Magnetic Characteristics of CuCr2S4Nanospinels Obtained by Mechanical Alloying and Heat Treatment

The effect of heat treatment on the structure and magnetic properties of Sm-Fe alloys obtained by mechanical alloying was investigated. The crystallization temperature of Sm2Fe17, an amorphous alloy obtained by mechanical alloying, was determined using differential scanning calorimetry. Based on these results, various samples were annealed at different isothermal holding temperatures, and those with the best magnetic properties were found. Experimental studies show that decreasing the isothermal holding temperature from 750 °C to 630 °C increases magnetic characteristics nearly four times. The saturation magnetization, romance and coercivity of the Sm2Fe17 powder were 121 emu/g, 28.5 emu/g and 800 Oe, respectively.

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Physical methods of research and monitoring

Industrial laboratory Diagnostics of materials ◽

10.26896/1028-6861-2019-85-1-i-35-44 ◽

2019 ◽

Vol 85 (1(I)) ◽

pp. 35-44

Author(s):

S. G. Sandomirski

Keyword(s):

Heat Treatment ◽

Coercive Force ◽

Remanent Magnetization ◽

Structural Changes ◽

Mechanical Load ◽

Magnetic Hysteresis ◽

Steel Structures ◽

Magnetic Characteristics ◽

Magnetic Parameters ◽

Saturation Intensity

The main magnetic parameters sensitive to the structure of steels are the parameters of their saturation loop of magnetic hysteresis: the coercive force Hcs and remanent magnetization Mrs. The saturation magnetization or saturation intensity Mr is most sensitive to the phase composition of steels. The variety of steel grades and modes of technological treatment (e.g., heat treatment, mechanical load) determined the use of magnetic structurescopy and magnetic characteristics — the coercive force Hc, remanent magnetization Mr , and specific hysteresis losses Wh on the subloops of the magnetic hysteresis of steels — as control parameters in diagnostics of the stressed and structural states of steel structures and pipelines. It has been shown that changes in Hc, Mr , and Wh are more sensitive to structural stresses and structures of steels than the parameters of the saturation hysteresis loop of magnetic hysteresis (Hcs, Mrs, and Mrs). The formulas for calculating Hc, Mr and Wh are presented to be used for estimation of changes in the parameters upon heat treatment of steels. Features of the structural sensitivity of the subloop characteristics and expediency of their use for magnetic structural and phase analyzes are determined. Thus, the range of changes in Ìr attributed to the structural changes in steels upon gradual Hm decrease is many times wider compared to the range of possible changes in Mrs under the same conditions. Conditions (relations between the magnetic parameters) and recommendations regarding the choice of the field strength Hm are given which provide the justified use of Hc, Mr and Wh parameters in magnetic structurescopy

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Mechanical alloying and heat treatment of iron silicide powders

Metal Powder Report ◽

10.1016/s0026-0657(01)80745-1 ◽

2001 ◽

Vol 56 (12) ◽

pp. 39

Keyword(s):

Heat Treatment ◽

Mechanical Alloying ◽

Iron Silicide

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Influence of V and Heat Treatment on Characteristics of WMoNbTaV Refractory High-Entropy Alloy Coatings by Mechanical Alloying

Coatings ◽

10.3390/coatings11030265 ◽

2021 ◽

Vol 11 (3) ◽

pp. 265

Author(s):

Chun-Liang Chen ◽

Sutrisna

Keyword(s):

Heat Treatment ◽

Mechanical Alloying ◽

Annealing Treatment ◽

High Energy ◽

304 Stainless Steel ◽

Homogeneous Distribution ◽

High Entropy Alloy ◽

Solid Solution Phase ◽

High Entropy ◽

Steel Substrates

Refractory high-entropy alloy (RHEA) is one of the most promising materials for use in high-temperature structural materials. In this study, the WMoNbTaV coatings on 304 stainless steel substrates has been prepared by mechanical alloying (MA). Effects of V addition and subsequent heat treatment on properties of the WMoNbTaV coatings were investigated. The results show that the RHEA coatings with nanocrystalline body-centered cubic (BCC) solid-solution phase were generated by the mechanical alloying process. The presence of the V element promotes a uniform microstructure and homogeneous distribution of composition in the RHEA coatings due to improving alloying efficiency, resulting in an increase of hardness. After the annealing treatment of the RHEA coatings, microstructure homogeneity was further enhanced; however, the high affinity of Ta for oxygen causes the formation of Ta-rich oxides. Annealing also removes strain hardening generated by high-energy ball milling and thus decreases the hardness of the RHEA coating and alters microstructure evolution and mechanical properties.

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Investigation of Microstructure and Property of Fe3Al/Al2O3 Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.150-151.1409 ◽

2010 ◽

Vol 150-151 ◽

pp. 1409-1412 ◽

Cited By ~ 1

Author(s):

Tao Jiang

Keyword(s):

Heat Treatment ◽

Phase Composition ◽

Mechanical Alloying ◽

Sintering Process ◽

Composite Powders ◽

Al2o3 Composite ◽

Al2o3 Phase ◽

The Mean ◽

Xrd Patterns ◽

Al2o3 Matrix

The Fe3Al/Al2O3 composites were fabricated by pressureless sintering process. The Fe3Al intermetallics compounds powders were fabricated by mechanical alloying and heat treatment, then the Fe3Al powders and Al2O3 powders were mixed and the Fe3Al/Al2O3 composite powders were prepared, so the Fe3Al/Al2O3 composites were fabricated by sintering process at 1700oC for 2h. The phase composition and microstructure of Fe3Al intermetallics compounds powders produced by mechanical alloying and heat treatment were investigated. The phase composition, microstructure and mechanical properties of the Fe3Al/Al2O3 composites sintered bulks were investigated. The XRD patterns results showed that there existed Fe3Al phase and Al2O3 phase in the sintered composites. The Fe3Al/Al2O3 composites sintered bulks exhibited the homogenous and compact microstructure, the Fe3Al particles were homogenously distributed in the Al2O3 matrix, the mean particles size of Fe3Al intermetallics was about 3-5μm. The Fe3Al/Al2O3 composites exhibited more homogenous and compact microstructure with the increase of Fe3Al content in the Al2O3 matrix. The density and relative density of the Fe3Al/Al2O3 composites increased gradually with the increase of Fe3Al content. The fracture strength and fracture toughness of the Fe3Al/Al2O3 composites increased gradually with the increase of Fe3Al content. The elastic modulus and hardness (HRA) of the Fe3Al/Al2O3 composites decreased gradually with the increase of Fe3Al content.

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