An Experimental Investigation on Semi-Solid Forming of Micro/Meso-Scale Features

2006 ◽  
Vol 129 (2) ◽  
pp. 246-251 ◽  
Author(s):  
Gap-Yong Kim ◽  
Jun Ni ◽  
Rhett Mayor ◽  
Heesool Kim
Keyword(s):  
Material Flow ◽  
Optical Measurement ◽  
Solid Material ◽  
Complex Interaction ◽  
Experimental Setup ◽  
Forming Process ◽  
Die Filling ◽  
Forming Technology ◽  
Semi Solid ◽  
Meso Scale

The potentials of semi-solid forming technology have generated much interest regarding its application in micromanufacturing. This study investigates the feasibility of using semi-solid forming technology to produce parts with micro/meso features. An experimental setup has been developed to study the effects of die/punch temperature, initial solid fraction, punch speed, and workpiece shape on the semi-solid forming process. A part has been produced for a microreactor application and has been analyzed with an optical measurement system for feature formation. The results indicated complex interaction among the process parameters and the material flow, which affected the final pin formation. The punch temperature and velocity had a significant effect on the overall die filling. The initial workpiece shape and solidification of the semi-solid material during forming influenced the micro/meso-feature formation sequence, affecting the final pin formation. Furthermore, grain deformation and distribution of the formed parts were investigated. The grains became larger due to induction heating and the forming process. Severely distorted grains were observed at the corner regions of the pins and the punch-workpiece interface.

Experimental Research on the Semi-Solid Formability of 7A09 Aluminum Alloy Impeller

2011 ◽  
Vol 189-193 ◽  
pp. 3852-3856
Author(s):  
Fei Han ◽  
Wei Wei Wang ◽  
Shou Jing Luo ◽  
Zhi Ming Du
Keyword(s):  
Heating Temperature ◽  
Hydraulic Press ◽  
Holding Time ◽  
Forming Process ◽  
Forming Technology ◽  
Preheating Temperature ◽  
Complicated Geometry ◽  
Semi Solid ◽  
Wrought Aluminum Alloys ◽  
Wrought Aluminum

The impeller is an important component applied in airplanes, ships and weapons. It is difficult to form the complicated geometry of the impeller by using the conventional forging and casting technology. Semi-solid forming is a promising forming process that can produce complicated and high-quality components of wrought aluminum alloys. In this paper, the formability of the impeller was investigated by using advanced semi-solid forming technology and self-designed combined die, as well as quick forging hydraulic press. Experimental results show that the formability of the impeller increases with the increase of reheating temperature and holding time of the billet. When heating temperature and holding time during the pretreatment of the billet were 620°C and 25 min respectively, reheating temperature and holding time of the billet before thixoforging were 600°C and 90 min respectively, preheating temperature of the die was 320°C , the impeller was formed perfectly on the quick forging hydraulic press.

Numerical Simulation on Thixocasting Process of Auto Box-Like

2011 ◽  
Vol 341-342 ◽  
pp. 177-182 ◽  
Author(s):  
Van Luu Dao ◽  
Sheng Dun Zhao ◽  
Wen Jie Lin ◽  
Yu Qiu Chen
Keyword(s):  
Main Process ◽  
Forming Process ◽  
Billet Temperature ◽  
Forming Technology ◽  
Initial Billet ◽  
Near Net Shape ◽  
Net Shape Forming ◽  
Ram Speed ◽  
Semi Solid ◽  
The Impact

Semi-solid metal processing (thixoforming) is a potential forming technology, which can realize near-net-shape forming process with good quality in one forming step. In this study, semi-solid casting (thixocasting) was used to form the auto box-like. Based on Power Law Cut-Off (PLCO) model and finite element code Procast software, the thixocasting process was modeled and simulated. The impact of main process parameters such as initial billet temperature, ram speed as well as die temperature on the thixocasting process was studied. The results show that thixocasting process can be used in forming auto box-like.

