Structure and mechanical properties of cast quasicrystal-reinforced Mg–Zn–Al–Y base alloys

2004 ◽  
Vol 19 (5) ◽  
pp. 1531-1538 ◽  
Author(s):  
Guangyin Yuan ◽  
Kenji Amiya ◽  
Hidemi Kato ◽  
Akihisa Inoue
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperatures ◽  
Cast Alloy ◽  
Strengthening Mechanism ◽  
Icosahedral Quasicrystal ◽  
Compression Tests ◽  
Strengthening Phase ◽  
Creep Tests ◽  
Cast Alloys ◽  
Bulk Alloys

The structure and mechanical properties of Mg–Zn–Al–Y base cast alloys containing an icosahedral quasicrystal phase (i-phase) as a main strengthening phase were investigated. Mg–8Zn–4Al–xY base bulk alloys containing the i-phase were prepared by casting into a copper mold at moderate cooling rates. The Y addition was effective for decreasing the size of the i-phase and the increasing the homogeneity of its dispersed state. The mechanical properties examined by compression tests at room temperature were much superior to those of a conventional AZ91 Mg alloy. The creep tests at elevated temperatures indicated a promising high temperature creep resistance of the quasicrystal-reinforced Mg–Zn–Al–Y cast alloy. The strengthening mechanism was also discussed.

High Mechanical Properties of Cast Quasicrystal-Reinforced Mg-Alloys

2005 ◽  
Vol 488-489 ◽  
pp. 127-130
Author(s):  
Guang Yin Yuan ◽  
Wen Jiang Ding ◽  
Kenji Amiya ◽  
Hidemi Kato ◽  
Akihisa Inoue
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Cast Alloy ◽  
Strengthening Mechanism ◽  
Az91 Alloy ◽  
Icosahedral Quasicrystal ◽  
High Temperature Creep ◽  
Strengthening Phase ◽  
Creep Tests ◽  
Copper Mould

Mg-8Zn-4Al-xY base alloys containing an icosahedral quasicrystal phase (i-phase) as a main strengthening phase were prepared by casting into a copper mould at moderate cooling rates. The Y addition was effective for decreasing the size of i-phase and the more homogeneousness of its dispersed state. The mechanical properties at room temperature were much superior to those of AZ91 alloy. The creep tests indicated a promising high temperature creep resistance of the quasicrystal-reinforced Mg-Zn-Al-Y cast alloy. The dislocation characteristic in crept specimens which containing i-phase and no i-phase was analyzed and strengthening mechanism was discussed.

Effect of Warm Deforming and Heat Treating on Microstructure and Mechanical Properties of Mg-Zn-Zr Magnesium Alloy

2012 ◽  
Vol 472-475 ◽  
pp. 707-711
Author(s):  
Guan Lu ◽  
Ya Qin Yang ◽  
Bao Cheng Li ◽  
Zhi Min Zhang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Cast Alloy ◽  
Hot Extrusion ◽  
Heat Treating ◽  
Optical Microscope ◽  
Tensile Fracture ◽  
Strengthening Effect ◽  
Zk60 Alloy ◽  
Cast Alloys

In this paper, the effects of hot extrusion and T5、T6 heat treatment on the microstructures and mechanical properties of ZK60 magnesium alloys are investigated by optical microscope, electronic scanning microscope and mechanical testers. The result shows that both the tensile strength and the elongation of the ZK60 alloy extruded at 380°Care much higher than that of the as-cast alloys, as there are much granular second phases precipitated during the extrusion. The tensile strength of the extruded and T5 treated alloy increases while the elongation decreases faster than that of the extruded alloy. The strengthening effect of the T6 treatment is inferior to that of the T5 treatment. The tensile fracture of the as-cast alloy is brittle fractured while that of the extruded and T5 treated alloy is ductile fractured with lots of deep and even dimples.

Effect of Test Temperature on Mechanical Properties of Austenitic 0.12C18Cr10NiTi and 0.08C16Cr11Ni3Mo Steels Irradiated by Fast Neutrons in the BN-350 Reactor

2017 ◽  
Vol 375 ◽  
pp. 134-138 ◽  
Author(s):  
Alexey Dikov ◽  
Sergey Kislitsin ◽  
Ivan Chernov
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperatures ◽  
Spent Nuclear Fuel ◽  
Relative Elongation ◽  
Austenitic Steels ◽  
Fast Neutrons ◽  
Creep Tests ◽  
Microstructural Investigation ◽  
Α Phase ◽  
And Storage

12C18Cr10NiТi and 0.08C16Cr11Ni3Мo austenitic steels serve as structural materials for fuel assembly covers in the BN-350 fast reactor, as well as for the covers of transport packagings for transportation and storage of spent nuclear fuel (SNF). To predict failure of these elements, it is of paramount importance to know their mechanical properties at elevated temperatures after in-pile irradiation. We performed tensile and creep tests at room temperature (RT), 350 °C and 450 °C of irradiated samples cut from the higher half of fuel duct pipes of the BN-350 reactor. A non-monotonic temperature dependence of tensile strength, yield stress, and relative elongation was shown. Microstructural investigation revealed the origin of this dependence lies in the different distribution of carbides and is also associated with the formation of α'-phase.

