scholarly journals FEATURES OF ALLOYED A MATRYX OF WATER-DISPERSED IRON POWDERS

2021 ◽  
Vol 3 ◽  
pp. 226-231
Author(s):  
Ivanka Miteva ◽  
Ivan Vinev ◽  
Ivan Mitev
Keyword(s):  
Powder Metallurgy ◽  
Technological Process ◽  
Alloying Elements ◽  
Iron Matrix ◽  
Iron Powders ◽  
Dimensional Changes ◽  
Copper Nickel ◽  
Special Place ◽  
The Matrix

The publication examines the peculiarities of alloying a matrix of water-dispersed iron powders of the type ASC 100.29, AHC 100.29 and ABC 100.30. The possible ways of alloying in powder metallurgy are presented. The influence of the main alloying elements - copper, nickel, phosphorus, molybdenum, etc. was traced. on the technological process in the production of powder metallurgical details. A special place is given to the alloying elements intensifying the process of coagulation of the pores in the matrix during sintering - copper and phosphorus. Graphical dependences for the influence of copper on the dimensional changes of the iron matrix at different sintering temperatures are presented. 

scholarly journals Influence of alloying components on diffusion and bonding processes in powder materials

2021 ◽  
Vol 2131 (4) ◽  
pp. 042024
Author(s):  
M Egorov ◽  
R Egorova ◽  
A Atrohov ◽  
V Ekilik
Keyword(s):  
Powder Metallurgy ◽  
Rapid Development ◽  
Alloying Elements ◽  
Powder Materials ◽  
Iron Powders ◽  
Cast Steels ◽  
Wide Range ◽  
Aerospace Technology ◽  
Alloy Steels ◽  
Characteristic Features

Abstract At present, powder materials are used in practically all branches of industry, from medicine to aerospace technology. This is a wide range of materials ranging from constructional and instrumental materials and ending with special-purpose materials and medical implants. Powder metallurgy methods are most often used where the manufacture of products with desired properties is impossible using traditional methods: casting, stamping, etc. The production of all these materials is based on such basic operations as: obtaining starting materials, molding from these materials blanks of a given shape, size and strength, and sintering, intended for the final formation of the required properties and dimensions. The peculiarity of powder metallurgy technology allows creating a huge variety of developed technological schemes, which puts these technologies to a new level and allows for the rapid development of many industries. Alloying powder steels, in contrast to cast steels, has a number of characteristic features due to the specificity of their production. The structure of powder alloy steels and their properties depend on the methods of obtaining steels and technological features of their production. The following main methods of obtaining powder alloyed steels can be named: preparation of multicomponent mixtures of powders of iron and alloying elements and their subsequent processing; the use of alloyed iron powders, to which, if necessary, add carbon or other alloying elements; impregnation with liquid alloying metals or diffusion saturation of frameworks sintered from iron powders.

High Strength Sinter-Hardening Powder Metallurgy Alloys

2008 ◽  
Vol 51 ◽  
pp. 3-9 ◽  
Author(s):  
K.S. Hwang ◽  
M.W. Wu ◽  
Chia Cheng Tsai
Keyword(s):  
Tensile Strength ◽  
Powder Metallurgy ◽  
Cooling Rate ◽  
High Hardness ◽  
High Strength ◽  
Alloying Elements ◽  
Cooling Rates ◽  
The Matrix ◽  
Fast Cooling ◽  
The Cost

High strength and high hardness can be readily attained after sintering when sinter-hardening grade powder metallurgy alloys are used. However, fast cooling rates greater than 60°C/min are usually required. This increases the cost of the sintering equipment and maintenance. To lower the required minimum cooling rate, the homogeneity of the alloying elements in the matrix and the hardenability of the material must be improved. Among the various popular alloying elements, nickel and carbon are the two most non-uniformly distributed elements due to their repelling effect. It is found that to improve their homogenization, the addition of Cr and Mo can alleviate the repelling effect between Ni and C. As a result, weak Ni-rich/C-lean ferrite and austenite are eliminated and replaced by hard bainite and martensite. A tensile strength of 1323 MPa and a hardness of 39 HRC are attained in sinter-hardened Fe-3Cr-0.5Mo-4Ni-0.5C compacts without any quenching treatment.