Process Window Determination for Thixoextrusion Processes Using a Steel Alloy

2008 ◽  
Vol 141-143 ◽  
pp. 61-66
Author(s):  
Frederik Knauf ◽  
René Baadjou ◽  
Gerhard Hirt
Keyword(s):  
Material Flow ◽  
Solid Material ◽  
Extrusion Process ◽  
Process Window ◽  
Steel Alloy ◽  
Channel Diameter ◽  
Feed Stock ◽  
Temperature Development ◽  
Process Mechanics ◽  
Semi Solid

A direct semi-solid bar extrusion process is characterised by inserting a feed stock in a container and extruding through a forming die with a punch. Compared to conventional bar extrusion the use of semi-solid material complicates the process due to the requirement of solidification of the material. To achieve the solidification of the semi-solid bar, different basic tool concepts are presented. With a combination of these concepts experiments were carried out using the steel alloy X210CrW12 to detect the influence of the most influencing parameters press velocity, extrusion channel diameter, length and geometry. Numerical simulations enable a better understanding of the process mechanics like temperature development in the billet and forming die as well as the material flow in the deformation zone.

Joining of carbon fibres with aluminium structures – Processing and infiltration modelling

2020 ◽  
Vol 54 (25) ◽  
pp. 3767-3775
Author(s):  
Lukas Marx ◽  
Mathias Liewald
Keyword(s):  
Metal Forming ◽  
Lightweight Design ◽  
Solid Material ◽  
Carbon Fibres ◽  
Carbon Fabric ◽  
Infiltration Process ◽  
Forming Technology ◽  
Material State ◽  
Aluminium Sheets ◽  
Semi Solid

Against the background of today's lightweight design, an innovative joining technique has been developed at the Institute for Metal Forming Technology/Stuttgart for combining aluminium sheet structures with carbon fabrics. During the process of Joining of Carbon Fibres with Aluminium Structures (JOCA process), two or more aluminium sheets with carbon fabric layers in-between are initially conductively heated up into the semi-solid material state by means of two adjacent electrodes of a welding gun. If heated up to a liquid share of 30% to 60%, the aluminium matrix infiltrates the carbon fabric resulting into a firm joint after solidification of the metal material. This publication provides an overview of the research results obtained by experimental and numerical investigations of the infiltration process achieved so far.

Production of Titanium Alloy Components by Semi-Solid Forming

2012 ◽  
Vol 192-193 ◽  
pp. 515-520 ◽  
Author(s):  
Levente Kertesz ◽  
Mathias Liewald
Keyword(s):  
Mechanical Properties ◽  
Metal Forming ◽  
Medical Engineering ◽  
High Variability ◽  
Development Work ◽  
Forming Process ◽  
Forming Technology ◽  
Semi Solid ◽  
New Research ◽  
The University

The relatively high costs of processing titanium alloys and the high variability in the products' quality currently represent the major economic obstacles to using such materials in either production or medical engineering. For this reason, new research and development work at the Institute for Metal Forming Technology of the University of Stuttgart is pursuing the objective of improving and enhancing pre-existing processes for these types of materials. In doing this, aspects are considered which specify definite mechanical properties during and after the forming process as well as reduce the costs by means of cutting the manufacturing times, increase the use of semi-finished products and minimise finishing operations.

Modeling of the Semi-Solid Material Behavior and Analysis of Micro-/Mesoscale Feature Forming

2006 ◽  
Vol 129 (2) ◽  
pp. 237-245 ◽  
Author(s):  
Gap-Yong Kim ◽  
Muammer Koç ◽  
Rhet Mayor ◽  
Jun Ni
Keyword(s):  
Solid Fraction ◽  
A356 Alloy ◽  
Structural Evolution ◽  
Solid Material ◽  
Material Behavior ◽  
Flow Rule ◽  
Stress Model ◽  
Forming Process ◽  
Mesoscale Feature ◽  
Semi Solid

One of the major challenges in simulation of semi-solid forming is characterizing the complex behavior of a material that consists of both solid and liquid phases. In this study, a material model for an A356 alloy in a semi-solid state has been developed for high solid fractions (>0.6) and implemented into a finite element simulation tool to investigate the micro-/mesoscale feature formation during the forming process. Compared to previous stress models, which are limited to expressing the stress dependency on only the strain rate and the temperature (or the solid fraction), the proposed stress model adds the capability of describing the semi-solid material behavior in terms of strain and structural evolution. The proposed stress model was able to explain the strain-softening behavior of the semi-solid material. Furthermore, a simulation model that includes the yield function, the flow rule, and the stress model has been developed and utilized to investigate the effects of various process parameters, including analysis type (isothermal vs nonisothermal), punch velocity, initial solid fraction, and workpiece shape (“flat” versus “tall”) on the micro-/mesofeature formation process.