Fabrication of Aluminum/Aluminum Nitride Composites by Reactive Mechanical Alloying

2007 ◽  
Vol 534-536 ◽  
pp. 181-184
Author(s):  
Seung Hoon Yu ◽  
Kwang Seon Shin
Keyword(s):  
Mechanical Properties ◽  
Mechanical Alloying ◽  
Elevated Temperatures ◽  
Hot Extrusion ◽  
Extrusion Process ◽  
Processing Technique ◽  
Compression Tests ◽  
Composite Powders ◽  
Al Matrix Composites

Various reactions and the in-situ formation of new phases can occur during the mechanical alloying process. In the present study, Al powders were strengthened by AlN, using the in-situ processing technique during mechanical alloying. Differential thermal analysis and X-ray diffraction studies were carried out in order to examine the formation behavior of AlN. It was found that the precursors of AlN were formed in the Al powders and transformed to AlN at temperatures above 600oC. The hot extrusion process was utilized to consolidate the composite powders. The composite powders were canned in an Al can and then extruded at elevated temperatures. The microstructure of the extrusions was examined by SEM and TEM. In order to investigate the mechanical properties of the extrusions, compression tests and hardness measurements were carried out. It was found that the mechanical properties and the thermal stability of the Al/AlN composites were significantly greater than those of conventional Al matrix composites.

scholarly journals Study of the precipitation hardening process in recycled Al-Si-Cu cast alloys

2017 ◽  
Vol 62 (1) ◽  
pp. 397-403 ◽  
Author(s):  
L. Kuchariková ◽  
E. Tillová ◽  
M. Matvija ◽  
J. Belan ◽  
M. Chalupová
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Precipitation Hardening ◽  
Cast Alloy ◽  
Solution Treatment ◽  
Second Phase ◽  
Thin Foils ◽  
Transmission Electron ◽  
Different Temperatures ◽  
Cast Alloys

AbstractThe formation of extremely small uniformly dispersed particles of a second phase within the original phase matrix during heat treatment changed material properties. Therefore the characterization of precipitation had been investigated using high resolution transmission electron microscopy (TEM) and electron diffraction of thin foils for an AlSi9Cu3 cast alloy. For investigation the hardening effect onto mechanical properties of aluminium cast was used heat treatment, which consisted from solution treatment at 515°C / 4 hours (h), followed by quenching into water with temperature 50°C and artificial aging using different temperatures 170°C and 190°C with different holding time 2, 4, 8, 16, and 32 hours. The observations of microstructure and substructure reveals that precipitation hardening has caused great changes in size, morphology and distributions of structural components, the formation of precipitates of Cu phases, and the change of mechanical properties as well.

Mechanical Behavior and Microstructure Evolution of Mg-Gd-Y-Zn-Zr Alloy during Multipass Hot Compression Deformation

2016 ◽  
Vol 849 ◽  
pp. 186-195 ◽  
Author(s):  
Jian Min Yu ◽  
Xu Bin Li ◽  
Zhi Min Zhang ◽  
Qiang Wang ◽  
Yao Jin Wu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Microstructure Evolution ◽  
Cast Alloy ◽  
Hardness Test ◽  
Hot Compression ◽  
Compression Tests ◽  
Softening Effect ◽  
Hot Compression Deformation ◽  
Compression Deformation ◽  
Multipass Deformation

The multi-pass hot compression deformation behavior of the cast alloy with the composition of Mg-13Gd-4Y-2Zn-0.6Zr, was investigated, and the four-pass compression tests were conducted at the temperatures ranging from 350°C to 500°C and strain rate 0.01 s-1. The experimental results showed that the alloys incurred different degrees of softening by multipass deformation. The microstructure evolution for the deformed alloy was investigated, the influence of the microstructure on the hardness properties of the alloy discussed. The tests reveal that dynamic recrystallization is not the main softening mechanism for this alloy; rather, kink deformation refines the grains to achieve the observed softening effect. The hardness test curve showed that the hardness increased gradually with an increasing number of deformation passes. The improvement of the main mechanical properties related to the strengthening by the grain refinement. In multipass deformation, the misorientation of the kink belt gradually increased,and refined the grains. On the other hand, the grain size of the eutectic phase at the grain boundary decreased with increase of deformation passes. In addition, the mechanical properties were improved by the distribution dispersion of tiny cuboidal particles and acicular-like phases in the matrix.

