scholarly journals Spectroscopic and Mechanical Studies on the Fe-based Amorphous Alloy 2605SA1

2019 ◽  
Vol 54 (1) ◽  
Author(s):  
Agustín Cabral-Prieto ◽  
Juan Antonio Contreras-Vite ◽  
Irma García-Sosa ◽  
Noel Nava ◽  
Federico García-Santibáñez
Keyword(s):  
Phase Transition ◽  
Heat Treatment ◽  
Structural Changes ◽  
Amorphous State ◽  
Micro Hardness ◽  
Thermally Induced ◽  
Magnetic States ◽  
Vickers Micro Hardness ◽  
Brittle Alloy ◽  
Mechanical Studies

The Vickers micro-hardness of this alloy was unusually dependent on the heat treatment from 300 to 634K, inferring important micro-structural changes and the presence of amorphous grains before its phase transition. Once the alloy is crystallized, the microhardness is characteristic of a brittle alloy, the main problem of these alloys. Within the amorphous state, other properties like free-volume, magnetic states and Fe-Fe distances were followed by PALS and MS, respectively, to analyze those micro-structural changes, thermally induced, which are of paramount interest to understand their brittleness problem.    

scholarly journals Structural Changes of Nitrogen Ferrite After Aging in Temperature Interval up to 100 °С

2021 ◽  
Vol 44 (1) ◽  
pp. 28-33
Author(s):  
Tatyana MECHKAROVA ◽  
Yaroslav ARGIROV ◽  
Daniela SPASOVA ◽  
Aneliya STOYANOVA
Keyword(s):  
Heat Treatment ◽  
Surface Layer ◽  
Aging Process ◽  
Structural Changes ◽  
Electrochemical Corrosion ◽  
Micro Hardness ◽  
X Ray ◽  
Ferrite Structure ◽  
The Individual ◽  
Individual Grains

This paper aims to determine the extent of aging of nitrogen ferrite at temperatures below 100 °C and the structural and strength changes that occur in the process. The tests are carried out on samples of technically pure iron (Armco). The specimens are pre-deformed by tension and re-crystallisation heating to achieve a large-grain ferrite structure. A large-grained structure has been chosen to more accurately track the change in micro-hardness of the individual grains during the aging process. Nitric ferrite results from gas carbonitriding and subsequent hardening. Upon hardening, the samples are stored in a refrigerator, and then the surface layer formed is removed through electrochemical corrosion. Afterwards, aging heat treatment at temperatures below 100 °C is undertaken. After the aging process, micro-hardness of the individual grains is examined and X-ray structural analysis is performed.

scholarly journals Temperature-Dependent Nanomechanics and Topography of Bacteriophage T7

2018 ◽  
Vol 92 (20) ◽  
Author(s):  
Zsuzsanna Vörös ◽  
Gabriella Csík ◽  
Levente Herényi ◽  
Miklós Kellermayer
Keyword(s):  
Heat Treatment ◽  
Structural Changes ◽  
Molecular Mechanisms ◽  
Mechanical Stability ◽  
Structural Constraints ◽  
Thermally Induced ◽  
Force Microscopy ◽  
Partial Denaturation ◽  
Induced Changes ◽  
T7 Phage

ABSTRACT Viruses are nanoscale infectious agents which may be inactivated by heat treatment. The global molecular mechanisms of virus inactivation and the thermally induced structural changes in viruses are not fully understood. In this study, we measured the heat-induced changes in the properties of T7 bacteriophage particles exposed to a two-stage (65°C and 80°C) thermal effect, by using atomic force microscopy (AFM)-based nanomechanical and topographical measurements. We found that exposure to 65°C led to the release of genomic DNA and to the loss of the capsid tail; hence, the T7 particles became destabilized. Further heating to 80°C surprisingly led to an increase in mechanical stability, due likely to partial denaturation of the capsomeric proteins kept within the global capsid arrangement. IMPORTANCE Even though the loss of DNA, caused by heat treatment, destabilizes the T7 phage, its capsid is remarkably able to withstand high temperatures with a more or less intact global topographical structure. Thus, partial denaturation within the global structural constraints of the viral capsid may have a stabilizing effect. Understanding the structural design of viruses may help in constructing artificial nanocapsules for the packaging and delivery of materials under harsh environmental conditions.