High Temperature Mechanical Properties of Ni-Al-Cr Based Alloys with Refractory Alloying Elements

2006 ◽  
Vol 510-511 ◽  
pp. 358-361
Author(s):  
Won Yong Kim ◽  
Han Sol Kim ◽  
In Dong Yeo ◽  
Mok Soon Kim
Keyword(s):  
High Temperature ◽  
Volume Fraction ◽  
Lattice Parameter ◽  
Alloying Elements ◽  
Solid Solution Hardening ◽  
High Temperature Strength ◽  
High Temperature Mechanical Properties ◽  
Die Materials ◽  
The Matrix ◽  
Effective Role

We report on advanced Ni3Al based high temperature structural alloys with refractory alloying elements such as Zr and Mo to be apllied in the fields of die-casting and high temperature press forming as die materials. The duplex microstructure consisting of L12 structured Ni3Al phase and Ni5Zr intermetallic dispersoids was observed to display the microstructural feature for the present alloys investigated. Depending on alloying elements, the volume fraction of 2nd phase was measured to be different, indicating a difference in solid solubility of alloying elements in the matrix γ’ phase. Lattice parameter of matrix phase increased with increasing content of alloying elements. In the higher temperature region more than 973K, the present alloys appeared to show their higher strength compared to those obtained in conventional superalloys. On the basis of experimental results obtained, it is suggested that refractory alloying elements have an effective role to improve the high temperature strength in terms of enhanced thermal stability and solid solution hardening.

scholarly journals Particularities of structure formation of aluminum-copper composite materials manufactured by casting technology

2020 ◽  
pp. 116-121
Author(s):  
V. A. Kalinichenko ◽  
A. S. Kalinichenko ◽  
S. V. Grigoriev
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Structure Formation ◽  
Matrix Material ◽  
Matrix Alloy ◽  
Alloying Elements ◽  
Casting Technology ◽  
The Matrix ◽  
Reinforcing Material ◽  
Copper Composite

To create friction pairs operating in severe working conditions, composite materials are now increasingly used. Composite materials obtained with the use of casting technologies are of interest due to the possibility to manufacture wide range of compositions at low price compared to powder metallurgy. Despite the fact that many composite materials have been sufficiently studied, it is of interest to develop new areas of application and give them the properties required by the consumer. In the present work the composite materials on the basis of silumin reinforced with copper granules were considered. Attention was paid to the interaction between the matrix alloy and the reinforcing phase material as determining the properties of the composite material. The analysis of distribution of the basic alloying elements in volume of composite material and also in zones of the interphases interaction is carried out. The analysis of the possibility of obtaining a strong interphase zone of contact between the reinforcing component and the matrix material without significant dissolution of the reinforcing material is carried out.

scholarly journals Effect of Thermo-Mechanical Treatment on the Microstructure and Tensile Properties of the Fe-22Cr-5Al-0.1Y Alloy

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5696
Author(s):  
Hongyan Che ◽  
Yazhong Zhai ◽  
Yingjie Yan ◽  
Yongqing Chen ◽  
Wei Qin ◽  
...  
Keyword(s):  
Powder Metallurgy ◽  
Mechanical Treatment ◽  
Oxide Dispersion Strengthened ◽  
Fusion Reactors ◽  
Oxide Dispersion ◽  
Grain Sizes ◽  
Powder Metallurgy Process ◽  
The Matrix ◽  
Thermo Mechanical Treatment ◽  
Metallurgy Process

Oxide dispersion strengthened ferritic steel is considered an important structural material in fusion reactors due to its excellent resistance to radiation and oxidation. Fine and dispersed oxides can be introduced into the matrix via the powder metallurgy process. In the present study, large grain sizes and prior particle boundaries (PPBs) formed in the FeCrAlY alloy prepared via powder metallurgy. Thermo-mechanical treatment was conducted on the FeCrAlY alloy. Results showed that microstructure was optimized: the average grain diameter decreased, the PPBs disappeared, and the distribution of oxides dispersed. Both ultimate tensile strength and elongation improved, especially the average elongation increased from 0.5% to 23%.

Programmable Skins based on Core-Shell Microsphere/Nanotube/Polymer Composites

2015 ◽  
Vol 1800 ◽  
Author(s):  
Balaji Panchapakesan ◽  
Cagdas Onal ◽  
James Loomis
Keyword(s):  
Polymer System ◽  
Liquid Hydrocarbon ◽  
Core Shell ◽  
Stimuli Responsive ◽  
Electrically Conductive ◽  
Dimensional Changes ◽  
Stimuli Responsive Polymers ◽  
Thermally Responsive ◽  
New Findings ◽  
The Matrix

ABSTRACTIn this paper, we describe unique thermally responsive polymer system based on nanotube-elastomers dispersed with core-shell expanding microspheres (phase-change material). Upon thermal or infrared stimuli, liquid hydrocarbon cores encapsulated within the microspheres vaporize, expanding the surrounding shells and stretching the matrix. Microsphere transformation resulted in visible dimensional changes associated with macroscopic volume increase (>500%), reduction in density (>80%), and increase in elastic modulus (>675%). Additionally, electrically conductive nanotubes allowed for expansion dependent electrical responses. We present our new findings on expansion dependent superhydrophobicity in these materials and present some outlook and comparison of our stimuli responsive polymers with other material systems for future origami based applications.