Microstructure and Tensile Creep Behavior of Mg-Nd-RE-Ca Casting Alloys

2007 ◽  
Vol 345-346 ◽  
pp. 557-560 ◽  
Author(s):  
Joong Hwan Jun ◽  
Bong Koo Park ◽  
Jeong Min Kim ◽  
Ki Tae Kim ◽  
Woon Jae Jung
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperatures ◽  
Tensile Creep ◽  
Secondary Creep ◽  
Creep Tests ◽  
X Ray ◽  
Casting Alloys ◽  
High Temperature Mechanical Properties ◽  
Ca Addition ◽  
Average Size

Influences of Ca addition on microstructures and mechanical properties at room and elevated temperatures have been investigated for Mg-1.5%Nd-1.0%RE-0.5%Zn-(0~1.0)%Ca casting alloys, on basis of experimental results from X-ray diffractometry (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS), tensile and creep tests. Microstructures of the alloys are characterized by dendritic α-(Mg) grains surrounded by Mg12Nd-Zn-(Ca) eutectic network phase. The average size of α grains decreases gradually with an increase in Ca content. At room temperature, yield strength (YS) is enhanced with increasing Ca content with a decrease in ultimate tensile strength (UTS) and elongation to fracture, whereas the Ca addition leads to greater YS and UTS at 175oC. The tensile creep strain and secondary creep rate, measured at 150 and 200oC under 100MPa for 100hrs, become lower with the increase in Ca content. The obtained tensile properties at elevated temperature demonstrate that the addition of Ca plays a role in improving high temperature mechanical properties including creep resistance for the Mg-Nd-RE-Zn-(Ca) alloys. In view of microstructural evolution, this would be attributed to the refined primary α grains and higher thermal stability of the Mg12Nd-Zn-Ca eutectic strengthening phase.

Effects of Alloying Elements on Mechanical Properties of Mg-Al Alloys

2005 ◽  
Vol 488-489 ◽  
pp. 845-848 ◽  
Author(s):  
Yeon Jun Chung ◽  
Jung Lae Park ◽  
Nack J. Kim ◽  
Kwang Seon Shin
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Elevated Temperatures ◽  
Casting Machine ◽  
Al Alloys ◽  
Alloying Elements ◽  
Tensile Creep ◽  
Thermally Stable ◽  
Creep Tests ◽  
High Temperature Mechanical Properties

The effects of alloying elements on the microstructure and high temperature mechanical properties of Mg-Al alloys were investigated in this study. In order to improve the high temperature mechanical properties, Sr or Mm was added to the Mg-9Al alloy. The effect of Sn on the Mg-9Al alloy was also examined since Sn was expected to improve the high temperature mechanical properties by forming the thermally stable Mg2Sn phase. The specimens used in this study were produced on a 320 ton cold chamber high-pressure die casting machine. The microstructures of the specimens were examined by optical and scanning electron microscopy and tensile and creep tests were performed at elevated temperatures. Tensile tests were carried out at room temperature, 150oC and 200oC using an initial strain rate of 2×10-4/sec. In addition, tensile creep tests were conducted at the stress levels of 50 MPa and 70 MPa. From the microstructure analyses of the specimens after heat treatment at 400oC for 12 hours, it was found that most of the Mg17Al12 precipitate dissolved into the matrix, while the thermally stable phases continued to exist. The high temperature mechanical properties of the Mg-9Al alloys were found to improve significantly with the additions of Sr, Mm and Sn, due to the formation of the thermally stable precipitates.

Thermal and Loading Effects on Mechanical Properties of a Hot Isostatically Pressed Si3N4

1994 ◽  
Author(s):  
Jagannathan Sankar ◽  
Jayant Neogi ◽  
Suneeta S. Neogi ◽  
Marvln T. Dixie ◽  
Ranji Vaidyanathan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Silicon Nitride ◽  
Elevated Temperatures ◽  
Heat Engine ◽  
Tensile Tests ◽  
Tensile Creep ◽  
Uniaxial Tensile ◽  
Creep Tests ◽  
Loading Effects

The effect of thermal soaking on the mechanical properties of a candidate material for advanced heat engine applications namely, hot isostatically pressed (HIPed) silicon nitride (GTEPY6) are reported here. Pure uniaxial tensile tests conducted at room and at elevated temperatures indicated that the tensile strength of this material dropped significantly after 1000°C. The residual tensile strength of PY6 material after thermal soaking at 1200° and 1300°C was also investigated. Test results showed that thermal soaking at 1200° and 1300°C increased the residual tensile strength. The thermal soaking time had a greater effect on the residual tensile strength at 1300°C. Tensile creep tests performed at 1200° and 1300°C showed that the steady state creep rate was influenced by both the temperature and the applied stress. The higher stress exponent in HIPed as compared to a sintered silicon nitride shows higher creep resistance in the case of HIPed materials.

scholarly journals An Effect of Chromium on Mechanical Properties of the Ni3Al-Based Alloys and Sinters in Compression Tests

2011 ◽  
Vol 56 (4) ◽  
pp. 1007-1014 ◽  
Author(s):  
W. Malec ◽  
K. Rzyman ◽  
M. Czepelak ◽  
A. Wala
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Point Of View ◽  
Compression Tests ◽  
Wide Range ◽  
Cast Alloys ◽  
Intended Use ◽  
Temperature Applications

An Effect of Chromium on Mechanical Properties of the Ni3Al-Based Alloys and Sinters in Compression TestsMechanical properties of the Ni75Al(25-x)Crx cast alloys and sinters were investigated using compression tests conducted within a wide range of compositions and temperature. The alloys and sinters exhibiting the best mechanical properties from a point of view of their intended use as constructional materials suitable for high-temperature applications were selected.

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