Researches on a Composite Extrusion Approach Based on FEM Method and Experiments

2011 ◽  
Vol 686 ◽  
pp. 305-309 ◽  
Author(s):  
Ding Fei Zhang ◽  
Jun Ping Zhang ◽  
Hong Jun Hu
Keyword(s):  
Mechanical Properties ◽  
Element Model ◽  
Az31 Alloy ◽  
Extrusion Ratio ◽  
Extrusion Force ◽  
Direct Extrusion ◽  
Fem Method ◽  
Shear Process ◽  
Different Temperatures ◽  
Microstructures And Mechanical Properties

This paper deals with a finite element model (FEM) for the extrusion of AZ31 alloy and extrusion experiments at different temperatures. The simulation is utilized to predict the extrusion force and strain at different temperatures. ES (extrusion-shear) process and direct extrusion are investigated at 370, 400 and 420°C to discuss the effects of different temperatures on the microstructures and mechanical properties with the extrusion ratio of 11.56. The simulation results obtained show that the extrusion force of ES process is much larger than direct extrusion because of the two corners. ES process could effectively refine the grains, especially the microstructure of the central region compared with direct extrusion. The bar extruded at 370°C shows the best microstructures and mechanical properties.

Effects of Extrusion–Shear Process Conditions on the Microstructures and Mechanical Properties of AZ31 Magnesium Alloy

2016 ◽  
Vol 35 (10) ◽  
pp. 967-972
Author(s):  
H.J. Hu ◽  
Y.Y. Li ◽  
X. Wang ◽  
D.F. Zhang ◽  
M.B. Yang
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Microstructure Analysis ◽  
Az31 Magnesium Alloy ◽  
Process Conditions ◽  
Compression Tests ◽  
Billet Temperature ◽  
Direct Extrusion ◽  
Shear Process ◽  
Microstructures And Mechanical Properties

AbstractIn this paper, the effects of extrusion–shear (ES) on the microstructures and mechanical properties of AZ31 magnesium alloy has been studied, which has been achieved by conducting a lot of experiments and tests, including ES process, direct extrusion with different billet temperatures, microstructure analysis, hardness test, tensile & compression tests. The results show that the ES-processed rods has higher strengths (yield strength and tensile strength) than the direct extrusion ones with the same billet temperature, which contributed to their lower averaged grain size obtained from microstructure analysis according to Hall–Petch relation. Besides, the hardness of ES-processed AZ31 magnesium alloy decreases with the increasing of billet temperature. By comparing the two processes, it can be seen that the ES process could refine the microstructure and improve the mechanical properties of magnesium alloy.

The Microstructures and Mechanical Properties of Hot-Processed Magnesium Casting Alloys

2006 ◽  
Vol 503-504 ◽  
pp. 775-780 ◽  
Author(s):  
Takeshi Yamaguchi ◽  
Tadayoshi Tsukeda ◽  
Ken Saito ◽  
Yoshihito Kawamura
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Extrusion Direction ◽  
High Strength ◽  
Extrusion Ratio ◽  
Extrusion Temperature ◽  
Tensile Yield Strength ◽  
Extrusion Force ◽  
Casting Alloys ◽  
Magnesium Casting

In order to make the effect of processing clear, AM50A magnesium casting alloys were extruded at various extrusion conditions such as extrusion temperature and extrusion ratio. The mechanical properties of AM50A alloy increased with decreasing extrusion temperature. Tensile yield strength and tensile strength of extruded AM50A alloy were 389MPa and 420MPa respectively when the extrusion temperature was 348K. The microstructure of the extruded magnesium alloy showed large grains stretched to the extrusion direction and fine recrystallized grains. Decreased extrusion temperature resulted in improved strength and decreased elongation with increasing of the degree of work hardens and extrusion force. When the extrusion ratio is high, improvement of strength is prevented by rycrystallization and it was observed as crystal orientation by XRD. The elongation of the extrusion increased with the recrystallization of grains. Every magnesium alloy extruded at low temperature has high strength.

