Room Temperature Screw Form Rolling of AZ91D Magnesium Alloy through Processing by Extrusion-Torsion Simultaneous Working

2014 ◽  
Vol 783-786 ◽  
pp. 375-379
Author(s):  
Mitsuaki Furui ◽  
Shouyou Sakashita ◽  
Kazuya Shimojima ◽  
Tetsuo Aida ◽  
Kiyoshi Terayama ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Room Temperature ◽  
Hardness Measurement ◽  
Rolling Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Az91d Magnesium Alloy ◽  
Microstructure Observation ◽  
Fine Grain ◽  
Simultaneous Processing

Extrusion-torsion simultaneous processing is a very attractive technique for fabricating a rod-shape material with fine grain and random texture. We have proposed a new screw form rolling process combined with preliminary extrusion-torsion simultaneous working. Microstructure evolution and mechanical property change of AZ91D magnesium alloy during extrusion-torsion simultaneous processing was examined through microstructure observation, X-ray diffraction analysis and micro-Vickers hardness measurement. By the addition of torsion, the crystal orientation of AZ91D magnesium alloy workpiece was drastically changed from basal crystalline orientation to the random orientation. Crystal grain occurred through the dynamic recrystallization and tended to coarsen with an increase of extrusion-torsion temperature. Grain refinement under 2 um was achieved at the lowest extrusion-torsion temperature of 523 K. M8 gauge AZ91D magnesium alloy screw was successfully formed at room temperature using the extrusion-twisted workpiece preliminary solution treating at 678 K for 345.6 ks. It was found that the extrusion-torsion temperature of 678 K must be selected to fabricate the good screw without any defects.

Microstructure Evolution of a Fine Grain Al-50wt%Si Alloy Fabricated by High Energy Milling

2011 ◽  
Vol 479 ◽  
pp. 54-61 ◽  
Author(s):  
Fei Wang ◽  
Ya Ping Wang
Keyword(s):  
Grain Growth ◽  
Microstructure Evolution ◽  
Room Temperature ◽  
Milling Time ◽  
High Energy ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Laser Method ◽  
X Ray ◽  
Fine Grain

Microstructure evolution of high energy milled Al-50wt%Si alloy during heat treatment at different temperature was studied. Scanning electron microscope (SEM) and X-ray diffraction (XRD) results show that the size of the alloy powders decreased with increasing milling time. The observable coarsening of Si particles was not seen below 730°C in the high energy milled alloy, whereas, for the alloy prepared by mixed Al and Si powders, the grain growth occurred at 660°C. The activation energy for the grain growth of Si particles in the high energy milled alloy was determined as about 244 kJ/mol by the differential scanning calorimetry (DSC) data analysis. The size of Si particles in the hot pressed Al-50wt%Si alloy prepared by high energy milled powders was 5-30 m at 700°C, which was significantly reduced compared to that of the original Si powders. Thermal diffusivity of the hot pressed Al-50wt%Si alloy was 55 mm2/s at room temperature which was obtained by laser method.

Aging Property of AZ91D Magnesium Alloy Screw Thread-Rolled at Room Temperature Using Extrusion-Torsion Simultaneous Processing

2016 ◽  
Vol 879 ◽  
pp. 2450-2455
Author(s):  
Mitsuaki Furui ◽  
Shouyou Sakashita ◽  
Shougo Suzuki ◽  
Tetsuo Aida ◽  
Yuusuke Ishisaka ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Room Temperature ◽  
Aging Treatment ◽  
High Strength ◽  
Extrusion Process ◽  
Peak Hardness ◽  
Screw Thread ◽  
Az91d Magnesium Alloy ◽  
Simultaneous Processing ◽  
Aging Property

We have proposed a new extrusion process functionally combined with torsion. Extrusion-torsion simultaneous processing is a very attractive technique for fabricating a rod-shape material with high strength and excellent workability. To improve the hardness, the aging treatment was performed with AZ91D magnesium alloy screw thread-rolled at room temperature using extrusion-torsion simultaneous processing. The distribution of hardness from the tip to center in as thread-rolled screw was modified to uniform distribution by the isothermal aging treatment at 423 K for 460.8 ks. The peak hardness was not depended on the working temperature and rotation speed during extrusion-torsion simultaneous processing. β-Mg17Al12 precipitates are obviously grown in as peak-aged condition comparing with as thread-rolled condition.

