Effect of Cr content on microstructure and mechanical properties of annealed large-dimensional bulk nanocrystalline Fe–Al–Cr alloys by self-propagating combustion synthesis

2019 ◽  
Vol 9 (6) ◽  
pp. 641-647
Author(s):  
Hongding Wang ◽  
Qiangqiang Wang ◽  
Hong Liu ◽  
Peiqing La ◽  
Zhengning Li
Keyword(s):  
Mechanical Properties ◽  
Combustion Synthesis ◽  
Deformation Behavior ◽  
Isothermal Treatment ◽  
Second Phase ◽  
Cr Content ◽  
Microstructure Transformation ◽  
Average Grain Size ◽  
Bulk Nanocrystalline ◽  
20 Nm

Large-dimensional bulk nanocrystalline Fe–Al–Cr alloys with different chromium contents (5, 10, 15 and 20 wt.%) were prepared by self-propagating combustion synthesis. After isothermal treatment at 1000 °C for 16 hours, the microstructure transformation and the deformation behavior of Fe–Al–Cr alloys were studied and discussed. After annealing, the nanocrystalline matrix of the alloys changed slightly, and the average grain size remained as approximately 20 nm. Owing to the changes in the distribution and shape of the second phase, the annealed nanocrystalline Fe–Al–Cr alloys with different chromium contents provided good plasticity and strength. The annealed Fe–Al–Cr alloy with 15 wt.% chromium achieved the best comprehensive mechanical properties.

scholarly journals Formation and Properties of the Ta-Y2O3, Ta-ZrO2, and Ta-TaC Nanocomposites

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
J. Jakubowicz ◽  
M. Sopata ◽  
G. Adamek ◽  
P. Siwak ◽  
T. Kachlicki
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Mechanical Alloying ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Ceramic Composites ◽  
Ceramic Phase ◽  
Plasma Sintering ◽  
Average Grain Size ◽  
Bulk Nanocrystalline

The nanocrystalline tantalum-ceramic composites were made using mechanical alloying followed by pulse plasma sintering (PPS). The tantalum acts as a matrix, to which the ceramic reinforced phase in the concentration of 5, 10, 20, and 40 wt.% was introduced. Oxides (Y2O3 and ZrO2) and carbides (TaC) were used as the ceramic phase. The mechanical alloying results in the formation of nanocrystalline grains. The subsequent hot pressing in the mode of PPS results in the consolidation of powders and formation of bulk nanocomposites. All the bulk composites have the average grain size from 40 nm to 100 nm, whereas, for comparison, the bulk nanocrystalline pure tantalum has the average grain size of approximately 170 nm. The ceramic phase refines the grain size in the Ta nanocomposites. The mechanical properties were studied using the nanoindentation tests. The nanocomposites exhibit uniform load-displacement curves indicating good integrity and homogeneity of the samples. Out of the investigated components, the Ta-10 wt.% TaC one has the highest hardness and a very high Young’s modulus (1398 HV and 336 GPa, resp.). For the Ta-oxide composites, Ta-20 wt.% Y2O3 has the highest mechanical properties (1165 HV hardness and 231 GPa Young’s modulus).

Variation of Microstructure and Mechanical Properties of ZW61 Magnesium Alloy Solidified under Different Pressures

2022 ◽  
Vol 327 ◽  
pp. 3-10
Author(s):  
Shu Sen Wu ◽  
Xiao Gang Fang ◽  
Shu Lin Lü ◽  
Long Fei Liu ◽  
Wei Guo
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Volume Fraction ◽  
Applied Pressure ◽  
Second Phase ◽  
Cast State ◽  
Microstructure And Properties ◽  
Microstructure Refinement ◽  
Porosity Reduction ◽  
Average Grain Size

There is little datum related to microstructure and properties of Mg alloys squeeze-casted with pressure over 200 MPa. In this study, the microstructure and properties of Mg-6Zn-1.4Y (ZW61) alloy solidified under 100MPa to 800MPa were investigated. The results show that a remarkable microstructure refinement and porosity reduction can be reached through solidification under high pressure. The average grain size and the volume fraction of second phase, i.e. quasicrystal I-phase, decrease continuously with the increase of applied pressure. The tensile properties, especially elongation, are obvious enhanced because of the microstructure refinement and castings densification under high pressure. The ultimate tensile strength and elongation of ZW61 alloy in as-cast state are 243 MPa and 18.7% when the applied pressure is 800 MPa, which are increased by 35% and 118% respectively, compared with that of the gravity castings.

