Alternative approaches used to assess structural changes of natural zircon caused by heat treatment

2018 ◽  
Vol 532 ◽  
pp. 42-47 ◽  
Author(s):  
L.T.T. Huong ◽  
N.T.M. Thuyet ◽  
T.L. Phan ◽  
N. Tran ◽  
D.N. Toan ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Structural Changes ◽  
Natural Zircon ◽  
Alternative Approaches

Physical methods of research and monitoring

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

Heat Treatment Influence on the Corrosion Resistance of a Cu-Al-Fe-Mn Bronze

2018 ◽  
Vol 69 (5) ◽  
pp. 1055-1059 ◽  
Author(s):  
Mariana Ciurdas ◽  
Ioana Arina Gherghescu ◽  
Sorin Ciuca ◽  
Alina Daniela Necsulescu ◽  
Cosmin Cotrut ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Structural Changes ◽  
Heating Temperature ◽  
Galvanic Corrosion ◽  
Cooling Water ◽  
Open Circuit ◽  
Water Quenching ◽  
Heat Treated ◽  
Different Temperatures

Aluminium bronzes are exhibiting good corrosion resistance in saline environments combined with high mechanical properties. Their corrosion resistance is obviously confered by the alloy chemical composition, but it can also be improved by heat treatment structural changes. In the present paper, five Cu-Al-Fe-Mn bronze samples were subjected to annealing heat treatments with furnace cooling, water quenching and water quenching followed by tempering at three different temperatures: 200, 400 and 550�C. The heating temperature on annealing and quenching was 900�C. The structure of the heat treated samples was studied by optical and scanning electron microscopy. Subsequently, the five samples were submitted to corrosion tests. The best resistance to galvanic corrosion was showed by the quenched sample, but it can be said that all samples are characterized by close values of open-circuit potentials and corrosion potentials. Concerning the susceptibility to other types of corrosion (selective leaching, pitting, crevice corrosion), the best corrosion resistant structure consists of a solid solution, g2 and k compounds, corresponding to the quenched and 550�C tempered sample.

Chemical and structural changes of 70Li2S-30P2S5 solid electrolyte during heat treatment

2017 ◽  
Vol 310 ◽  
pp. 50-55 ◽  
Author(s):  
Yasuhito Aoki ◽  
Kengo Ogawa ◽  
Takeshi Nakagawa ◽  
Yuichi Hasegawa ◽  
Yoko Sakiyama ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Solid Electrolyte ◽  
Structural Changes

scholarly journals Structural changes in clays subjected to heat treatment: an analysis by structural refinement using the Rietveld method

2021 ◽  
Vol 67 (6 Nov-Dec) ◽  
Author(s):  
Mauro Quiroga Agurto ◽  
Elvira Leticia Zeballos Velásquez ◽  
Felipe Americo Reyes Navarro
Keyword(s):  
Heat Treatment ◽  
Structural Changes ◽  
Rietveld Method ◽  
Mineralogical Composition ◽  
Structural Factors ◽  
Expansive Clay ◽  
Structural Refinement ◽  
Weight Percentage ◽  
Before And After ◽  
Cerro De Pasco

Structural factors in clays influence their physical properties. Therefore, it is particularly important to understand the effects of heat treatment on the structure of the material during the ceramic process. In this work, we have analyzed clays from quarries in the Cerro de Pasco region, Peru, to evaluate their characteristics and the structural changes produced by heating, particularly in the interlaminar region. The samples were thermally treated between 150 oC and 800 oC with intervals of 50 oC. To evaluate the structural changes produced by temperature, X-ray diffraction were carried out before and after each heat treatment. The qualitative analysis of the measurements allowed to identify the mineralogical composition of the samples, finding phases of calcium montmorillonite, kaolinite, illite and quartz. The quantitative analysis by the Rietveld method found structural changes, particularly in the Ca-montmorillonite expansive clay. It was also possible to determine the decrease in the weight percentage of the kaolinite until the collapse of its structure between 450 °C and 500 °C. The illite presented greater thermal stability, with slight variations in its weight percentage during heat treatment, without compromising its structure. Although the quartz phase did not show relevant structure changes, it slightly increased its weight percentage with increasing temperature.

scholarly journals Influence of the energy electron beam exposure regimes on the structure and mechanical properties of composite coatings

2020 ◽  
pp. 23-27
Author(s):  
T.A. Krylova ◽  
◽  
Y.A. Chumakov ◽  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Wear Resistance ◽  
Electron Beam ◽  
Structural Changes ◽  
Composite Coatings ◽  
Initial State ◽  
Austenitic Structure ◽  
Solid Carbide ◽  
Soft Ferrite

The effect of heat treatment on the structure and properties of composite coatings based on chromium carbide with titanium carbide fabricated by non-vacuum electron beam cladding without has been studied. It was shown that tempering leads to a decrease in microhardness and wear resistance, which is associated with the decomposition of the austenitic structure with the formation of a soft ferrite-carbide structure. The post heat treatment tempering was showed to decrease of microhardness and wear resistance, which leads to the decomposition of the austenitic structure with the formation of a soft ferrite-carbide structure. The bulk quenching of coatings after tempering leads to an increase in microhardness comparable to the values of microhardness in the initial state after electron beam cladding, due to the formation of high hard martensite. The wear resistance of composite coatings after tempering is lower than after cladding due to brittle martensite, which is not able to hold solid carbide particles. The composite coatings obtained at the optimal processing conditions have a combination of improved properties and do not require additional heat treatment, resulting in structural changes, causing a decrease in mechanical properties.

Structural changes in the lamellar eutectic Al-Al2Cu during heat treatment

1974 ◽  
Vol 30 (4) ◽  
pp. 691-703 ◽  
Author(s):  
Abraham D. Banchik ◽  
Alberto F. Bonfiglioli
Keyword(s):  
Heat Treatment ◽  
Structural Changes ◽  
Lamellar Eutectic
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