Influence of Process Parameters on T-Shape Tube HydroForming Characteristics for Magnesium Alloy

2007 ◽  
Vol 364-366 ◽  
pp. 973-979
Author(s):  
Shen Yung Lin ◽  
C.M. Chang ◽  
C.K. Chang
Keyword(s):  
Magnesium Alloy ◽  
Strain Hardening ◽  
Process Parameters ◽  
Material Flow ◽  
Large Strain ◽  
Manufacturing Cost ◽  
Hydraulic Pressure ◽  
Influence Of Process Parameters ◽  
Forming Characteristics ◽  
Strain Hardening Rate

Due to the light weight and electromagnetic interference shielding capabilities in magnesium alloy material, it is widely utilized in 3C electronic components and automobile parts. However, its formability is very poor due to the phenomenon of negative strain hardening rate appearing as the deformation in large strain range, so it is usually formed as die casting or casting styles leads to much scrap, and manufacturing cost is thus increased. The objective of this study is to investigate the effect of process parameters on T-shape tube hydro-forming characteristics for magnesium alloy and it may offer the data resulting from the analysis to predict an acceptable product of tube fitting for magnesium alloy forming in industry. AZ31 magnesium alloy tube is used as the billet material for hydro-forming with hydraulic pressure as the main forming power combined with the mechanical auxiliary force from the punch to fabricate the T-shape tubing products. Finite element code DEFORM-3D is adopted to investigate the forming states of T-shape tube forming, by changing process parameters; such as punch velocity, hydraulic pressure, fillet radius of the die and tool-workpiece interface friction etc. to investigate the material flow of tube fitting, wall thickness variations, and stress and strain distributions. By qualifying the forming processes whether if it is completed or not, and synthesizing the overall analysis and judgment, we establish an admissible level of process parameter range for complete tube manufacture. The results show that suitable mechanical force can help material flow, prevent large strain deformation falling into the area of negative strain hardening rate, enhance magnesium alloy to become easy in forming and make tube fitting to be formed successfully.

Forming Rule Construction for Hourglass-Like Tube Hydroforming with Magnesium Alloy

2009 ◽  
Vol 628-629 ◽  
pp. 489-498
Author(s):  
Shen Yung Lin ◽  
C.M. Chang ◽  
Ruey Fang Shyu
Keyword(s):  
Magnesium Alloy ◽  
Material Flow ◽  
Large Strain ◽  
Tube Hydroforming ◽  
Quantitative Prediction ◽  
Hydraulic Pressure ◽  
Data Sets ◽  
Forming Characteristics ◽  
Tube Hydro Forming ◽  
Thickness Variations

The objective of this study is to construct the forming rule for hourglass-like tube with magnesium alloy during hydro-forming and offer the analysis results as a guideline for magnesium alloy forming in industry. AZ31 magnesium alloy circular tube is used as the billet material for hydro-forming with hydraulic pressure as the main forming power combined with the mechanical auxiliary force from the punch to fabricate the hourglass-like tubing products. A finite element based code is utilized to investigate the forming characteristics of hourglass-like tube forming, by changing process parameters such as punch velocity, hydraulic pressure gradient and tool-workpiece interface friction etc. to investigate the material flow of tube filling, wall thickness variations, and stress and strain distributions. And the abductive network is in turn applied to synthesize the data sets obtained from the numerical simulations. Consequently, a quantitative prediction model is developed for the relationships among the process variables, corner radius and minimum tube thickness in the process of hourglass-like tube hydro-forming with magnesium alloy. The results show that proper mechanical force can help material flow, prevent large strain deformation from falling into the area of negative strain hardening rate, enhance the magnesium alloy to become easy in forming and make tube fitting may to be formed successfully.

Construction of a Prediction Model for an Acceptable T-Shape Tube Product in Magnesium Alloy Hydro-Forming

2010 ◽  
Author(s):  
S. Y. Lin ◽  
C. M. Chang ◽  
R. F. Shyu
Keyword(s):  
Neural Network ◽  
Finite Element ◽  
Magnesium Alloy ◽  
Prediction Model ◽  
Process Parameters ◽  
Wall Thickness ◽  
Hydraulic Pressure ◽  
Tube Forming ◽  
Finite Element Software ◽  
Forming Characteristics

The finite element method in conjunction with abductive neural network is applied to predict an acceptable T-shape product of which the minimum wall thickness and the protrusion height being fulfilled the industrial demand in the magnesium alloy hydro-forming. AZ31 magnesium alloy circular tube is used as the billet material for hydro-forming with hydraulic pressure as the main forming power combined with the mechanically auxiliary force from the punch to fabricate a qualified T-shape tubing product. Finite element software is adopted to investigate the forming characteristics of T-shape tube forming, by changing process parameters such as punch velocity, hydraulic pressure, fillet radius of the die and tool-workpiece interface friction etc. to investigate the material flow of tube forming, and the variations of wall thickness and protrusion height. And the neural network method in turn is applied to synthesize the data sets obtained from the numerical simulations and a prediction model for an acceptable T-shape tube product in magnesium alloy hydro-forming is thus constructed. From the prediction model, a suitable range of the process parameters variation for producing those qualified T-shape tubes that may be accepted in industrial applications can thus be identified.