Simultaneous Synthesis and Consolidation of Nanostructured ZrB2–ZrO2 Composite

2020 ◽  
Vol 20 (7) ◽  
pp. 4349-4352
Author(s):  
Seong-Eun Kim ◽  
Jin-Kook Yoon ◽  
In-Jin Shon
Keyword(s):  
Mechanical Properties ◽  
Combustion Synthesis ◽  
High Frequency ◽  
Combined Effects ◽  
Induced Current ◽  
Mechanical Pressure ◽  
Simultaneous Application ◽  
Average Grain Size ◽  
One Step ◽  
Simultaneous Synthesis

A dense nanostructured 2ZrB2–ZrO2 composite was synthesized by the high-frequency inductionheated combustion synthesis (HFIHCS) method within 2 min in one step from mechanically activated powders of 2B2O3 and 3Zr. Simultaneous combustion synthesis and densification were accomplished under the combined effects of the induced current and mechanical pressure. A highly dense 2ZrB2–ZrO2 composite with relative density of up to 95.5% was produced under the simultaneous application of a pressure of 80 MPa and the induced current. The average grain size and mechanical properties (hardness and fracture toughness) of the composite were investigated.

Mechanical Properties of Bulk Nanocrystalline Silver-Using Compression Tests

2010 ◽  
Vol 152-153 ◽  
pp. 1313-1316
Author(s):  
Guo Jun Hu ◽  
Zhi Quan Hong
Keyword(s):  
Mechanical Properties ◽  
Coarse Grained ◽  
Strain Rates ◽  
Test Results ◽  
Compression Tests ◽  
Static Test ◽  
Rate Dependent ◽  
Average Grain Size ◽  
Bulk Nanocrystalline ◽  
The Relationship

In this paper, the compression test on the bulk nanocrystalline sliver ( n Ag) with average grain size of 50 nm was made. The stress-strain curves under different strain rates were obtained by test. The test results show that the mechanical behavior of n Ag is rate-dependent, and the dynamic compress yield stress are about 1.5 times of that n Ag in static test condition; The effect of strain harding on n Ag is smaller than that of coarse-grained silver (c Ag) in plastic deformation; The relationship between the yield strength and the logarithm of strain rate is approximately linear.

One Step Synthesis and Consolidation of Nanostructured ZrSi2-SiC Composite and its Mechanical Properties

2007 ◽  
Vol 124-126 ◽  
pp. 1149-1152
Author(s):  
In Jin Shon ◽  
Hyun Kuk Park ◽  
In Yong Ko ◽  
Jin Kook Yoon ◽  
Kyung Tae Hong
Keyword(s):  
Mechanical Properties ◽  
Combustion Synthesis ◽  
High Frequency ◽  
Combined Effects ◽  
Induced Current ◽  
Mechanical Pressure ◽  
Simultaneous Application ◽  
Average Grain Size ◽  
One Step ◽  
High Frequency Induction

Dense nanostructured ZrSi2-SiC composite was synthesized by high frequency induction heated combustion synthesis (HFIHCS) method within 1 minute in one step from powders of ZrC and 3Si. Simultaneous combustion synthesis and densification were accomplished under the combined effects of an induced current and mechanical pressure. Highly dense ZrSi2-SiC with relative density of up to 98% were produced under simultaneous application of a 60MPa pressure and the induced current. The average grain size and mechanical properties (hardness and fracture toughness) of the composite were investigated.

Mechanical Properties of ECAE Nanocrystalline Copper and Nickel

2005 ◽  
Vol 23 ◽  
pp. 183-186 ◽  
Author(s):  
S. Bansal ◽  
A.M. Saxena ◽  
T. Hartwig ◽  
Rao R. Tummala
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Grain Size ◽  
Tensile Strength ◽  
High Purity ◽  
Bulk Sample ◽  
Nanocrystalline Copper ◽  
Average Grain Size ◽  
Angular Extrusion ◽  
Bulk Nanocrystalline

Bulk nanocrystalline copper and nickel (average grain size ~ 50 nm) with high purity and density were synthesized by equichannel angular extrusion (ECAE). Both nanohardness and microhardness measurements revealed a significant increase in hardness of the bulk sample. The tensile strength of these materials has been found to be 5-6 times higher than conventional forms and our experiments show that Cu is extremely stable up to temperatures of 100 oC and Ni to temperatures of 250 oC. The fracture toughness, measured by the value of JIC for nc-copper and nickel have been found to be 21.66 KJ/m2 and 12.13 KJ/m2, respectively which are high for these strength levels.