Grain Refinement of AZ91D Magnesium Alloy by In Situ Al4C3 Particles

2011 ◽  
Vol 306-307 ◽  
pp. 429-432
Author(s):  
Hui Han ◽  
Hua Ming Miao ◽  
Sheng Fa Liu ◽  
Yang Chen
Keyword(s):  
Magnesium Alloy ◽  
Grain Refinement ◽  
Synthesis Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Az91d Magnesium Alloy ◽  
Average Grain Size ◽  
Central Regions ◽  
Heterogeneous Nucleus

Experiments were conducted to fabricate the Al4C3 particles by powder in-situ synthesis process under argon atmosphere and examine the grain refinement of AZ91D magnesium alloy with the addition of 0.6%Al4C3(hereafter in mass fraction,%). By means of X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS), the results show the successful fabrication of Al4C3 particles. After adding 0.6%Al4C3, the average grain size of AZ91D magnesium alloy decreased from 360μm to 243μm. Based on the differential thermal analysis (DTA) results and calculations of the planar disregistry between Al4C3 and α-Mg, Al4C3 particles located in the central regions of magnesium grains can act as the heterogeneous nucleus of primary α-Mg phase.

Laser Cladding of Zr55Al10Ni5Cu30/SiC Amorphous Composite Coatings on AZ91D Magnesium Alloy for Improvement of Corrosion Resistance

2011 ◽  
Vol 179-180 ◽  
pp. 757-761 ◽  
Author(s):  
Kai Jin Huang ◽  
Hou Guang Liu ◽  
Chang Rong Zhou
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Laser Cladding ◽  
Composite Coatings ◽  
Corrosion Property ◽  
Nacl Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Good Corrosion Resistance ◽  
Az91d Magnesium Alloy

To improve the corrosion property of magnesium alloys, Zr-based amorphous composite coatings have been fabricated on AZ91D magnesium alloy by laser cladding using mixed powders Zr55Al10Ni5Cu30/SiC. The microstructure of the coating was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The corrosion resistance of the coatings was tested in 3.5wt.% NaCl solution. The results show that the coatings mainly consist of amorphous and different crystalline phases. The coatings compared with AZ91D magnesium alloy exhibit good corrosion resistance because of the presence of the amorphous phase in the coatings.

Strengthening of CP-Ti by Rolling at Room Temperature

2010 ◽  
Vol 667-669 ◽  
pp. 737-741
Author(s):  
Jian Hua Jiang ◽  
Yi Ding ◽  
Ai Dang Shan
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Mechanical Test ◽  
Commercial Purity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transition Electron Microscopy ◽  
Microstructure Observation ◽  
Cp Ti ◽  
Transition Electron

The effects of asymmetric and symmetric rolling at room temperature on mechanical properties and microstructure of the commercial purity Ti were investigated by means of mechanical test, optical microscopy, X-ray diffraction and transition electron microscopy. The results show that through asymmetric and symmetric rolling processes the ultimate tensile strength is substantially increased from 450 MPa to 960 MPa. Microstructure observation illustrates this variation in mechanical property is caused by the grain refinement and work hardening.

Materials Development and Hardness Properties of Aluminum Alloy

2014 ◽  
Vol 575 ◽  
pp. 83-87
Author(s):  
Muhammad Husna Al Hasa ◽  
Masrukan ◽  
Arief Sasongko Adhi
Keyword(s):  
Aluminum Alloy ◽  
Rolling Process ◽  
Optical Microscope ◽  
Nuclear Industry ◽  
X Ray Diffraction ◽  
Alloy Plate ◽  
X Ray ◽  
Hardness Tester ◽  
Microstructure Observation ◽  
Rolling Deformation

