Processing and Characterization of Pure Nickel Sheets by Constrained Groove Pressing (CGP) Technique

2010 ◽  
Vol 667-669 ◽  
pp. 523-528 ◽  
Author(s):  
S.S.Satheesh Kumar ◽  
T. Raghu
Keyword(s):  
Mechanical Properties ◽  
Grain Refinement ◽  
Room Temperature ◽  
Considerable Increase ◽  
Vickers Microhardness ◽  
Deformation Behaviour ◽  
Pure Nickel ◽  
Size Evolution ◽  
Strain Magnitude

Pure nickel sheets are severe plastically deformed by constrained groove pressing technique at room temperature up to three passes. A total strain magnitude of 3.48 is imparted to the sheets and further processing is limited by initiation of surface microcracks. The grain size evolution studied by optical microscopy reveals significant grain refinement at the end of third pass evidently illustrating the effectiveness of groove pressing technique for grain refinement in sheet materials. Vickers microhardness measured during different stages of groove pressing process clearly describes the deformation behaviour in different segments of slant and flat regions. The change in mechanical properties of constrained groove pressed sheet is evaluated by room temperature tensile and microhardness tests. Results showed considerable increase in strength and hardness during initial passes followed by slight drop during third pass.

Structural and Mechanical Behaviour of Severe Plastically Deformed OFE Copper Processed by Constrained Groove Pressing Technique

2012 ◽  
Vol 710 ◽  
pp. 229-234
Author(s):  
S.S. Satheesh Kumar ◽  
T. Raghu
Keyword(s):  
Grain Refinement ◽  
Room Temperature ◽  
Vickers Microhardness ◽  
Deformation Behaviour ◽  
Sheet Material ◽  
Tensile Tests ◽  
Fine Grained ◽  
Marginal Gain ◽  
Ofe Copper ◽  
Deformation Homogeneity

Oxygen free electrolytic (OFE) grade copper sheets (5mm thick) are severe plastically deformed by constrained groove pressing technique (CGP) at room temperature up to three passes thereby imparting a total plastic strain of 3.48 throughout the sheet material. The revelation of significant grain refinement investigated by light microscopy in constrained groove pressed sheets markedly signifies the ability of CGP technique for processing fine grained sheet materials. Relatively higher grain refinement rates are observed during initial passes. Deformation homogeneity evaluated from Vickers microhardness measurements indicated inhomogeneous deformation behaviour during early stages of straining; however enhancement in deformation homogeneity is observed later. CGP processed sheets subjected to room temperature tensile tests showed significant increase in strength associated with drop in ductility. Marginal gain in ductility coupled with slight decrease in strength attributed to the dominance of dislocation recovery is observed after third pass.

Mechanical properties of nickel beryllides

1989 ◽  
Vol 4 (6) ◽  
pp. 1347-1353 ◽  
Author(s):  
T. G. Nieh ◽  
J. Wadsworth ◽  
C. T. Liu
Keyword(s):  
Crystal Structure ◽  
Mechanical Properties ◽  
Elastic Properties ◽  
Room Temperature ◽  
Vickers Microhardness ◽  
Interstitial Oxygen ◽  
Equiatomic Composition ◽  
Room Temperature Ductility ◽  
Hardness Increase ◽  
Microhardness Tester

The elastic properties of nickel beryllide have been evaluated from room temperature to 1000 °C. The room temperature modulus is measured to be 186 GPa, which is relatively low by comparison with other B2 aluminides such as NiAl and CoAl. Hardness measurements were carried out on specimens that had compositions over the range from 49 to 54 at. % Be, using both a Vickers microhardness tester and a nanoindentor. It was found that the hardness of NiBe exhibits a minimum at the equiatomic composition. This behavior is similar to that of aluminides of the same crystal structure, e.g., NiAl and CoAl. The effect of interstitial oxygen on the hardness of NiBe has also been studied and the results show that the presence of oxygen in NiBe can cause a significant increase in hardness. It is demonstrated that the hardness increase for the off-stoichiometric compositions is primarily caused by interstitial oxygen and can only be attributed partially to anti-site defects generated in off-stoichiometric compositions. Nickel beryllides appear to have some intrinsic room temperature ductility, as evidenced by the absence of cracking near hardness indentations.