Mechanical Properties of E21 Ti3AlC-base Alloy

2006 ◽  
Vol 980 ◽  
Author(s):  
Hideki Hosoda ◽  
Tomonari Inamura ◽  
Kenji Wakashima
Keyword(s):  
Mechanical Properties ◽  
Base Alloy ◽  
The Body ◽  
Nominal Composition ◽  
Second Phase ◽  
Positive Temperature ◽  
Compression Tests ◽  
Octahedral Interstitial Site ◽  
Temperature Range ◽  
Average Grain Size

AbstractMechanical properties and phase constitution of an E21-type Ti3AlC-base alloy were investigated by compression tests in a temperature range from room temperature (RT) to 1273K, scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD). The unit cell of E21 Ti3AlC is constructed by ¡§L12 Ti3Al¡¨ and a carbon atom occupying the body-center octahedral-interstitial-site surrounded by the Ti atoms. The nominal composition of the alloy was chosen to be the stoichiometric composition of 60mol%Ti-20mol%Al-20mol%C. The alloy was synthesized by mechanical alloying using high purity elemental powders followed by hot pressing at 1473K for 3hrs. It was found by XRD and SEM that the alloy was mainly composed of E21 Ti3AlC in addition to Cr2AlC-type Ti2AlC precipitates as a second phase. The density of Ti3AlC is calculated to be 4.29g/cm3 based on the lattice parameter of 0.4134nm of E21. The average grain size was 2μm by SEM. By the compression tests, the 0.2% flow stress at the temperature range from RT to 1073K exceeded 1GPa. The yield stress is comparably higher than those of other E21 intermetallic carbides: at 1073K, 1084MPa for Ti3AlC, 50MPa for Mn3AlC and 135MPa for Fe3AlC. Besides, a weak positive temperature dependence of strength was observed where the peak temperature was around 900K. This suggests that a Kear-Wilsdorf type dislocation pinning mechanism may be activated. It is concluded that E21 Ti3AlC-base alloy shows promise for a new high-temperature light-weight structural material.

Microstructure Evolution of AZ91D Magnesium Alloy Semi-solid Billets Prepared by a New SIMA Method

2006 ◽  
Vol 116-117 ◽  
pp. 132-135 ◽  
Author(s):  
Ju Fu Jiang ◽  
Shou Jing Luo
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Magnesium Alloy ◽  
Ultimate Tensile Strength ◽  
Equal Channel Angular Extrusion ◽  
Isothermal Treatment ◽  
Az91d Magnesium Alloy ◽  
Average Grain Size ◽  
Semi Solid

By using equal channel angular extrusion (ECAE) as strain induced step in strain induced melt activated (SIMA) and completing melt activated step by using semi-solid isothermal treatment, a new SIMA method is introduced firstly. The results show that semi-solid billet with highly spheroidal and homogeneous grains with the average grain size of 20μm can be prepared by new SIMA method. High mechanical properties, such as ultimate tensile strength of 321.8MPa and elongation of 15.2% are obtained in magazine plate components thixoforged using semi-solid billet prepared by new SIMA.

Fabrication of Nanocrystalline TaSi2-SiC Composite by High Frequency Induction Heated Combustion Synthesis and Its Mechanical Properties.

2007 ◽  
Vol 534-536 ◽  
pp. 525-528 ◽  
Author(s):  
In Jin Shon ◽  
Dong Ki Kim ◽  
In Yong Ko ◽  
Jin Kook Yoon ◽  
Kyung Tae Hong
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Combustion Synthesis ◽  
High Frequency ◽  
Single Step ◽  
Combined Effects ◽  
Induced Current ◽  
Mechanical Pressure ◽  
Average Grain Size ◽  
High Frequency Induction

By the high frequency induction heated combustion synthesis (HFIHCS) method, dense nanostructured TaSi2-SiC composite was synthesized within 2 minutes and in a single step from powders of TaC and 3Si. Simultaneous combustion synthesis and densification were accomplished under the combined effects of an induced current and mechanical pressure. Highly dense TaSi2-SiC with relative density of up to 97% were produced under a 60MPa pressure and induced current. The average grain size and mechanical properties (hardness and fracture toughness) of the composite were investigated.

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