scholarly journals EBSD Analysis of Metal Matrix Nanocomposite Microstructure Produced by Powder Metallurgy

Nanomaterials ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 878 ◽  
Author(s):  
Íris Carneiro ◽  
Filomena Viana ◽  
Manuel F. Vieira ◽  
José V. Fernandes ◽  
Sónia Simões
Keyword(s):  
Powder Metallurgy ◽  
Advanced Materials ◽  
Sintering Process ◽  
Electron Backscattered Diffraction ◽  
Matrix Microstructure ◽  
Metal Matrix Nanocomposite ◽  
The Matrix ◽  
Dislocation Annihilation ◽  
Metal Nanocomposites ◽  
Matrix Nanocomposite

The development of metal nanocomposites reinforced by carbon nanotubes (CNTs) remains a focus of the scientific community due to the growing need to produce lightweight advanced materials with unique mechanical properties. However, for the successful production of these nanocomposites, there is a need to consolidate knowledge about how reinforcement influences the matrix microstructure and which are the strengthening mechanisms promoting the best properties. In this context, this investigation focuses on the study of the reinforcement effect on the microstructure of an Ni-CNT nanocomposites produced by powder metallurgy. The microstructural evolution was analysed by electron backscattered diffraction (EBSD). The EBSD results revealed that the dispersion/mixing and pressing processes induce plastic deformation in the as-received powders. The dislocation structures produced in those initial steps are partially eliminated in the sintering process due to the activation of recovery and recrystallization mechanisms. However, the presence of CNTs in the matrix has a significant effect on the dislocation annihilation, thus reducing the recovery of the dislocation structures.

scholarly journals Grain Refinement of Ti-15Mo-3Al-2.7Nb-0.2Si Alloy with the Rotation of TiB Whiskers by Powder Metallurgy and Canned Hot Extrusion

Metals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 126 ◽  
Author(s):  
Jiabin Hou ◽  
Lin Gao ◽  
Guorong Cui ◽  
Wenzhen Chen ◽  
Wencong Zhang ◽  
...  
Keyword(s):  
Powder Metallurgy ◽  
Tensile Test ◽  
Grain Refinement ◽  
Hot Extrusion ◽  
Dislocation Motion ◽  
Continuous Dynamic Recrystallization ◽  
Grain Sizes ◽  
The Matrix ◽  
Continuous Dynamic

In situ synthesized TiB whiskers (TiBw) reinforced Ti-15Mo-3Al-2.7Nb-0.2Si alloys were successfully manufactured by pre-sintering and canned hot extrusion via adding TiB2 powders. During pre-sintering, most TiB2 were reacted with Ti atoms to produce TiB. During extrusion, the continuous dynamic recrystallization (CDRX) of β grains was promoted with the rotation of TiBw, and CDRXed grains were strongly inhibited by TiBw with hindering dislocation motion. Eventually, the grain sizes of composites decreased obviously. Furthermore, the stress transmitted from the matrix to TiBw for strengthening in a tensile test, besides grain refinement. Meanwhile, the fractured TiBw and microcracks around them contributed to fracturing.

scholarly journals Are Large Particles of Iron Detrimental to Properties of Powder Metallurgy Steels?

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 431
Author(s):  
Ahmed Abdallah ◽  
Mahdi Habibnejad-Korayem ◽  
Dmitri V. Malakhov
Keyword(s):  
Powder Metallurgy ◽  
Apparent Density ◽  
Heavy Tail ◽  
Number Density ◽  
Iron Powders ◽  
Distribution Histogram ◽  
Compositional Uniformity ◽  
Large Particles ◽  
Size Distribution Histogram ◽  
Sintered Materials

It is experimentally shown that a removal of particles exceeding 100 microns in size from iron powders typically used in the fabrication of medium density powder metallurgy steels has a weak effect on apparent density, flowability and compressibility of blends as well as on density and strength of green bodies. An elimination of such particles, i.e., cutting off a heavy tail of a size distribution histogram at the 100 μm threshold, improves a compositional uniformity of sintered materials, but has no noticeable beneficial effect upon the strength of a final product, which is likely be determined by a fraction of pores and their shapes. A presence of soft pearlitic inclusions hardly matters unless their number density becomes so large that a 3D continuity (integrity) of a hard martensitic matrix is lost. This finding suggests that such an expensive preparatory step as sieving away large particles from as-received mixtures would bear no technological advantages. It was experimentally found that an attempt to lower the threshold below 100 μm noticeably worsened apparent density, flowability and compressibility.

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