Characterization of Hot-Pressed Silicon Nitride Ceramics with Alkoxide-Derived Oxide Mixtures As the Sintering Aid

1992 ◽  
Vol 287 ◽  
Author(s):  
Y. Sato ◽  
C. Sakurai ◽  
M. Ueki ◽  
K. Sugita
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Weight Ratio ◽  
Sintering Aids ◽  
Sintering Aid ◽  
Oxide Powders ◽  
Nitride Ceramics ◽  
Final Weight ◽  
Alkoxide Method

ABSTRACTA homogeneous mixture of Y2O3, CeO2 and MgO with a final weight ratio of 3:1: 2 was prepared by the alkoxide method. The powder mixture was then added into Si3N4 powder in amounts ranging from 4 to 12 wt%, andconsolidated by hot-pressing. Microstructure and mechanical properties of the sintered bodies were determined and compared to those of materials prepared by the conventional route of mixing the oxide powders as sintering aids individually in essentially same composition. The β-fraction (modification ratio) in same composition was higher in thesintered bodies made through the alkoxide method than those made through the conventional one. The room temperature flexural strength was maximized with 6wt% addition of the alkoxide derived oxide, whereas, 12wt% addition of the total oxide was required to maximize the strength by conventional processing.

scholarly journals Microstructural and Mechanical Characterization of Al-0.80Mg-0.85Si-0.3Zr Alloy

2017 ◽  
Vol 17 (4) ◽  
pp. 73-78 ◽  
Author(s):  
F. Kahrıman ◽  
M. Zeren
Keyword(s):  
Mechanical Properties ◽  
Automotive Industry ◽  
Room Temperature ◽  
Tensile Tests ◽  
Direct Chill ◽  
Peak Hardness ◽  
Casting Method ◽  
Industry Standard ◽  
Three Stages

Abstract In this study, Al-0.80Mg-0.85Si alloy was modified with the addition of 0.3 wt.-% zirconium and the variation of microstructural features and mechanical properties were investigated. In order to produce the billets, vertical direct chill casting method was used and billets were homogenized at 580 °C for 6 h. Homogenized billets were subjected to aging practice following three stages: (i) solution annealing at 550 °C for 3 h, (ii) quenching in water, (iii) aging at 180 °C between 0 and 20 h. The hardness measurements were performed for the alloys following the aging process. It was observed that peak hardness value of Al-0.80Mg-0.85Si alloy increased with the addition of zirconium. This finding was very useful to obtain aging parameters for the extruded hollow profiles which are commonly used in automotive industry. Standard tensile tests were applied to aged profiles at room temperature and the results showed that modified alloy had higher mechanical properties compared to the non-modified alloy.

Microstructures and Mechanical Properties of Solid-State Welded Steels

2021 ◽  
Vol 21 (9) ◽  
pp. 4877-4880
Author(s):  
Gyeong Woo Kim ◽  
Se Min Jeong
Keyword(s):  
Mechanical Properties ◽  
Solid State ◽  
Grain Refinement ◽  
Friction Welding ◽  
Vickers Microhardness ◽  
Rotation Speed ◽  
Base Material ◽  
Tensile Specimen ◽  
Refined Grains ◽  
Microstructures And Mechanical Properties

This study aimed to evaluate the soundness of solid-state welded steels. STS 430F alloy with a rod type was selected as experimental material, and the friction welding was conducted at a rotation speed of 2,000 RPM and upset length of 3 mm. The application of friction welding on STS 430F rods led to significant grain refinement in the welded zone (1.3 µm) compared to that observed in the base material (16.8 µm). The refined grains in the welds contributed to the development of the mechanical properties. In particular, the Vickers microhardness was increased by approximately 25% compared to the base material, and the fracture at the tensile specimen of the welds occurred at the base material zone and not in the welded zone, which suggests a soundly welded state on the STS 430F rods.

GROWTH AND CHARACTERIZATION OF A SEMIORGANIC NLO MATERIAL: L-HISTIDINE BARIUM CHLORIDE DIHYDRATE

2016 ◽  
Vol 2 (1) ◽  
pp. 26-30
Author(s):  
Beena T R
Keyword(s):  
Nonlinear Optical ◽  
Room Temperature ◽  
Vickers Microhardness ◽  
Second Harmonic ◽  
Barium Chloride ◽  
Nonlinear Optical Material ◽  
Solvent Evaporation Method ◽  
X Ray ◽  
Chloride Dihydrate

L-Histidine Barium Chloride dihydrate (LHBC), a semi organic nonlinear optical material was grown from aqueous solution by slow solvent evaporation method at room temperature.  The LHBC crystals were characterized by X-ray powder diffraction analysis.  The presence of functional groups was identified through Fourier Transform Infrared Spectroscopy.  Thermogravimetric and Differential Thermal Analysis confirm that the crystal is stable up to 269oC.  The mechanical properties of the grown crystals have been studied using Vickers microhardness test.  The second harmonic generation behavior of LHBC crystal was tested by Kurtz-Perry powder technique.