This research aims to develop an aluminum alloy suitable for applications in the nuclear industry, particularly in terms of its hardness. A synthesized AlFeNiMg alloy plate was subjected to deformation in a gradual rolling process at room temperature. A Vickers hardness tester and an optical microscope were employed to analyze the hardness and to observe the microstructure of the aluminum alloy consecutively. Analyses of elements and phase structures were performed by EDS-SEM and X-ray diffraction. The result shows that the hardness of AlFeNiMg alloy increases along with the increase in rolling deformation. The alloy hardness increases from 88 HV to 113 HV, 135 HV, 153 HV and 165 HV at percent cold reduction of 30%, 53%, 65% and 88% consecutively. From the microstructure observation, the grains tend to get more elongated along with increasing rolling deformation. The pattern analysis of X-ray diffraction shows that there are two phases, namely α and θ (FeAl3).

Microstructure and Mechanical Responses of Extruded Magnesium Alloy Sheets with Lithium Addition

2015 ◽  
Vol 816 ◽  
pp. 504-509 ◽  
Author(s):  
Qing Shan Yang ◽  
Bin Jiang ◽  
Jun Jie He ◽  
Zheng Yuan Gao ◽  
Jia Hong Dai ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Room Temperature ◽  
Texture Evolution ◽  
Tensile Tests ◽  
Extrusion Ratio ◽  
Basal Texture ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mechanical Responses ◽  
Room Temperature Ductility

After 5% lithium was added to AZ31 magnesium alloy, the alloy was extruded at 380oC with the extrusion ratio of 101. Mechanical responses and microstructure evolution were investigated. The microstructure and texture evolution were examined by electronic backscattered diffraction (EBSD) and X-ray diffraction (XRD). Tensile tests in the tensile directions of 0o, 45oand 90owere carried out at room temperature. Lithium addition brought about the strong divergence of the grain orientation and triggered the spread of the (0002) basal texture. The room temperature ductility of the extruded Mg alloy sheets was improved due to the tilted weak basal texture.

Laser Cladding of Mg65Cu25Y10/SiC Amorphous Composite Coatings on AZ91D Magnesium Alloy for Improvement of Corrosion Resistance

2010 ◽  
Vol 143-144 ◽  
pp. 758-762
Author(s):  
Kai Jin Huang ◽  
Hou Guang Liu ◽  
Chang Rong Zhou
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Laser Cladding ◽  
Composite Coatings ◽  
Corrosion Property ◽  
Nacl Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Good Corrosion Resistance ◽  
Az91d Magnesium Alloy

To improve the corrosion property of magnesium alloys, Mg-based amorphous composite coatings have been fabricated on AZ91D magnesium alloy by laser cladding using mixed powders Mg65Cu25Y10/SiC. The microstructure of the coating was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The corrosion resistance of the coatings was tested in 3.5wt.% NaCl solution. The results show that the coatings mainly consist of amorphous and different crystalline phases. The coatings compared to AZ91D magnesium alloy exhibit good corrosion resistance because of the presence of the amorphous phase in the coatings.

Effect of Strain to the Microstructure and Texture of AZ31 Magnesium Alloy during Compression Deformation at Room Temperature

2014 ◽  
Vol 893 ◽  
pp. 387-391
Author(s):  
Shan Jiang ◽  
Bin Zeng ◽  
Lyes Douadji
Keyword(s):  
Magnesium Alloy ◽  
Room Temperature ◽  
Optical Microscope ◽  
Az31 Magnesium Alloy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Compression Direction ◽  
Different Strains ◽  
Strain Increase ◽  
Electronic Microscope

AZ31 magnesium alloy samples were compressed to different strains at room temperature and examined through the optical microscope, X-ray diffraction (XRD) and scanning electronic microscope. The results show that the produced twins were mainly the {102} type, and then the {101} type and {102}-{101} type. The size and amount of the twins increased with the strains growth, and after the saturation of twins in the grains the samples fractured. The compressed texture with the basal planes perpendicular to the compression direction also become stronger with strain increase. The {102} twinning deformation played an important role in changing the microstructure and properties of the magnesium alloy at room temperature.

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