Formation of Bulk Metal Ingots with Homogeneous Fine-Grained Structure Using Novel Semisolid Casting Technique

2006 ◽  
Vol 116-117 ◽  
pp. 406-409
Author(s):  
N.K. Tolochko ◽  
V.I. Timoshpolski ◽  
A.S. Kalinichenko ◽  
Yu.A. Shienok
Keyword(s):  
Partial Melting ◽  
Casting Method ◽  
Bulk Metal ◽  
Casting Technique ◽  
Fine Grained ◽  
Ingot Structure ◽  
Fine Grained Structure ◽  
Semisolid Casting

Novel semisolid casting method to produce bulk metal ingots with homogeneous fine-grained structure is proposed. In the method, the fine-grained particles are subjected to partial melting and compacting. As a result, the ingot structure is constituted mainly by fine-grained particles bonded by inerlayers of solidified melt.

Fabrication of Metal Matrix Nanocomposites

2009 ◽  
Vol 79-82 ◽  
pp. 425-428 ◽  
Author(s):  
N.K. Tolochko ◽  
A.A. Andrushevich ◽  
Yu.A. Shienok
Keyword(s):  
Partial Melting ◽  
Metal Matrix ◽  
Model Systems ◽  
Homogeneous Structure ◽  
Metal Matrix Nanocomposites ◽  
Casting Technique ◽  
Cast Composites ◽  
Matrix Nanocomposites ◽  
Semisolid Casting

Novel semisolid casting technique allowing producing the cast composites with highly homogeneous structure is suggested. In according with this technique specially prepared metal bil-lets containing reinforcing nanoparticles are subjected to partial melting and compacting and fol-lowing solidifying. Some model systems were used in order to demonstrate the potential possibili-ties of this technique in principle.

scholarly journals Effect of Microstructure and Notches on the Fracture Toughness of Medium Carbon Steel

1970 ◽  
Vol 3 (1) ◽  
pp. 15-22 ◽  
Author(s):  
SK Nath ◽  
Uttam Kr Das
Keyword(s):  
Fracture Toughness ◽  
Carbon Steel ◽  
Tensile Specimen ◽  
Medium Carbon Steel ◽  
Notch Angle ◽  
Medium Carbon ◽  
Fine Grained ◽  
Keywords Fracture ◽  
Fine Grained Structure ◽  
Marine Engineering

Fracture toughness (K1C) of medium carbon steel (0.5% C) has been determined by round notched tensile specimen. Two notch diameters (5.6mm and 4.2mm) and three notch angles (α) namely 45°, 60° and 75° have been used to observe the effect of notch diameters and notch angle on fracture toughness of the steel. By heat treatment the microstructure of the steel is also varied and its effect on the fracture toughness is also observed. It has been found that fine grained structure improves fracture toughness. Lower notch diameter and higher notch angle show higher value of K1C. Keywords: Fracture toughness, microstructure, notch, heat treatmentDOI: 10.3329/jname.v3i1.925 Journal of Naval Architecture and Marine Engineering 3(2006) 15-22

A Study on Nanocrystalline Nickel Parts Prepared by Jet Electrodeposition

2010 ◽  
Vol 37-38 ◽  
pp. 64-67
Author(s):  
Jin Song Chen ◽  
Yin Hui Huang ◽  
Bin Qiao ◽  
Jian Ming Yang ◽  
Yi Qiang He
Keyword(s):  
Dimensional Accuracy ◽  
Processing Parameters ◽  
X Ray Diffraction ◽  
Scanning Microscope ◽  
Nanocrystalline Nickel ◽  
X Ray ◽  
Fine Grained ◽  
Average Grain Size ◽  
Jet Electrodeposition ◽  
Fine Grained Structure

The principles of jet electrodeposition orientated by rapid prototyping were introduced. The nanocrystalline nickel parts with simple shape were fabricated using jet electrodeposition. The microstructure and phase transformation of nanocrystalline nickel were observed under the scanning microscope and X-ray diffraction instrument. The results show that the jet electrodeposition can greatly enhance the limited current density, fine crystalline particles and improve deposition quality. The nickel parts prepared by jet electrodeposition own a fine-grained structure (average grain size 25.6nm) with a smooth surface and high dimensional accuracy under the optimum processing parameters.