Theoretical Analysis of Plastic Forming Process for Semi-Solid Material

2005 ◽  
Vol 488-489 ◽  
pp. 389-392 ◽  
Author(s):  
Hong Yan ◽  
Juchen Xei
Keyword(s):  
Magnesium Alloy ◽  
Upper Bound ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Normal Component ◽  
Solid Material ◽  
Tangential Component ◽  
Forming Process ◽  
Plastic Forming ◽  
Semi Solid

The plastic forming of magnesium alloy is difficult, but the semi-solid material forming is a good method solved this problem. The mechanical model of the semi-solid materials was treated as that of the continuous porous materials in the high solid volume fraction. The upper bound theory applied for semi-solid metal plastic forming process was developed. The velocity discontinuities exist not only in the tangential component but also in normal component for the kinematically admissible displacement increment filed. The latter one was responsible for a change in solid volume fraction when the material passes the discontinuity. An upper bound analytical model and theoretical method of plastic forming process for semi-solid material has been proposed. The calculating formulas of deformed power were derived. It is theoretical basement to apply further for the practice technology analysis such as the plastic forming of magnesium alloy.

Basic Investigations on Joining of Metal and Fibre Components Based on the Semi-Solid Forming Process

2015 ◽  
Vol 651-653 ◽  
pp. 1445-1450 ◽  
Author(s):  
Lukas Marx ◽  
Mathias Liewald ◽  
Kim Rouven Riedmüller
Keyword(s):  
Research Work ◽  
Textile Fibre ◽  
Forming Process ◽  
Forming Technology ◽  
New Material ◽  
New Type ◽  
Semi Solid ◽  
Cleaning Methods ◽  
Joining Process ◽  
Adhesive Materials

The trend towards lightweight construction in automotive engineering causes additional effort and higher expense in vehicle manufacturing, because new materials or, respectively, new material combinations require adapted production and processing methods. Various combinations of metallic and fibre-based structures (GRP-/ CFRP components) presuppose convenient joining methods. In this context, an innovative joining method for combining sheet metals with carbon textiles is going to be developed at the Institute for Metal Forming Technology (IFU, University of Stuttgart / Germany). The goal of this research work is motivated by the prevention of any damage of the used textile fibre structures during the joining process (compared to mechanical joining methods like screwing or riveting). Based on the semi-solid forming technology, the new joining process is going to be developed to create a material integrated interlock between fibres and metallic components.This paper deals with the first fundamental investigations, conducted at IFU, which have already shown the technical feasibility of this new type of joining technique. The research work to be carried out comprises the usage of different sheet alloys: the combinations steel-aluminium, aluminium-aluminium and steel-steel are to be joined with layers of carbon fibre fabrics. By this innovative joining method, a firmly bonded and non-aging connection between textile and metallic materials is to be produced, without the need of any adhesive materials or associated preparative cleaning methods.

Investigation of the Influence of a Superimposed Oscillated Forming Process on Forming Characteristics

2021 ◽  
Vol 883 ◽  
pp. 181-186
Author(s):  
Philipp Müller ◽  
Sven Hübner ◽  
Daniel Rosenbusch ◽  
Hendrik Vogt ◽  
Bernd Arno Behrens
Keyword(s):  
Surface Quality ◽  
Sheet Metal ◽  
Material Flow ◽  
New Technologies ◽  
High Surface ◽  
Efficient Production ◽  
Forming Process ◽  
Forming Technology ◽  
Forming Characteristics ◽  
Functional Components

The increasing demand for resource-efficient production methods is driving the development of new technologies. Sheet bulk metal forming (SBMF) offers the possibility to combine sheet metal and bulk forming operations. This allows the production of complex functional components with secondary forming elements from sheet metal. Compared to other production techniques such as machining, a more efficient use of material can be achieved. Further advantages are a near net shape production and increased strain hardening. SBMF processes are limited by forming technology boundaries. These include high forming forces, incomplete mould fillings and limited surface qualities. In this research, the possibility of enhancing the material flow, improving surface quality and reducing the tool loads in SBMF-processes is investigated by using a superimposed oscillation. The focus here is on achieving a high surface quality of components produced by forming technology and an enhanced material flow during forming. For this purpose, a forming process for ironing an axial gear geometry is superimposed with an oscillation in the main force flow.

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