Strength and Formability of Fine-Grained Laminated Magnesium Alloy

2013 ◽  
Vol 753 ◽  
pp. 465-468
Author(s):  
Masafumi Noda ◽  
Kunio Funami

The development of laminated composite Mg alloy sheets, prepared by solid diffusion and roll bonding, is an effective way of improving the stiffness and surface properties of these materials while retaining their lightness. Laminated composites consisting of a core of Mg alloy between sheets of A5083 alloy as the coating material with Ti foil interlayers were prepared by solid diffusion and roll bonding. The laminated material had a strength and was resistant to cracking during deformation. Compounds that were formed and dispersed at the bonding interface between the Al and Mg alloys subjected to grain refinement improved the fracture toughness and strength of the composites, and it was important that these compounds were formed discontinuously. The fracture toughness of the laminated composite was twice that of the base Mg alloy, and its Young's modulus was 57 GPa.

2011 ◽  
Vol 411 ◽  
pp. 527-531
Author(s):  
Bing Zhang ◽  
Zhong Wei Chen ◽  
Shou Qian Yuan ◽  
Tian Li Zhao

In this paper, accumulative roll bonding (ARB) has been used to prepare the Al/Mg alloy multilayer structure composite materials with 1060Al sheet and MB2 sheet. The evolution of microstructure of the cladding materials during ARB processes was observed by optical microscope, scanning electron microscopy, and micro-hardness was measured by micro-hardness tester. The results show that a multilayer structure material of Al/Mg alloy with excellent bonding characteristics and fine grained microstructure was prepared by ARB processes. With the ARB cycles increasing, Mg alloy layer in multilayer composite material was necked and fractured, and the hardness of the Al and Mg alloy was increased. Average grain size was less than 1μm after ARB4 cycles.


2012 ◽  
Vol 05 ◽  
pp. 307-315 ◽  
Author(s):  
S.A. TORBATI-SARRAF ◽  
R. MAHMUDI

Different amounts of Al -5 Ti -1 B master alloy ( TiBAl ) were added to the AZ 31 magnesium alloy ( Mg -3 Al -1 Zn -0.2 Mn ) as grain refiner and the resulting microstructure and grain size distributions were studied after extrusion and equal channel angular pressing (ECAP). Results showed that the addition of 0.6% TiBAl had the strongest grain refinement effect, reducing the grain sizes by 54.5 and 48.5% in the extruded and ECAPed conditions, respectively. The observed grain refinement was partly due to the presence of the thermally-stable micron- and submicron-sized particles in the melt which act as nucleation sites during solidification. During the high-temperature extrusion and ECAP processes, dynamic recrystallization (DRX) and grain growth are likely to occur. However, the mentioned particles will help in reducing the grain size by the particle stimulated nucleation (PSN) mechanism. Furthermore, the pinning effect of these particles can oppose grain growth by reducing the grain boundary migration. These two phenomena together with the partitioning of the grains imposed by the severe plastic deformation in the ECAP process have all contributed to the achieved ultrafine-grained structure in the AZ 31 alloy.


2010 ◽  
Vol 654-656 ◽  
pp. 735-738 ◽  
Author(s):  
Tsuyoshi Furushima ◽  
Tetsuhide Shimizu ◽  
Kenichi Manabe

Grain refinement processing by severe deformation, combined equal-channel angular extrusion (ECAE) processing and conventional tube extrusion, is applied to AZ31 magnesium alloy. By a combination of ECAE processing and tube extrusion, a fabricated tube, with outer and inner diameters of 2 mm and 1 mm, respectively, has fine, homogeneous, and equiaxed grain structure with an average grain size of 1.5m. Tensile test results indicate that the fine-grained tubes exhibited a superplasticity potential m value of 0.55.The maximum elongation (688%) is obtained at a temperature of 673K. Furthermore, the tubes fabricated by combined ECAE/extrusion process is applied to dieless drawing process without using any tool and die.As a result, dieless drawing limit is enhanced due to high m value achieved by combined ECAE/Extrusion process. From these results, the effectiveness of new grain refinement processing for fabricating fine-grained tubes and its application for dieless drawing process to fabricate the fine tubes was demonstrated experimentally.


2007 ◽  
Vol 22 (9) ◽  
pp. 2598-2607 ◽  
Author(s):  
Hidetoshi Somekawa ◽  
Han S. Kim ◽  
Alok Singh ◽  
Toshiji Mukai

Fracture toughness and its deformed structures were investigated on a Mg–3Al–1Zn (AZ31) alloy processed by direct extrusion. The average grain sizes of the alloy after extrusion at temperatures of 473 and 573 K were 4.0 and 14.5 μm, respectively (i.e., fine-grained and coarse-grained alloys). The plane-strain fracture toughness, KIC, as determined by stretched zone analysis in fine-grained and coarse-grained alloys was estimated to be 24.9 and 22.7 MPam1/2, respectively. Microstructural observations of the fine-grained alloy after fracture toughness testing showed that non-basal slip and grain-boundary sliding was activated even at room temperature. In addition, the {10-12} deformation twins were observed despite the fine-grained structures. However, the fraction of deformation twins was reduced with grain refinement, which related to the enhancement of fracture toughness with grain refinement.


2006 ◽  
Vol 503-504 ◽  
pp. 155-160 ◽  
Author(s):  
Hidetoshi Somekawa ◽  
Toshiji Mukai

The fracture toughness was investigated using in an extruded AZ31 magnesium alloy with an initial grain size of 1.0 μm. Since the small scale yielding condition was not satisfied with the present thin thickness, the value of plane-strain fracture toughness, KIC = 27.9 MPam1/2, was measured from Stretched Zone analysis. The values of KIC in AZ31 magnesium alloys were dependent on the grain size. The grain refinement was found to be one of the improvement methods for fracture toughness in magnesium alloy.


2005 ◽  
Vol 475-479 ◽  
pp. 469-472 ◽  
Author(s):  
Ming Yi Zheng ◽  
Xiao Guang Qiao ◽  
Shi Wei Xu ◽  
Kun Wu ◽  
Shigeharu Kamado ◽  
...  

Equal channel angular extrusion (ECAE) was performed on as-cast ZW1101 (Mg-11wt%Zn- 0.9wt%Y) Mg alloy containing quasicrystallines. The grain size of α-Mg was effectively refined, and coarse eutectic quasicrystalline phases were broken and dispersed in the alloy by ECAE. The alloy processed by ECAE exhibited a good combination of high strength and high ductility, which is due to the grain refinement and fine dispersed quasicrystallines in the alloy.


1999 ◽  
Vol 40 (8) ◽  
pp. 765-771 ◽  
Author(s):  
Nobuhiro Tsuji ◽  
Katsuhiko Shiotsuki ◽  
Yoshihiro Saito

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