The Influence of Die Geometry on the Radial Extrusion Processes with AA 6063 Aluminium Alloy

2006 ◽  
Vol 519-521 ◽  
pp. 937-942
Author(s):  
Dong Hwan Jang ◽  
J.H. Ok ◽  
H.S. Koo ◽  
G.M. Lee ◽  
Beong Bok Hwang
Keyword(s):  
Process Parameters ◽  
Material Flow ◽  
Deformation Pattern ◽  
Relative Deformation ◽  
Die Geometry ◽  
Single Action ◽  
Pressing Process ◽  
Major Process ◽  
Forming Characteristics ◽  
Gap Height

The rigid-plastic finite element method has been applied to three variants of radial extrusion processes to investigate the influence of die geometry on the material flow into the flange gap. Case I involves forcing a cylindrical billet against a flat die, which is a single action pressing process. In case II, another single action pressing process, the upper punch forces a billet against a stationary punch recessed in the lower die. Both the upper and lower punches move together in Case III toward the center of billet at the same speed with a double action tool. Major process parameters are identified as the relative gap height and the die corner radius in constant relative deformation. The relative gap height is defined as the ratio of gap height to billet diameter. Extensive simulation work for various combinations of process parameter value has been performed and then the main characteristics of the deformation patterns of each case are observed to define the terms which represent the forming characteristics of the flange in radial extrusion processes in terms of separation height, asymmetric ratio of height, and asymmetric ratio of angle, respectively. The effect of major process parameters on the material flow into the flange gap has been also analyzed in terms of flange radius and flange angle. The effect of frictional condition on the separation height has been also analyzed to investigate the edge separation of flange from the flat die. AA 6063 aluminum alloy is selected as a model material throughout the analysis. Simple comparison between AA 6063 and AISI 1006 steel has been also made to investigate the effect of material selection on the deformation pattern, especially in terms of separation height in Case I and asymmetry in Case II, respectively.

scholarly journals Forming and Properties of Friction Stir Welding Process for Dissimilar Mg Alloy

2015 ◽  
Vol 9 (1) ◽  
pp. 859-864
Author(s):  
Tielong Li ◽  
Zhenshan Wang
Keyword(s):  
Magnesium Alloy ◽  
Process Parameters ◽  
Welded Joints ◽  
Defect Formation ◽  
Base Material ◽  
Welding Process ◽  
Fracture Initiation ◽  
Line Defect ◽  
Influence Of Process Parameters ◽  
Friction Stir

For hot extrusions of magnesium alloy sheets, Dissimilar AZ80 and AZ31 were used, in which AZ80 was placed on advancing side and AZ31 on retreating side, using friction stir butt welding with different process parameters. Some defect-free welded joints with good weld surfaces could be obtained with some suitable welding conditions. The maximum tensile strength of welded joint which is 225.5 MPa can reach 98% that of the AZ31 base material. Influence of process parameters on defects, weld shaping and mechanical property were discussed systematically. And the microstructure of different zones was compared. The fracture of the welded joints takes place at the junction of mechanical heat affected zone and nugget zone in AZ31 magnesium alloy set retreating side, since existing difference in metallographic structure of alloy diversely suffered by heat, pressure and depositing impurities. Fracture initiation site may be the P line defect which should be eliminated, and the P line defect formation was analyzed.

Process Parameter Optimization for Better Hydro-Forming Performance of a Trailing Arm Tube

2013 ◽  
Vol 465-466 ◽  
pp. 704-708
Author(s):  
Shen Yung Lin ◽  
Hong Yi Liao
Keyword(s):  
Process Parameters ◽  
Wall Thickness ◽  
Tube Wall ◽  
Thickness Distribution ◽  
Equivalent Stress ◽  
Process Parameter ◽  
Hydraulic Pressure ◽  
Forming Process ◽  
Tube Wall Thickness ◽  
Forming Characteristics

This work presents the tube forming characteristics of a trailing arm which the whole forming processes are arranged through pre-bending twice and hydro-forming once. This work utilizes the finite element method to simulate the hydro-forming process of the trailing arm by changing the process parameters, such as velocity of left and right punches and internal hydraulic pressure, etc. The effects of process parameters on the distribution states of the tube wall-thickness, distribution of equivalent stresses and strains, and formability of the forming arm are thus investigated. Taguchi method, orthogonal array and factor response are then applied together to determine the optimal process parameter combinations corresponding to two single-quality objects, minimum tube wall-thickness and maximum equivalent stress, with nominal-the-best and smaller-the-better, respectively. It shows that the velocity of the right punch for the billet material axial feeding supplement should be larger than that of the left punch preventing the uneven bursting of the tube-wall on right-end. The analysis of variance also shows that left punch velocity is a major contribution parameter for tube wall-thickness while that primarily affects the equivalent stress is the internal pressure.

