Effect of the Thickness of Dies for the Solidification Balance of Permanent Mould Casting AZ91D Magnesium Alloy

2009 ◽  
Vol 610-613 ◽  
pp. 750-753
Author(s):  
Jian Hua Zhao ◽  
Si Yuan Long ◽  
Hui Xu ◽  
Li Yan
Keyword(s):  
Numerical Simulation ◽  
Magnesium Alloy ◽  
Wall Thickness ◽  
Hot Spot ◽  
Experimental Results ◽  
Single Cycle ◽  
Chilling Effect ◽  
Az91d Magnesium Alloy ◽  
Mould Casting ◽  
Cooling Ability

The hot spot forming tendency during solidification of AZ91D magnesium alloy in permanent mould casting with the dies of different wall thickness via numerical simulation with Anycasting software was studied in the present paper. The experimental results showed that in a single cycle casting the increase in the thickness enhanced the cooling ability of the mould and promoted balanced solidification in a certain degree, while in multi-cycle casting, the thickened die-wall gradually lose its localized chilling effect. In contrast, the die with a decreased wall thickness in a certain range was easier to achieve the desired solidification balance.

Numerical Simulation of Mould Filling in Rheo-Diecasting Process of Semi-Solid Magnesium Alloys

2006 ◽  
Vol 116-117 ◽  
pp. 554-557 ◽  
Author(s):  
Shu Sen Wu ◽  
Jun Wen Zhao ◽  
Li Wan ◽  
Jirong Luo
Keyword(s):  
Numerical Simulation ◽  
Magnesium Alloy ◽  
Computer Program ◽  
Magnesium Alloys ◽  
Experimental Results ◽  
Air Entrapment ◽  
Mould Filling ◽  
Slurry Flows ◽  
Semi Solid ◽  
Numeral Simulation

The mould-filling behavior of rheo-diecasting of semi-solid magnesium alloy and diecasting of liquid magnesium alloy has been simulated with the computer program of numerical simulation developed by the authors. Results show that, under the same diecasting conditions, the filling behavior of rheo-diecasting of semi-solid metals is similar to the liquid diecasting, but mould filling of semi-solid slurry is steadier, and the slurry flows into the mould in a state similar to lamellar flow. The air entrapment in semi-solid process is much smaller than that of liquid diecasting, and the castings made with semi-solid rheo-diecasting excel those with liquid diecasting in quality. Experimental results are in accord with the results of numeral simulation.

Numerical Simulation of Thixoforging of an AZ91D Magnesium Alloy Magazine Plate and Experimental Validation

2008 ◽  
Vol 141-143 ◽  
pp. 623-628 ◽  
Author(s):  
Ju Fu Jiang ◽  
Ying Wang ◽  
Zhi Ming Du ◽  
Shou Jing Luo
Keyword(s):  
Numerical Simulation ◽  
Magnesium Alloy ◽  
Experimental Validation ◽  
Equivalent Strain ◽  
Technological Parameters ◽  
Billet Temperature ◽  
Az91d Magnesium Alloy ◽  
Punch Velocity ◽  
Die Temperature ◽  
Semi Solid

In this paper, thixoforging of a magazine plate made of AZ91D magnesium alloy were investigated by means of numerical simulation and experiments. Numerical simulation results show that with increasing punch displacement, local bending, formation of a concave shell part and bulk plastic deformation occurs in billet continuously. Equivalent strain and stress increase and the temperature of the semi-solid billet decreases. When the temperature of the semi-solid billet or the die temperature is elevated, equivalent stain and stress decrease. Optimal technological parameters such as a billet temperature of 545°C, die temperature of 450°C and punch velocity of 15 mm/s were obtained by numerical simulation. Experimental results demonstrate that magazine plates with high mechanical properties such as tensile strength of 316.8 MPa, yield strength of 228.3 MPa and elongation of 12.6 % can be manufactured successfully when the optimal technological parameters selected according to the results of numerical simulation are applied.

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.

Numerical Simulation of Superplastic Forming of a Magnesium Alloy Part

2007 ◽  
Vol 551-552 ◽  
pp. 263-268
Author(s):  
Quan Lin Jin ◽  
Zhi Peng Zeng ◽  
Yan Shu Zhang
Keyword(s):  
Numerical Simulation ◽  
Magnesium Alloy ◽  
Dynamic Recrystallization ◽  
Grain Refinement ◽  
Superplastic Forming ◽  
Grain Boundary Sliding ◽  
Experimental Results ◽  
Forming Process ◽  
Boundary Sliding ◽  
Alloy Part

A numerical simulation of superplastic backward extrusion of a magnesium alloy part is presented in this paper. In fact, the simulated superplastic forming is not a pure superplastic forming because of the billet with coarse cylindrical grains. The forming may become a pure superplastic forming only after dynamic recrystallization and grain refinement appear and the grain boundary sliding has been the main deformation mechanism. In order to simulate the special forming process, a constitutive relation considering dynamic recrystallization and the multiform deform mechanism and the parameter identification of the constitutive relattion are studied. The program for simulation is able to predict the grain refinement and the transform between different deformation mechanisms. Finally the calculated results on the grain size and dynamic rerystallization are presented. A comparison between the calculated and the experimental results shows there is a good agreement between calculated results and experimental results.

Influence Law of Initial Reverse Bulging on Sheet Hydroforming Process

2017 ◽  
Vol 746 ◽  
pp. 99-107 ◽  
Author(s):  
Li Hui Lang ◽  
Quan Da Zhang
Keyword(s):  
Numerical Simulation ◽  
Wall Thickness ◽  
Reasonable Agreement ◽  
Experimental Results ◽  
Forming Limit ◽  
Technological Parameters ◽  
Sheet Hydroforming ◽  
Hydroforming Process

In order to investigating the effect of the combination of two technological parameters such as the initial bulging height and the initial bulging pressure on the sheet , the sheet hydroforming process was studied. Firstly, by using the method of numerical simulation, the sheet hydroforming process with and without the initial bulging were discussed; Secondly, the effect of both the initial bulging height and the initial bulging pressure which were based on the hydroforming with the initial bulging on the forming of the part was studied; Thirdly, the result of the simulation was verified in the experiment. It was found that when the initial bulging height is 3.75mm and the initial bulging pressure is 2MPa, the maximum thinning ratio of the sheet is 4.803% at the end of the sheet hydroforming process. According to the hydroforming process without the initial bulging factors, the maximum thinning ratio is 5.123%. It can be found that the initial bulging factors play a key role in the sheet hydroforming process. The maximum thinning ratio of the wall thickness can be decreased effectively by the appropriate initial bulging height and bulging pressure, and the forming limit can also be improved at the same time. The results of numerical simulation have a reasonable agreement with the experimental results.

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