Effect of Injection Speed on Microstructure of AZ91D Magnesium Alloy in Semi-Solid Injection Process

2012 ◽  
Vol 53 (6) ◽  
pp. 1094-1099 ◽  
Author(s):  
Yuichiro Murakami ◽  
Naoki Omura ◽  
Mingjun Li ◽  
Takuya Tamura ◽  
Kenji Miwa
Keyword(s):  
Magnesium Alloy ◽  
Injection Speed ◽  
Az91d Magnesium Alloy ◽  
Injection Process ◽  
Semi Solid

Effect of Volume Fraction Solid and Injection Speed on Mechanical Properties in New Type Semi-Solid Injection Process

2008 ◽  
Vol 141-143 ◽  
pp. 761-766 ◽  
Author(s):  
Naoki Omura ◽  
Yuichiro Murakami ◽  
Ming Jun Li ◽  
Takuya Tamura ◽  
Kenji Miwa
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Volume Fraction ◽  
Testing Machine ◽  
Permanent Mold ◽  
Injection Speed ◽  
Injection Process ◽  
Fraction Solid ◽  
New Type ◽  
Semi Solid

We have developed new type semi-solid injection process, that is, runner-less injection process which can obtain high material yield of about 90% for magnesium alloy. In this process, alloy billets are heated to the semi-solid temperature in the injection cylinder and are injected into a permanent mold. In order to investigate the effects of volume fraction solid and injection speed on microstructure and mechanical properties of AZ91D magnesium alloy injected into the permanent mold, semi-solid forming testing machine which has the same system as a runner-less injection machine, has been made on an experimental basis. The magnesium billet precisely controlled at given temperature has been injected into a permanent mold with two kinds (slow and high) of speed and plate-like specimens with each fraction solid have been fabricated. Microstructure has been observed by optical microscopy and X-ray computerized tomography (CT) scanner. Mechanical properties have been measured by tensile test. The effects of volume fraction solid of the alloy slurry and injection speed on mechanical properties have been clarified.

Microstructure Evaluate System of Semi-Solid Forming

2007 ◽  
Vol 546-549 ◽  
pp. 93-96 ◽  
Author(s):  
Xiao Peng Cui ◽  
Yong Bing Liu ◽  
Zhan Yi Cao ◽  
You Fa Zhang ◽  
Qian Qian Zhang
Keyword(s):  
Magnesium Alloy ◽  
The Other ◽  
Microstructure Analysis ◽  
Analysis Software ◽  
Az91d Magnesium Alloy ◽  
Alloy Microstructure ◽  
Semi Solid

The evaluating rules for semi-solid microstructure were brought up, and the analysis software was developed on MATLAB 7.0 platform in this study. Furthermore, this system can be used not only in the Thixomolding AZ91D magnesium alloy microstructure analysis, but also in the other semi-solid processing microstructure.

Study on Semi-Solid Continuous Roll-Casting Strips of AZ91D Magnesium Alloy

2008 ◽  
pp. 469-473
Author(s):  
Shui Sheng Xie ◽  
You Feng He ◽  
Guo Jie Huang ◽  
Mao Peng Geng ◽  
Ying Zhang
Keyword(s):  
Magnesium Alloy ◽  
Az91d Magnesium Alloy ◽  
Roll Casting ◽  
Semi Solid

scholarly journals Semi-solid forming of strain-induced AZ91D magnesium alloy.

1995 ◽  
Vol 45 (10) ◽  
pp. 560-565 ◽  
Author(s):  
Kazutoshi SEKIHARA ◽  
Satoshi OHNISHI ◽  
Shigeharu KAMADO ◽  
Yo KOJIMA
Keyword(s):  
Magnesium Alloy ◽  
Az91d Magnesium Alloy ◽  
Semi Solid

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.

Development of New Type Semi-Solid Injection Process for Magnesium Alloy

2014 ◽  
Vol 217-218 ◽  
pp. 361-365
Author(s):  
Yuichiro Murakami ◽  
Kenji Miwa ◽  
Naoki Omura ◽  
Shuji Tada
Keyword(s):  
Magnesium Alloy ◽  
Volume Fraction ◽  
Solid Particles ◽  
Casting Defects ◽  
Microstructure Observation ◽  
Injection Process ◽  
Fraction Solid ◽  
The Matrix ◽  
New Type ◽  
Semi Solid

We have developed new type semi-solid injection process for magnesium alloy. This process does not require to use any cover gases and the special magnesium billet such as thixo-billet. In this study, plate specimens were produced by injecting the semi-solid billet with different fraction solid. The microstructure observation, detection of casting defects by an X-ray computed tomography scanner, and tensile test were carried out. With increasing fraction solid, the size and shape of α-Mg solid particles became smaller and more spherical. In the condition of low fraction solid or forming in liquid state, the casting defects were located in the center of the specimen at the thickness direction. Additionally, the volume fraction of the casting defect decreased with increasing fraction solid. Moreover, the casting defects can be reduced by preventing solidifying and clogging of the top of the nozzle. Then, the specimen which has few casting defects could be obtained by injecting the slurry of fraction solid 0.5. However, the tensile strength and yield strength were highest in fraction solid 0.4. It is contemplated that the composition of the solid solution component element in the matrix was increased in fraction solid of 50%, therefore the matrix became brittle.

Study on Static Shear-Rheologic Characteristics of Semi-Solid AZ91D Magnesium Alloy by Reheating

2006 ◽  
Vol 116-117 ◽  
pp. 738-741
Author(s):  
Ze Sheng Ji ◽  
Mao Liang Hu ◽  
Xiao Ping Zheng
Keyword(s):  
Shear Stress ◽  
Magnesium Alloy ◽  
Critical Shear Stress ◽  
Critical Value ◽  
Holding Time ◽  
Az91d Magnesium Alloy ◽  
Coarse Grains ◽  
Small Grains ◽  
Semi Solid ◽  
Static Shear

Static shear-rheology for self-made semi-solid AZ91D magnesium alloy slurry was studied by using the tester and a universal electronic machine. Shear-stress along with cylindrical surface in the sample was produced by using the tester and then shear-rheologic deformation happened. It showed that on the condition of the same loading, the longer the loading time and holding time were, the larger the deforming rate was. When the holding time attained a certain value, small grains acquired enough energy to grow up or amalgamate with prolonging the holding time and coarse grains started to melt from intergranular or grain boundaries, but the critical shear-stress kept a constant. The sample didn’t flow but appeared to instantaneous shear-strains with starting to load. When the loading exceeded the critical value, the sample started to flow and had the phenomena of elastic after-working, elastic before-working and remained deformation. The rheologic characteristics of semi-solid AZ91D magnesium alloy were expressed by the five element mechanical model: H1—(N1/H2)—(N2/S).

Sign in / Sign up

Export Citation Format

Share Document