Press Forging of Magnesium Alloy AZ31 Sheets

2007 ◽  
Vol 539-543 ◽  
pp. 1753-1758 ◽  
Author(s):  
Shi Hong Zhang ◽  
Zhang Gang Li ◽  
Yong Chao Xu ◽  
Li Mei Ren ◽  
Zhong Tang Wang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Magnesium Alloy ◽  
Process Parameters ◽  
Material Flow ◽  
Friction Condition ◽  
Experimental Results ◽  
Alloy Az31 ◽  
Magnesium Alloy Az31 ◽  
Typical Component ◽  
Blank Size

Press forging of magnesium alloy AZ31 sheets was investigated in this paper. The typical component, a rectangular box with bosses at the bottom was formed. The experimental results show that the magnesium alloy sheets are suitable for press forging. The bosses and the rectangular box can be formed synchronously for 2 mm or 3 mm thick sheets when the punch temperature is 250 °C. By experimentation and numerical simulation, the effects of process parameters on material flow were analyzed, including the temperature, the die shape, the blank size, the lubrication manners and the friction condition.

Experimental and Numerical Analysis on FSWed Magnesium Alloy Thin Sheets Obtained Using “Pin” and “Pinless” Tool

2012 ◽  
Vol 504-506 ◽  
pp. 747-752 ◽  
Author(s):  
Gianluca Buffa ◽  
Archimede Forcellese ◽  
Livan Fratini ◽  
Michela Simoncini
Keyword(s):  
Magnesium Alloy ◽  
Process Parameters ◽  
Material Flow ◽  
Base Material ◽  
Welding Process ◽  
Welding Parameters ◽  
Thin Sheets ◽  
Tool Geometries ◽  
Shoulder Diameter ◽  
Strength And Ductility

The present investigation aims at studying the effect of different tool geometries and process parameters on FSW of thin sheets in AZ31 magnesium alloy. In particular two properly designed tools, with shoulder diameters equal to 8 and 19 mm, were used; each of them was manufactured both in pin and pinless configurations. The effect of the different tool configurations and sizes, and welding parameters on mechanical properties of FSWed joints were analyzed in detail. The results were compared with those obtained on the base material. It was shown that FSWed joints are characterized by strength and ductility values lower than those of base material. Furthermore, the pin tool configuration, with a shoulder diameter of 8 mm, leads to the obtaining of strength and ductility values higher than those provided by the pinless one. A strong beneficial effect is obtained by increasing the shoulder diameter from 8 to 19 mm using the pinless configuration, whilst the FSW with the pin tool is critically affected by the welding conditions. The experimental work was joined to a numerical investigation based on finite element method (FEM) in order to study the material flow occurring during the welding process as well as the distribution of temperature, with the aim to identify a input window of the process parameters within which sound joints can be obtained.

Study on the Dynamic Recrystallization Critical Stress of AZ91 Magnesium Alloy

2013 ◽  
Vol 477-478 ◽  
pp. 1269-1272
Author(s):  
Gang Chen ◽  
Shun Qi Zheng ◽  
Juan Lv ◽  
Zhin Min Zhang
Keyword(s):  
Magnesium Alloy ◽  
Strain Hardening ◽  
Critical Stress ◽  
Strain Rate Range ◽  
Test Machine ◽  
Strain Rates ◽  
Compression Tests ◽  
Az91 Magnesium Alloy ◽  
Az91 Magnesium ◽  
Strain Hardening Rate

The true stress-strain curves of AZ91 magnesium alloy as-homogenized were studied with compression tests on Gleeble 3500 thermal simulated test machine at 200°C—400°C and strain rate range of 10-3S-1 — 5S-1. Critical recrystallization behavior of AZ91 magnesium alloy was investigated by using strain hardening rate. The relationship between critical stress of dynamic revrystallization and temperatures and strain rates is determined by the curves between strain hardening rate and flow stress. According to the irreversible principles of thermo dynamics, the critical stresses at different temperatures and strain rates are calculated by two derivative of θ—σ curves. The map of the critical stress-temperatures-strain rates is established.

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