pattern ◽  
Contact Conditions ◽  
New Knowledge ◽  
Flow Through

The mechanics of metal flow through long choked die channels have been investigated in unlubricated hot aluminum extrusion. Experiments were performed in a laboratory press at an earlier occasion by letting a grid pattern introduced into the billet flow down into the choked die channel to appear adjacent to the channel wall. The grid pattern was then revealed to characterize the metal flow in the channel. A 2D-model of the extrusion process was made. The model was applied to study the conditions in the extrusion experiments and in this model good similarity was obtained with the experiment. New knowledge regarding the metal flow through a choked die channel have been obtained this way, such as; contact conditions, presence of sticking and sliding zones, friction conditions in the sliding contact zone and the velocity profile over the cross-section of the channel.

scholarly journals Molten metal flow through multiple gates in the runner of die casting.

1986 ◽  
Vol 36 (9) ◽  
pp. 577-581
Author(s):  
Yasushi IWATA ◽  
Yoshiaki YAMAMOTO ◽  
Motoshi NAKAMURA ◽  
Haruo SUZUKI ◽  
Hiroshi SAWADA ◽  
...  
Keyword(s):  
Molten Metal ◽  
Die Casting ◽  
Metal Flow ◽  
Flow Through ◽  
Molten Metal Flow

Experiment and FE Analysis of Compression of Thick Ring Filled with Oil

2018 ◽  
Vol 767 ◽  
pp. 141-148
Author(s):  
Yoshiki Tatematsu ◽  
Mitsuka Morimoto ◽  
Kazuhiko Kitamura
Keyword(s):  
Weight Reduction ◽  
High Strength Steel ◽  
Metal Flow ◽  
High Strength ◽  
Fe Analysis ◽  
Inner Diameter ◽  
Save Energy ◽  
The Ideal

Reducing automobile weight has been necessarily accelerated to save energy and improve drivability. Accordingly, use of high strength steel and hollow sections help in weight reduction. In this study, the effect of trapped oil has been investigated to improve the metal flow in upsetting of a hollow workpiece using no mandrel. It was found that the ideal deformation without friction between the dies and the workpiece was nearly achieved when a low and thick ring with trapped oil was upset. The inner diameter of the oil-filled ring was expanded more than that of the benchmark ring. The effect of the expansion of the ring and the reduction of the friction proved helpful in trial forming of a gear preform.

INVESTIGATIONS OF LIQUID METAL FLOW THROUGH A RIGHT ANGLE BEND UNDER FUSION RELEVANT CONDITIONS

1993 ◽  
pp. 1276-1280 ◽  
Author(s):  
L. Barleon ◽  
L. Bühler ◽  
K.J. Mack ◽  
S. Molokov ◽  
R. Stieglitz ◽  
...  
Keyword(s):  
Liquid Metal ◽  
Metal Flow ◽  
Liquid Metal Flow ◽  
Angle Bend ◽  
Flow Through

Analysis of MHD Pressure Drop in Packed Pebble Bed-Based Blanket for FDS

2013 ◽  
Author(s):  
Hongyan Wang ◽  
Chan Tang
Keyword(s):  
Pressure Drop ◽  
Liquid Metal ◽  
Analytical Model ◽  
Interaction Parameter ◽  
Metal Flow ◽  
Hybrid Reactor ◽  
Pebble Bed ◽  
Critical System ◽  
Liquid Metal Flow ◽  
Flow Through

The Fusion-Driven Sub-critical System as a multifunctional hybrid reactor has been investigated in ASIPP. The liquid metal LiPb flow through a packed pebble bed-based blanket is considered to be one of the blanket candidates. In this contribution, the Magnetohydrodynamics (MHD) pressure drop of liquid metal flow through the packed pebble bed has been calculated and analyzed under various conditions including (a) the size of the packed pebbles; (b) the ratio of occupied room by the packed pebbles to that of liquid metal; and (c) whether the pebbles surface is insulated or not. Furthermore, asymptotic techniques to analyze large Hartmann parameter flow and interaction parameter flow are employed and an analytical model has been developed for the calculations of MHD pressure drop of liquid metal flow in a packed pebble bed. The appropriate method for calculating the MHD effects on the pressure drop through the packed pebble bed-based blanket for the FDS has been presented.

scholarly journals Eulerian Description of Rail Straightening Process

2014 ◽  
Vol 624 ◽  
pp. 213-217 ◽  
Author(s):  
Tomas Návrat ◽  
Jindrich Petruška
Keyword(s):  
Numerical Analysis ◽  
Material Flow ◽  
Beam Element ◽  
Fe Analysis ◽  
Lagrangian Description ◽  
Element Formulation ◽  
Deformation Effect ◽  
Plastic Bending ◽  
Eulerian Description ◽  
Flow Through

The paper deals with numerical analysis of the process of roller straightening of rails. The problem of repeated elasto-plastic bending is solved by a program in MATLAB based on FEM algorithm with Eulerian description of material flow through the straightening machine. Beam element formulation with a shear deformation effect is used for the rail discretization. The results are compared with literature and standard FE analysis with Lagrangian description of material flow. Effectiveness of presented formulation is discussed and its applicability for fast iterative optimization of the straightening process is illustrated.

On the Fundamental Mechanism of Seam Welding in Extrusion of Aluminum Alloys

2012 ◽  
Vol 504-506 ◽  
pp. 529-534 ◽  
Author(s):  
Henry Valberg ◽  
Yawar Abbas Khan
Keyword(s):  
Pattern Analysis ◽  
Metal Flow ◽  
The Other ◽  
Deformation Mechanisms ◽  
Grid Pattern ◽  
Seam Welding ◽  
Extrusion Welding ◽  
Recent Advancement ◽  
Charge Weld ◽  
Fundamental Mechanism

In extrusion of hollow Al-profiles two kinds of pressure welds are present inside the extrusion. One is called the charge weld (CW) and forms across the boundary interface between two billets extruded in sequence. The other is the seam weld (SW) which extends longitudinally along the extruded profile and the extrusion metal behind each die bridge. It is considered to form because of the splitting of the extrusion metal over the die bridge into metal streams which flow past the bridge and rejoin as they encounter behind the bridge. Over the time attempts have been made to explain the mechanics of extrusion welding for both the CW and the SW. Still there is lack of understanding of how these welds form, the main reasons for this is that the deformation conditions around a die bridge are complex and difficult to investigate. Because of the recent advancement of two technological fields, experimental grid pattern analysis and simulation of metal flow by FEA; new tools for analysis of the mechanics of formation of the SW and the CW are now available. The simplest possible case of 2D-extrusion seam welding is considered here and an attempt is made to describe the fundamental deformation mechanisms present when this weld forms behind a butt-ended die bridge.

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