SIMULATION OF FINAL DIRECT EXTRUSION STAGE FOR LARGE RODS WITH LOW EXTRUSION RATIO

2018 ◽  
pp. 48-55
Author(s):  
V. R. Kargin ◽  
A. Yu. Deryabin
Keyword(s):  
Defect Formation ◽  
Cone Angle ◽  
Metal Flow ◽  
Joint Effect ◽  
Extrusion Ratio ◽  
Contact Friction ◽  
Extrusion Force ◽  
Direct Extrusion ◽  
Negative Effect ◽  
Edge Temperature

The direct extrusion of large 7075 alloy bars 188, 214, 252, 283, 326, 560 mm in diameter was simulated with 0 and 0,5 friction coefficients, 80° and 90° die cone angles from the 800 mm diameter container at the 200 MN press using the DEFORM-2D software package. It provided the distribution of metal flow radial velocities on the dummy block working surface versus the contact friction value, die cone angle and extrusion ratio factor at the main and final stages of extrusion. Butt-end height at the beginning of back-end extrusion defect formation was taken equal to a distance between the dummy block plane and the plane of extruded metal feeding into flat or cone die openings. The joint effect of the extrusion ratio factor, friction coefficient and die cone angle on the butt-end height, extrusion force, deformation and stress intensity factors, and die opening edge temperature was studied. Numerical experiments were performed based on the 23 complete factorial design for the following parameter variability intervals: Х1 = 3÷9, Х2 = 0÷0,5, Х3 = 80÷90°. Friction between the tool and the blank at the final extrusion stage has a negative effect due to a noticeable radial velocity reduction. This leads to the earlier initiation of central back-end extrusion defect formation. Extrusion into the conical die and increasing the extrusion ratio factor, on the contrary, speeds up radial flow velocity and ensures that the back-end extrusion defect starts forming later. The main factor that determines butt-end height is the extrusion ratio factor. A mathematical model is proposed to select the butt-end thickness for specific conditions of extruding large bars with low extrusion ratios.

Microstructures and Mechanical Properties of Y2O3 Ceramics

2017 ◽  
Vol 726 ◽  
pp. 179-183
Author(s):  
Tong Yu Zhu ◽  
Jin Feng Xia
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Sintering Temperature ◽  
High Density ◽  
Average Grain Size ◽  
Basic Performance ◽  
Different Temperatures ◽  
Microstructures And Mechanical Properties

Currently, Y2O3 ceramics are widely used in various fields. The basic performance of Y2O3 ceramics were sintered temperatures are studied in this paper, their phase compositions and microstructure are studied with XRD and SEM. The mechanical properties of Y2O3 ceramics at different temperatures are studied. The sintering temperature of Y2O3 ceramic significantly affected the final grain size and density. It was found that a high density and fine average grain size of Y2O3ceramic can be simultaneously achieved when the sintering temperature was 1600°C. To determine the best sintering temperature, grain size, density, and mechanical properties were considered, and the most suitable sintering temperature was found to be 1600°C.

EFFECT OF HOT EXTRUSION ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF ELECTROMAGNETIC CONTINUOUS CAST AZ31 MAGNESIUM ALLOY

2009 ◽  
Vol 23 (06n07) ◽  
pp. 990-995 ◽  
Author(s):  
GUOQING CHEN ◽  
JUNHUI SONG ◽  
XUESONG FU ◽  
YUXIAN ZHAO ◽  
WENLONG ZHOU
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Hot Extrusion ◽  
Az31 Alloy ◽  
Extrusion Ratio ◽  
Sectional Area ◽  
Continuous Cast ◽  
Cross Sectional

This paper describes the effect of hot extrusion on the microstructure and mechanical properties of electromagnetic continuous cast (EMC) AZ31 alloy. The microstructure, mechanical properties and fracture surfaces of AZ31 alloy before and after extrusion were investigated. The results demonstrate that extrusion processing gives rise to a strong basal texture. The grains are significantly refined and the average grain size of localized fine grain area is 2μm. Compared with EMC ingots, as-extruded specimens have much finer grain size and more uniform microstructure, and the second phase ( Mg 17 Al 12) becomes smaller and distributes more uniformly. The mechanical properties of the deformed AZ31 were improved after hot-extrusion. When the extrusion ratio was 10, the yield strength, ultimate tensile strength and reduction in cross-sectional area of as-extruded AZ31 alloy were 248MPa, 306MPa and 28.44%, which were respectively enhanced by 78.4%, 41% and 45.25%, compared with those of as-cast samples. With the increase of extrusion ratio, the grain refining effect was more significant and the microstructure was more uniform. The yield strength, ultimate tensile strength and reduction in cross-sectional area increased obviously with increasing the extrusion ratio. The observation on fracture surfaces demonstrates that the fracture mode changes from ductile-brittle fracture to ductile fracture after extrusion.

