Microstructure and Formability of Different-Speeds Rolled AZ31 Mg Sheet

2007 ◽  
Vol 544-545 ◽  
pp. 407-410 ◽  
Author(s):  
Jae Seol Lee ◽  
Hyeon Taek Son ◽  
Young Kyun Kim ◽  
Ik Hyun Oh ◽  
Chang Seog Kang ◽  
...  

The aims of this study ares to investigate the microstructure evolution of AZ31 Mg alloys with normal rolling and different speeds rolling during hot rolling affects microstructure, texture and mechanical properties of AZ31 Mg alloy. In the microstructures of as-rolled both samples, twins are clearly apparent, small and recrystallized grains are visible along some grain boundary and twinned regions. The tensile strength and yield strength of DSR sample were slightly higher than that of NR sample. Also, in the case of the NR sample, tensile strength indicated different values to the rolling directions. From this result, NR sample compared to DSR sample strongly indicated to the plastic anisotropy tendency. Therefore, it is noted that DSR sample could be presented to the good formability, comparing to the NR sample. DSR samples deformed at 473K and 523K could be perfectly formed, indicating the potential application of the DSR process to improve formability of the Mg alloys at warm temperatures.

Author(s):  
Honggang Zhang ◽  
Jinhui Wang ◽  
Hongbin Ma ◽  
Yuan Yuan ◽  
Yongfeng Li ◽  
...  

Abstract The improvement of mechanical properties and the microstructure evolution through adding Sc to AZ61magnesium alloy were studied. The results indicated that the Mg17Al12 phase in the extruded AZ61 alloy was mainly distributed around the sub-structured and fine deformed grains, resulting in the nonuniform microstructure. The addition of Sc could effectively suppress the band-like precipitation of Mg17Al12 phase and improve the uniformity of microstructure. The grain sizes of the extruded alloys showed a trend of first decreasing and then increasing with the increase of Sc, which was mainly attributed to the secondary phase. The AZ61-0.5Sc alloy exhibited the best mechanical properties, its ultimate tensile strength and yield strength were 14.8MPa and 40.8MPa higher than those of the extruded AZ61 alloy, respectively, which was ascribed to the fine grains and abundant secondary phase in the alloy.


Crystals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 644
Author(s):  
Wenyan Zhang ◽  
Hua Zhang ◽  
Lifei Wang ◽  
Jianfeng Fan ◽  
Xia Li ◽  
...  

AZ31 magnesium alloy sheets were prepared by low-speed extrusion at different temperatures, i.e., 350 °C, 400 °C, and 450 °C. The microstructure evolution and mechanical properties of extruded AZ31 magnesium alloy sheets were studied. Results indicate that the low-speed extrusion obviously improved the microstructure of magnesium alloys. As the extrusion temperature decreased, the grain size for the produced AZ31 magnesium alloy sheets decreased, and the (0001) basal texture intensity of the extruded sheets increased. The yield strength and tensile strength of the extruded sheets greatly increased as the extrusion temperature decreased. The AZ31 magnesium alloy sheet prepared by low-speed extrusion at 350 °C exhibited the finest grain size and the best mechanical properties. The average grain size, yield strength, tensile strength, and elongation of the extruded sheet prepared by low-speed extrusion at 350 °C were ~2.7 μm, ~226 MPa, ~353 MPa, and ~16.7%, respectively. These properties indicate the excellent mechanical properties of the extruded sheets prepared by low-speed extrusion. The grain refinement effect and mechanical properties of the extruded sheets produced in this work were obviously superior to those of magnesium alloys prepared using traditional extrusion or rolling methods reported in other related studies.


2017 ◽  
Vol 727 ◽  
pp. 124-131
Author(s):  
Cai Chen ◽  
Rui Wang ◽  
Xing Hao Du ◽  
Bao Lin Wu

In this work, the tensile properties of AZ31 Mg alloy deformed by multi-directional forging (MDF) were investigated at room temperature. And the enhanced mechanical properties of yield strength of 93 MPa, ultimate tensile strength (UTS) of 253 MPa and elongation of 29% were achieved. It is discovered that the MDF deformation makes the crystallographic orientation of original as-cast microstructure randomization, providing the condition for the following twinning during tensile deformation. In addition, the original fine grains and continuously refined grains can enhance the strength by restricting the growth of grains and motion of dislocations.


Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 853
Author(s):  
Lin Wang ◽  
Charlie Kong ◽  
Puneet Tandon ◽  
Alexander Pesin ◽  
Denis Pustovoytov ◽  
...  

The mechanical properties and microstructure evolution of an Al-Cu-Li alloy sheet processed via hot rolling (HR) (at 400 °C and 500 °C) or cryorolling (CR) (at −100 °C and −190 °C) and subsequence aging at 160 °C for 10 h were investigated. Before aging, the highest ultimate tensile strength of 502 MPa was achieved when the sheets were cryorolled at −190 °C, while the better ultimate tensile strength of 476 MPa and the best elongation rate of 11.1% was achieved simultaneously when the sheets were cryorolled at −100 °C. The refined grains and numerous uniform deformation-induced dislocations microstructures were responsible for the improved strength and enhanced ductility of the cryorolled sheets compared to that of the alloy processed by hot rolling with a low dislocation density zone (LDDZ) and high dislocation density zone (HDDZ). After aging at 160 °C for 10 h, the ultimate tensile strength further improved resulted from the greater precipitation strengthening, and the increased precipitates provided greater resistance to dislocations movement resulting in the increased ductility although the dislocation density decreased. The uniform dislocation microstructures in the cryorolled sheets provide numerous nucleation sites for the precipitates, leading to higher strength after aging.


2011 ◽  
Vol 675-677 ◽  
pp. 629-632
Author(s):  
Ai Hui Liu ◽  
Yan Wei Sui ◽  
Bang Sheng Li ◽  
Jing Jie Guo

In this work, the effects of centrifugal radius and mould rotation speed on the tensile strength, yield strength, specific elongation, and microhardness on Al-Cu alloy castings are investigated. The results show that, with increasing the centrifugal radius or mould rotation speed, the mechanical properties increase gradually. With increasing the centrifugal radius, the variation amplitude of mechanical properties of Al-Cu alloys at mould rotation speed 600rpm is greater than that at 300rpm. This is due to the finer microstructure and the strengthened grain boundary and then resulting in the increase of the resistance to dislocation slipping.


2013 ◽  
Vol 873 ◽  
pp. 10-18
Author(s):  
Ting Ting Jia ◽  
Guo Shi Chen ◽  
Shuo Zhang ◽  
Ming Wu ◽  
Hao Ran Geng

In this study, hypoeutectic Al-Si casting alloy was investigated to obtain high strength, according to alloying of Cu Mg, refining of Al-5Ti-B master alloy, modifing of Re and T6 heat treatment. The experimental results show that the mechanical properties of the tested alloy reach peak when addition of Al-5Ti-1B alloy is 1.0% after heat treatment, especially the yield strength, correspondingly, microstructure distribution gets to the best state. When Al-5Ti-1B exceeds 1.0%, the mechanical properties descend gradually. The metallic compounds of Mg2Si phase, CuA12 phase and W phase precipitated along the grain boundary and strengthened dispersively can improve mechanical properties of the tested alloys. The yield strength of samples added 0.1% Re (La 50%, Ce 40%) increases slightly, simultaneously, the tensile strength and elongation decreases. After 0.1% Re, the mechanical properties get down.


2013 ◽  
Vol 747-748 ◽  
pp. 489-496 ◽  
Author(s):  
Chong Lin Jia ◽  
Qiang Fan ◽  
Ying Wang ◽  
Yong Yue Zhang ◽  
Qun Li

With cold rolling deformation between 12.5% and 60% for GH 536 superalloy strips, effect of deformation on the mechanical properties, texture formation and microstructure evolution have been investigated. The results show that an increase of deformation will lead to an increase of mechanical properties. As the deformation was 60%, the tensile strength and yield strength of the strip were 1430MPa and 1370MPa, respectively, and the elongation of strip was 4.5%. Also, an increase of deformation will lead to an increase of hardness, yield ratio and deformation resistance as well as an increase of rolling textures such as Goss {110}<001>, S{213}<4>, Copper {112}<1> and especially Brass {110}<12>. The optimized processing parameters of cold rolling deformation between 25% and 37.5% have been proposed to obtain an excellent formability and cold workability for GH 536 superalloy strips.