Electrodeposited Nanocrystalline Nickel Parts

2012 ◽  
Vol 201-202 ◽  
pp. 1102-1105
Author(s):  
Jin Song Chen ◽  
Jian Ming Yang
Keyword(s):  
Rapid Prototyping ◽  
Dimensional Accuracy ◽  
Processing Parameters ◽  
Nanocrystalline Nickel ◽  
Fine Grained ◽  
Average Grain Size ◽  
Machined Parts ◽  
Jet Electrodeposition ◽  
Fine Grained Structure ◽  
Metallic Parts

The principles of jet electrodeposition orientated by rapid prototyping were introduced , The nanocrystalline nickel parts with simple shape were fabricated using jet electrodeposition oriented by rapid prototyping. The microstructure and phase transformation of nanocrystalline nickel were observed under the scanning microscope and X-ray diffraction instrument . The results show that the successful fabrication of metallic parts demonstrates the potential of the jet electrodeposition process for prototyping technology . The jet electrodeposition can greatly enhance the limited current density, fine crystalline particles and improve deposition quality. The nickel parts prepared by jet electrodeposition own a fine-grained structure( average grain size 25.6nm) with a smooth surface and high dimensional accuracy under the optimum processing parameters..The dimensional accuracy as well as the surface quality of metallic parts and tools manufactured using jet electrodeposition techniques still lag far behind those of conventionally machined parts.

Structure, Texture and Mechanical Properties through the Section of the Hot-Extruded Tube of Titanium Alloy PT-1M

2020 ◽  
Vol 989 ◽  
pp. 139-144 ◽  
Author(s):  
F.V. Vodolazskiy ◽  
N.A. Barannikova ◽  
Anatoly G. Illarionov
Keyword(s):  
Titanium Alloy ◽  
Extrusion Direction ◽  
Hot Extrusion ◽  
Tangential Direction ◽  
Primary Recrystallization ◽  
Recrystallization Temperature ◽  
Fine Grained ◽  
Surface Areas ◽  
Α Phase ◽  
Fine Grained Structure

The study considers the formation of the structure, texture, and hardness of hot extruded tube of titanium alloy PT-1M. It is shown that hot extrusion at 840 °C, which is higher than the α-phase recrystallization temperature, results to the development of dynamic and primary recrystallization processes and ensures the formation of homogeneous and fine-grained structure through-out the cross section with a two-component tangential texture (0001)TD<100>ED+(0001)TD<110>ED (TD – tangential direction, ED – extrusion direction) and hardness of 155 HV. It has been established that a higher cooling rate of the surface areas of the tube after extrusion results to a less active development of recrystallization processes, which lead to the formation of a finer granular structure near the outer surface. This weakens recrystallization component of (0001)TD<110>ED, compared to other areas of the tube.

The Effect of Preliminary Mechanical Activation on the Structure and Mechanical Properties of Ni3Al+B Material Obtained by SPS

2017 ◽  
Vol 743 ◽  
pp. 19-24 ◽  
Author(s):  
Lilia I. Shevtsova ◽  
Anatoliy A. Bataev ◽  
Vyacheslav I. Mali ◽  
Maksim A. Esikov ◽  
Veronika V. Sun Shin Yan ◽  
...  
Keyword(s):  
Mechanical Activation ◽  
Bending Strength ◽  
Stoichiometric Composition ◽  
Initial Mixture ◽  
Optical Microscope ◽  
Fine Grained ◽  
Plasma Sintering ◽  
Fine Grained Structure ◽  
Spark Plasma ◽  
Almost All