Effects of Heat Treatment and Titanium Nitride (TiN) Coating Deposited by Sputtering Technique PVD on Duylos 2510 Tool Steel Substrate

2014 ◽  
Vol 493 ◽  
pp. 666-671
Author(s):  
Viktor Malau ◽  
Subagyo Subagyo ◽  
Supriyanto
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Wear Rate ◽  
Physical Properties ◽  
Tool Steel ◽  
Micro Hardness ◽  
Tin Coating ◽  
Tempering Temperature ◽  
Mechanical And Physical Properties ◽  
Vickers Micro Hardness

The objective of this research is to characterize the effects of heat treatment such as quenching, tempering and TiN coating on mechanical and physical properties of duylos 2510 steel. These mechanical properties include wear rate, hardness, impact toughness, whereas physical properties are microstructures. Duylos 2510 steel is a cold work tool steel and has chemical composition (wt %) of 1C; 0,6 Cr; 0,1 V; 1 Mn; 0,25 Si and 0,6 W.Quenching process has been conducted by heating the specimens on austenite temperature of 800 °C with the soaking time of 30 minutes and then cooling these specimens in oil medium. Tempering process was done at temperatures of 100, 200, 300, 400, 500 dan 600 °C with holding time of 2 hours.TiN coating has been deposited on substrates by sputtering technique of Physical Vapor Deposition at temperatures of 100, 150, 200 and 250 °C with sputtering time of 45 minutes. The mechanical and physical properties have been characterized by wear test, Vickers micro hardness test, Charpy impact test, and metallography test. This research was performed at room temperature and the major parameters of this research were tempering and sputtering temperatures.The results show that tempering temperature variations give significant modification of mechanical properties. In general, the Vickers micro-hardness decreases if tempering temperatures of the specimen increase. The highest Vickers micro-hardness of TiN coatings is 290 HV0,01 for the specimen having sputtering temperature of 200 °C. Wear rate and impact energy increase if tempering temperatures increase. The results also show that the Vickers micro-hardness of coated specimens is higher than the micro Vickers hardness of non-coated specimens

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

Evaluation of the Resistance of Individual Si Die to Cracking

1998 ◽  
Author(s):  
R. Berriche ◽  
R.K. Lowry ◽  
M.I. Rosenfield
Keyword(s):  
Thermal Cycling ◽  
Hardness Test ◽  
Mechanical Stresses ◽  
Test Method ◽  
Processing Conditions ◽  
Micro Hardness ◽  
Test Methodology ◽  
Vickers Micro Hardness

Abstract The present work investigated the use of the Vickers micro-hardness test method to determine the resistance of individual die to cracking. The results are used as an indicator of resistance to failure under the thermal and mechanical stresses of packaging and subsequent thermal cycling. Indentation measurements on die back surfaces are used to determine how changes in wafer backside processing conditions affect cracks that form around impressions produced at different loads. Test methodology and results obtained at different processing conditions are discussed.

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.

Effect of Heat Treatment on the Microstructure and Property of TiAl Alloys Prepared by Gas Atomization Powders

2013 ◽  
Vol 747-748 ◽  
pp. 497-501
Author(s):  
Na Liu ◽  
Zhou Li ◽  
Guo Qing Zhang ◽  
Hua Yuan ◽  
Wen Yong Xu ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Heat Treatment Temperature ◽  
Tial Alloy ◽  
Lamellar Microstructure ◽  
Treatment Temperature ◽  
Gas Atomization ◽  
Thermally Induced ◽  
Heat Treated ◽  
Fine Duplex ◽  
Step Heat Treatment

Powder metallurgical TiAl alloy was fabricated by gas atomization powders, and the effect of heat treatment temperature on the microstructure evolution and room tensile properties of PM TiAl alloy was investigated. The uniform fine duplex microstructure was formed in PM TiAl based alloy after being heat treated at 1250/2h followed by furnace cooling (FC)+ 900/6h (FC). When the first step heat treatment temperature was improved to 1360/1h, the near lamellar microstructure was achieved. The ductility of the alloy after heat treatment improved markedly to 1.2% and 0.6%, but the tensile strength decreased to 570MPa and 600MPa compared to 655MPa of as-HIP TiAl alloy. Post heat treatment at the higher temperature in the alpha plus gamma field would regenerate thermally induced porosity (TIP).

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