2012 ◽  
Vol 268-270 ◽  
pp. 291-296
Author(s):  
Li Min Wang ◽  
Zhi Hua Gong ◽  
Gang Yang ◽  
Zheng Dong Liu ◽  
Han Sheng Bao

Ultrafine-grain or even nano-grain microstructure can be made by equal channel angular pressing (ECAP), mainly resulting from shear strain. The authors experimentally investigated 00Cr18Ni12 austenitic stainless steel and its mechanical properties during and after ECAP. The results showed that because of larger shear stress, many slipping bands occured inside grains, with the increase of pressing pass, the slipping bands may interact with each other to separate slipping bands into sub-grains, finally, the sub-grains transformed into new grains with large angular boundaries. The grain size was about 200nm after the 7th pass. After the 1st and 2nd pass, the tensile strength was higher 93% and 144% than that without ECAP, the yield strength was 5.3 and 6.6 times of that without ECAP respectively.


Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 404
Author(s):  
Nur Sharmila Sharip ◽  
Hidayah Ariffin ◽  
Tengku Arisyah Tengku Yasim-Anuar ◽  
Yoshito Andou ◽  
Yuki Shirosaki ◽  
...  

The major hurdle in melt-processing of ultra-high molecular weight polyethylene (UHMWPE) nanocomposite lies on the high melt viscosity of the UHMWPE, which may contribute to poor dispersion and distribution of the nanofiller. In this study, UHMWPE/cellulose nanofiber (UHMWPE/CNF) bionanocomposites were prepared by two different blending methods: (i) melt blending at 150 °C in a triple screw kneading extruder, and (ii) non-melt blending by ethanol mixing at room temperature. Results showed that melt-processing of UHMWPE without CNF (MB-UHMWPE/0) exhibited an increment in yield strength and Young’s modulus by 15% and 25%, respectively, compared to the Neat-UHMWPE. Tensile strength was however reduced by almost half. Ethanol mixed sample without CNF (EM-UHMWPE/0) on the other hand showed slight decrement in all mechanical properties tested. At 0.5% CNF inclusion, the mechanical properties of melt-blended bionanocomposites (MB-UHMWPE/0.5) were improved as compared to Neat-UHMWPE. It was also found that the yield strength, elongation at break, Young’s modulus, toughness and crystallinity of MB-UHMWPE/0.5 were higher by 28%, 61%, 47%, 45% and 11%, respectively, as compared to the ethanol mixing sample (EM-UHMWPE/0.5). Despite the reduction in tensile strength of MB-UHMWPE/0.5, the value i.e., 28.4 ± 1.0 MPa surpassed the minimum requirement of standard specification for fabricated UHMWPE in surgical implant application. Overall, melt-blending processing is more suitable for the preparation of UHMWPE/CNF bionanocomposites as exhibited by their characteristics presented herein. A better mechanical interlocking between UHMWPE and CNF at high temperature mixing with kneading was evident through FE-SEM observation, explains the higher mechanical properties of MB-UHMWPE/0.5 as compared to EM-UHMWPE/0.5.


Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 31
Author(s):  
Hongxin Liao ◽  
Taekyung Lee ◽  
Jiangfeng Song ◽  
Jonghyun Kim ◽  
Fusheng Pan

The microstructures and mechanical properties of the Mg88.5Zn5Y6.5-XREX (RE = Yb and Ce, X = 0, 1.5, 3.0, and 4.5) (wt.%) alloys were investigated in the present study. Mg88.5Zn5Y6.5 is composed of three phases, namely, α-Mg, long-period stacking ordered (LPSO) phases, and intermetallic compounds. The content of the LPSO phases decreased with the addition of Ce and Yb, and no LPSO phases were detected in Mg88.5Zn5Y2.0Yb4.5. The alloys containing the LPSO phases possessed a stratified microstructure and exhibited excellent mechanical properties. Mg88.5Zn5Y5.0Ce1.5 exhibited the highest creep resistance and mechanical strength at both room temperature and 200 °C, owing to its suitable microstructure and high thermal stability. The yield strength of Mg88.5Zn5Y5.0Ce1.5 at room temperature was 358 MPa. The ultimate tensile strength of Mg88.5Zn5Y5.0Ce1.5 at room temperature and 200 °C was 453 MPa and 360 MPa, respectively.


Sign in / Sign up

Export Citation Format

Share Document