Preparation and Characterization of SiC/MoSi2 Composites from Powder Resulting from a Mechanical-Assistant Combustion Synthesis Method

2010 ◽  
Vol 105-106 ◽  
pp. 70-74
Author(s):  
Jian Guang Xu ◽  
Hui Qiang Li ◽  
Hou An Zhang
Keyword(s):  
Mechanical Properties ◽  
Cyclic Oxidation ◽  
Room Temperature ◽  
Synthesis Method ◽  
Pressureless Sintering ◽  
Sintering Process ◽  
Oxidation Properties ◽  
Mosi2 Composite

SiC reinforced MoSi2 composites have been successfully prepared by pressureless sintering from mechanical-assistant combustion synthesized powders. The sintering temperatures and holding time were 1500°C~1650°C at a heating rate of 10K/min and 1 hour, respectively. The microstructure and mechanical properties of the as-sintered composites were investigated. SEM micrographs of SiC/MoSi2 composites showed that SiC particles were homogeneously distributed in MoSi2 matrix. The Vickers hardness, flexural strength and fracture toughness of the SiC/MoSi2 composites were up to 15.50GPa, 468.7MPa and 9.35MPa•m1/2, respectively. The morphologies of fractured surface of the composites revealed the mechanism to improve mechanical properties of MoSi2 matrix. At last, the cyclic oxidation behavior of the composites was discussed. The results of this work showed that in situ SiC/MoSi2 composite powder prepared by MASHS technique could be successfully sintered via pressureless sintering process and significant improvement of room temperature mechanical and anti-oxidation properties could be achieved.

Influence of number of ECAP passes on microstructure and mechanical properties of AZ31 magnesium alloy

2012 ◽  
Vol 57 (3) ◽  
pp. 711-717 ◽  
Author(s):  
K. Bryła ◽  
J. Dutkiewicz ◽  
L. Litynska-Dobrzynska ◽  
L.L. Rokhlin ◽  
P. Kurtyka
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Grain Refinement ◽  
Vickers Microhardness ◽  
Az31 Alloy ◽  
Az31 Magnesium Alloy ◽  
Angular Pressing ◽  
Microstructure And Mechanical Properties ◽  
Transmission Electron

The aim of this work was to investigate the influence of the number of equal channel angular pressing (ECAP) passes on the microstructure and mechanical properties of AZ31 magnesium alloy. The microstructure after two and four passes of ECAP at 423 and 523 K was investigated by means of optical and transmission electron microscopy. The mechanical properties were carried out using Vickers microhardness measurements and compression test. The grain refinement in AZ31 alloy was obtained using ECAP routes down to 1,5 μm at 423 K. Processes of dynamic recrystallization during ECAP were observed. It was found that a gradual decrease of grain size occurs with the increasing of number of ECAP passes. The grain refinement increases mechanical properties at ambient temperature, such as Vickers microhardness and compression strength proportionally to d-0.5.

Microstructure and Properties Characterization of Polycrystalline Ni-Fe-Cr-Based Superalloy EP-718E after Electric Upsetting

2016 ◽  
Vol 721 ◽  
pp. 467-472 ◽  
Author(s):  
Lembit Kommel
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Energy Dispersive Spectrometry ◽  
Fatigue Testing ◽  
Tension Stress ◽  
Tension Testing ◽  
Electric Upsetting ◽  
Number Of Cycles ◽  
Cycles To Failure

The purpose of this study is to analyze the effect of electric upsetting on the microstructure defects eliminating and mechanical properties evolution of the Ni-Fe-Cr-based polycrystalline superalloy EP718E. The microstructure was examined by scanning electron microscope and energy dispersive spectrometry techniques. The material mechanical properties were characterized by nanoindentation, by tension testing of micro samples and high cycle fatigue testing at room temperature. The results show, that the microstructure defects on confluence of grain boundaries (depending on the processing stages) were step-by-step eliminated. The tension stress was lowered but elongation was increase. As a result of such changes in microstructure and mechanical properties of alloy the fatigue strength (δ-1) was increased from δ-1 = 300 MPa to δ-1 = 540 MPa and the number of cycles to failure was increased from N1 = 2·107 up to N4 = 4 x (2·107), respectively.

scholarly journals TEXTURE AND CHARACTERIZATION OF MECHANICAL PROPERTIES IN PURE NICKEL

2015 ◽  
Vol 9 (1) ◽  
pp. 23-28
Author(s):  
Srinivasa Vadayar K ◽  
Kumud Kant Mehta ◽  
Basava Narayana N
Keyword(s):  
Mechanical Properties ◽  
Pure Nickel
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