Magnetron Sputtering High Temperature Mo-Al2O3 Cermet Solar Selective Coatings

2007 ◽  
Vol 546-549 ◽  
pp. 1773-1776 ◽  
Author(s):  
Xin Kang Du ◽  
Cong Wang ◽  
Tian Min Wang ◽  
Bu Liang Chen ◽  
Long Zhou ◽  
...  
Keyword(s):  
Room Temperature ◽  
Annealing Temperature ◽  
Vacuum Annealing ◽  
Layer Structure ◽  
Steel Substrate ◽  
Annealing Treatment ◽  
Solar Absorptance ◽  
Selective Coating ◽  
Before And After ◽  
Different Temperatures

Based on double cermet layer structure, Mo-Al2O3 cermet solar selective coating was prepared on stainless steel substrate. A solar absorptance of 0.92 and normal emittance of 0.19 at room temperature have been achieved. Vacuum annealing treatment was done and its influences on the solar selective performance was discussed. Absorptance changed between 0.90 and 0.92 under the selected annealing temperature range of 350-800°C, and emittance varied from 0.19 to 0.23 when heated at 650°C. The microstructures before and after annealing process at different temperatures were investigated.

Effect of Annealing on the Properties of Surface Nanocrystallized CP-Ti

2011 ◽  
Vol 695 ◽  
pp. 162-165
Author(s):  
Cong Hui Zhang ◽  
Xiao Mei He ◽  
Xin Zhe Lan ◽  
Xi Cheng Zhao
Keyword(s):  
Corrosion Resistance ◽  
Polarization Curve ◽  
Annealing Temperature ◽  
Vacuum Annealing ◽  
Optical Microscope ◽  
Nanostructured Surface ◽  
Before And After ◽  
Different Temperatures ◽  
Cp Ti ◽  
Better Than

Vacuum annealing was carried out for the SMAT treated CP-Ti sample at different temperatures. The structure and the properties of the SMAT sample before and after the annealing were analyzed by means of the optical microscope, hardness and polarization curve testing. The results show that, when the annealing temperature of surface nanocrystallized CP-Ti treated CP-Ti (SMAT) was below 350°C, the microstructure and hardness of nanostructured surface was stability, and its corrosion resistance was improved compared to non-annealing one. In particular, the corrosion resistance at 150°C was better than that of the original CP-Ti.

Parameters for Nitrogen Diffusion in Ni, Ti, and Al Obtained from Implanted Bilayers

1992 ◽  
Vol 279 ◽  
Author(s):  
K. K. Bourdelle ◽  
D. O. Boerma
Keyword(s):  
Nuclear Reaction ◽  
Room Temperature ◽  
Vacuum Annealing ◽  
Nitride Layer ◽  
Nuclear Reaction Analysis ◽  
Nitrogen Diffusion ◽  
Depth Profiles ◽  
Solid Interface ◽  
Before And After ◽  
Concentration Depth Profiles

ABSTRACTNi foils and samples consisting of bilayers of Ni or Fe on Al, Ti or Si were implanted at room temperature with 15N+ ions to fluences of around 1×l017 N/cm2. The concentration depth profiles of 15N were determined with nuclear reaction analysis before and after vacuum annealing. It was found that the penetrability for N atoms of the surface and the solid/solid interface plays an important role in the N redistribution during implantation or annealing. The formation of a nitride layer or nitride clusters in Ni and Fe was deduced. Parameters for N migration determined for the metals under investigation are discussed in terms of models.

scholarly journals Do Rescuers’ Physiological Responses and Anxiety Influence Quality Resuscitation under Extreme Temperatures?

2020 ◽  
Vol 17 (12) ◽  
pp. 4241 ◽  
Author(s):  
José Luis Martin-Conty ◽  
Francisco Martin-Rodríguez ◽  
Juan José Criado-Álvarez ◽  
Carmen Romo Barrientos ◽  
Clara Maestre-Miquel ◽  
...  
Keyword(s):  
Room Temperature ◽  
Real Life ◽  
Health Sciences ◽  
Extreme Heat ◽  
Cross Sectional ◽  
La Mancha ◽  
Life Circumstance ◽  
Before And After ◽  
Different Temperatures ◽  
Academic Year

Teaching and training cardiopulmonary resuscitation (CPR) through simulation is a priority in Health Sciences degrees. Although CPR is taught as a simulation, it can still be stressful for the trainees since it resembles a real-life circumstance. The aim of this study was to assess the physiological effects and anxiety levels of health sciences undergraduates when faced with CPR process in different temperatures (room temperature, extremely cold, or extremely warm). This was a descriptive cross-sectional before–after study conducted during the 2018/2019 academic year with 59 students registered in the Faculty of Health Sciences of the Castilla-La Mancha University (UCLM). State Trait Anxiety Inventory (STAI) questionnaires were distributed among the students before and after the CPR simulation. We found greater level of situational anxiety in undergraduates faced with extreme adverse temperature scenarios (extreme heat and cold), especially in conditions of extreme heat compared to controlled environment (at room temperature). We discovered differences regarding sex, in which men scored 6.4 ± 5.55 points (STAI after CPR score) and women scored 10.4 ± 7.89 points (STAI after CPR score). Furthermore, there was less lactate in blood, before and during the event in individuals with anxiety. In addition, beginning in Minute 7, we observed a remarkable decrease (but not significant) in the performance of rescuers with anxiety. Programs targeted at promoting coping mechanisms to reduce anxiety before a critical clinic situation should be implemented in academic training.