Effect of Extrusion Ratio on Microstructure and Mechanical Properties of As-Cast AZ91D Magnesium Alloy

2012 ◽  
Vol 445 ◽  
pp. 237-240
Author(s):  
Bao Hong Zhang ◽  
Zhi Min Zhang
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Magnesium Alloy ◽  
Yield Strength ◽  
Extrusion Ratio ◽  
Experimental Results ◽  
Direct Extrusion ◽  
Az91d Magnesium Alloy ◽  
Microstructure And Mechanical Properties

In order to study the effect of deformation extent on microstructure and mechanical properties of as-cast AZ91D magnesium alloy, experiments of direct extrusion were performed at temperature of 420 and different extrusion ratios. The microstructure and mechanical properties of billets and extrudates were measured. Experimental results show that the grain size of as-cast AZ91D magnesium alloy can be dramatically refined by extrusion. Direct extrusion can obviously improve the mechanical properties of as-cast AZ91D magnesium Alloy, comparing with the pre-extruded billet, the tensile strength, yield strength and elongation of extrudate can be improved by at least 83%, 154% and 150% respectively. As the extrusion ratio increases, the tensile strength and yield strength of extrudate will increase at first and then fall.

Influence of Extrusion Ratio on Microstructures and Properties of Cu-17Ni-3Al-X Alloy

2013 ◽  
Vol 477-478 ◽  
pp. 1307-1315 ◽  
Author(s):  
Yuan Hui Weng ◽  
Yuan Xuan Liu ◽  
Tan Wei ◽  
Wei Wen Zhang ◽  
Zong Qiang Luo
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Brinell Hardness ◽  
Cast Alloy ◽  
Optical Microscope ◽  
Extrusion Ratio ◽  
Hardness Testing ◽  
Second Phases ◽  
Microstructures And Mechanical Properties

The microstructures and mechanical properties of the Cu-17Ni-3Al-X alloy hot-extruded at different extrusion ratios were investigated by tensile and hardness testing, optical microscope (OM) and scanning electronic microscope.The results show that the dynamic re-crystallization occurs when the extrusion ratio λ increases from 8 to 25. The grain size and the second phases of the extruded alloys are obviously finer than that of the as-cast alloy. The mechanical properties of the extruded alloys are improved remarkably. The alloy with the λ of 25 obtained the tensile strength of 1025MPa, Brinell Hardness of 312HB and elongation of 10.0% which is 35%, 14% and 355%, respectively, higher than that of the as-cast alloy.

Microstructures and Mechanical Properties of Extruded High-Purity Magnesium

2015 ◽  
Vol 816 ◽  
pp. 439-445 ◽  
Author(s):  
Xiao Hui Feng ◽  
Hong Min Jia ◽  
Tian Jiao Luo ◽  
Yun Teng Liu ◽  
Ji Xue Zhou ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
High Purity ◽  
Basal Plane ◽  
Extrusion Speed ◽  
Direct Extrusion ◽  
Microstructure And Mechanical Properties ◽  
Microstructures And Mechanical Properties

The microstructure and mechanical properties of the high-purity magnesium (99.99wt.% Mg) extruded by single direct extrusion experiment were investigated. For the extrusion speed of 0.2mm/s, the microstructure of extruded Mg rods was composed of equiaxed fine dynamical recrystallized (DRXed) grains and some elongated coarse un-DRXed grains. The yield strength (YS) and the elongation of the extruded bars were 105.3MPa and 46.7% respectively. In the case of extrusion speed of 4.0mm/s, the DRXed grains were remarkably coarsened and the elongated coarse un-DRXed grains vanished, meanwhile lots of twins occurred and the intensity of basal-plane texture increased a little. With the extrusion speed being raised from 0.2mm/s to 4.0mm/s, the YS and the elongation decreased to 60.5MPa and 22.1% respectively, but the ultimate tensile strength (UTS) was improved from 154.7MPa to 178.8MPa.

Mechanical properties of FeAlSi powders prepared by mechanical alloying from different initial feedstock materials

2019 ◽  
Vol 107 (2) ◽  
pp. 207 ◽  
Author(s):  
Jaroslav Čech ◽  
Petr Haušild ◽  
Miroslav Karlík ◽  
Veronika Kadlecová ◽  
Jiří Čapek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Alloying ◽  
Young’S Modulus ◽  
Milling Time ◽  
Young's Modulus ◽  
Element Model ◽  
X Ray Diffraction ◽  
X Ray ◽  
Powder Particles ◽  
Complete Homogenization

FeAl20Si20 (wt.%) powders prepared by mechanical alloying from different initial feedstock materials (Fe, Al, Si, FeAl27) were investigated in this study. Scanning electron microscopy, X-ray diffraction and nanoindentation techniques were used to analyze microstructure, phase composition and mechanical properties (hardness and Young’s modulus). Finite element model was developed to account for the decrease in measured values of mechanical properties of powder particles with increasing penetration depth caused by surrounding soft resin used for embedding powder particles. Progressive homogenization of the powders’ microstructure and an increase of hardness and Young’s modulus with milling time were observed and the time for complete homogenization was estimated.

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