In the present study, a mixture of powders (87.9 at.% Ni, 12 at.% Al, 0.1 at.% B) was used as the initial material to produce sintered Ni3Al + B alloy. Spark Plasma Sintering (SPS) method was used to compact the powder. The powder mixtures were previously prepared in two ways: mixing the initial powders in a mortar (М1) and mechanical activation (М2). The microstructure was observed using optical microscope (OM). The addition of small amount of boron to the initial mixture of nickel and aluminum improves the density of the sintered Ni3Al intermetallic compound (98.8%). The results of density, bending and microhardness tests showed, that the provisional three-minute mechanical activation improves almost all properties of the sintered material. The compact obtained by SPS by M2 contributes to the formation of a homogeneous fine-grained structure of the material. It leads to further increase in flexural bending strength up to 2200 MPa. This value is almost 8 times the strength of the intermetallic Ni3Al stoichiometric composition obtained by SPS.

scholarly journals STRUCTURE AND PROPERTIES OF AZ31 MAGNESIUM ALLOY AFTER COMBINATION OF HOT EXTRUSION AND ECAP

2017 ◽  
Vol 23 (3) ◽  
pp. 222 ◽  
Author(s):  
Ondřej Hilšer ◽  
Stanislav Rusz ◽  
Wojciech Maziarz ◽  
Jan Dutkiewicz ◽  
Tomasz Tański ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Hot Extrusion ◽  
Az31 Magnesium Alloy ◽  
Initial State ◽  
Fine Grained ◽  
Angular Pressing ◽  
Ecap Process ◽  
Average Grain Size ◽  
Fine Grained Structure

<p>Equal channel angular pressing (ECAP) method was used for achieving very fine-grained structure and increased mechanical properties of AZ31 magnesium alloy. The experiments were focused on the, in the initial state, hot extruded alloy. ECAP process was realized at the temperature 250°C and following route Bc. It was found that combination of hot extrusion and ECAP leads to producing of material with significantly fine-grained structure and improves mechanical properties. Alloy structure after the fourth pass of ECAP tool with helix matrix 30° shows a fine-grained structure with average grain size of 2 µm to 3 µm and high disorientation between the grains. More experimental results are discussed in this article.</p>

scholarly journals Microstructure features of the BST/(Mg, Ln)-ceramic

2021 ◽  
pp. 2160005
Author(s):  
K. P. Andryushin ◽  
A. V. Nagaenko ◽  
S. V. Khasbulatov ◽  
L. A. Shilkina ◽  
E. V. Glazunova ◽  
...  
Keyword(s):  
Solid Solutions ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Functional Materials ◽  
Ceramic Technology ◽  
Phase Synthesis ◽  
Fine Grained ◽  
Average Grain Size ◽  
Crystallite Sizes ◽  
Fine Grained Structure

Solid solutions of the composition Ba[Formula: see text](Mg, Ln)[Formula: see text]Sr[Formula: see text]TiO3 ([Formula: see text] = 0.01; 0.025; 0.04; [Formula: see text] = 0.20; 0.50; 0.80; Ln = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tu, Yb) were prepared by two-stage solid-phase synthesis followed by sintering using conventional ceramic technology. The influence of rare-earth elements on the microstructure of the prepared ceramic samples was investigated. It was found that regardless of the type of modifiers introduced, the grain landscape of the studied solid solutions with different amounts of SrTiO3 is refined (in the initial system, the average grain size, [Formula: see text], at [Formula: see text] = 0.20 is 6 [Formula: see text]m; at [Formula: see text] = 0.50 is 4 [Formula: see text]m; at [Formula: see text] = 0.80 is 18 [Formula: see text]m) to crystallite sizes not exceeding (2–3) [Formula: see text]m, and compacted. The using of mechanical activation procedures leads to an even greater decrease in the size and an increase in the density of ceramics. The increasing in the concentration of modifiers in each group (within the considered range of dopant variation) against the background of such a fine-grained structure has little effect on the dynamics of changes in [Formula: see text]. It is concluded that it is advisable to use the data obtained in the development of functional materials based on BST/(Mg, Ln) and devices with the participation of these compositions.

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