Mechanical Nanocrystallization Surface Treatment on the Reheated 400MPa Ultrafine Grained Steel

2009 ◽  
Vol 79-82 ◽  
pp. 377-380
Author(s):  
Hong Yun Zhao ◽  
Guo Dong Wang ◽  
Chun Hua Xu ◽  
Feng Yuan Shu
Keyword(s):  
Mechanical Properties ◽  
Surface Treatment ◽  
Room Temperature ◽  
Performance Testing ◽  
Surface Form ◽  
Test Results ◽  
Ultrafine Grained ◽  
Before And After ◽  
Different Temperatures ◽  
Ultrafine Grained Steel

After reheated at different temperatures for 5 minutes, the 400MPa Ultrafine Grained Steel specimens were air-cooled to room temperature, and then carried out the mechanical nanocrystallization surface treatment and structure performance testing. On the basis of comparing the test results on the specimens before and after the mechanical nanocrystallization surface treatment, the process of mechanical nanocrystallization was analyzed briefly. The results show that: as the reheating temperature rising, the trend of grain size growing increases markedly, and the mechanical properties also drop down to different degrees; when the reheating temperature is around 800°C, because of the pearlite spheroidized significantly, its mechanical properties drop the most seriously; after the mechanical nanocrystallization surface treatment, not only its surface form a layer of fine nano-layer (about 100 nm) structure, but also its mechanical properties rise obviously, and the yield strength is over 450MPa.

Effect of Forging Temperature on Microstructure and Tensile Properties in Fe3Al-Based Alloy

1994 ◽  
Vol 364 ◽  
Author(s):  
Y. Yang ◽  
W. Yan ◽  
J. N. Liu ◽  
S. Hanada
Keyword(s):  
Plastic Deformation ◽  
Low Temperature ◽  
Yield Strength ◽  
Grain Boundaries ◽  
Tensile Properties ◽  
Room Temperature ◽  
Annealing Treatment ◽  
Different Temperatures ◽  
Local Plastic Deformation ◽  
Strength And Ductility

AbstractForging processes at two different temperatures are performed to examine the relation between the microstructure and room temperature tensile properties in a Ce doped Fe3Al-based alloy. Results show that the microstructure and the ductility are sensitive to the forging temperature before annealing treatment. Higher yield strength and ductility can be obtained through forging at a relatively low temperature of 750°C followed by annealing at 800°C and 500°C. It is suggested that the formation of non-equilibrium grain boundaries and banded subgrains within carbide-free areas along grain boundaries enhances the local plastic deformation and results in the improvement of ductility. During the initial deformation at room temperature <111> slip is predominant for both microstructures.

Evolution of photoluminescence from Si nanocrystals embedded in a SiO2 matrix prepared by reactive pulsed laser deposition

2009 ◽  
Vol 24 (7) ◽  
pp. 2259-2267 ◽  
Author(s):  
Fang Fang ◽  
Wei Zhang ◽  
Jian Sun ◽  
Ning Xu ◽  
Jiang Zhu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Annealing Temperature ◽  
Pulsed Laser ◽  
Average Diameter ◽  
Peak Position ◽  
Nitrogen Atmosphere ◽  
Film Deposition ◽  
Structural Variations ◽  
Si Nanocrystals ◽  
Before And After

Photoluminescence (PL) properties of SiOx thin films deposited by pulsed laser ablation of Si in a reactive oxygen ambient and annealed in a nitrogen atmosphere were studied at room temperature. Raman spectroscopy, Fourier transform infrared spectroscopy, and optical transmission measurements were used to characterize the deposited films before and after annealing and complement the PL studies. Strong PL due to quantum confinement was observed at room temperature from Si nanocrystals with an average diameter of approximately 5 nm at 325-nm light excitation. An apparent dependence of PL on the oxygen pressure for film deposition was observed. A detailed analysis of the effects of the annealing temperature revealed a significant PL evolution in luminescence intensity, spectrum profile, peak position, and spectrum range with the annealing temperature ranging from 300 to 1200 °C. Structural variations induced by thermal annealing of the films deposited at different oxygen pressures were also discussed on the basis of their correlation with the PL evolution.

Effects of vacuum annealing treatment on microstructures and residual stress of AlSi10Mg parts produced by selective laser melting process

2016 ◽  
Vol 30 (19) ◽  
pp. 1650255 ◽  
Author(s):  
Tian Chen ◽  
Linzhi Wang ◽  
Sheng Tan
Keyword(s):  
Residual Stress ◽  
Tensile Strength ◽  
Selective Laser Melting ◽  
Vacuum Annealing ◽  
Annealing Treatment ◽  
Melting Process ◽  
Second Phase ◽  
Laser Melting ◽  
Heat Treated ◽  
Before And After

Selective laser melting (SLM)-fabricated AlSi10Mg parts were heat-treated under vacuum to eliminate the residual stress. Microstructure evolutions and tensile properties of the SLM-fabricated parts before and after vacuum annealing treatment were studied. The results show that the crystalline structure of SLM-fabricated AlSi10Mg part was not modified after the vacuum annealing treatment. Additionally, the grain refinement had occurred after the vacuum annealing treatment. Moreover, with increasing of the vacuum annealing time, the second phase increased and transformed to spheroidization and coarsening. The SLM-produced parts after vacuum annealing at 300[Formula: see text]C for 2 h had the maximum ultimate tensile strength (UTS), yield strength (YS) and elongation, while the elastic modulus decreased significantly. In addition, the tensile residual stress was found in the as-fabricated AlSi10Mg samples by the microindentation method.

Characterization of Cold-Sprayed FeAl/WC Nanocomposite Coating

2013 ◽  
Vol 423-426 ◽  
pp. 63-66
Author(s):  
Hong Tao Wang ◽  
Ruo Yu Wang ◽  
Xiao Chen ◽  
Xiao Bo Bai ◽  
Zeng Xiang Dong ◽  
...  
Keyword(s):  
Grain Size ◽  
Lamellar Structure ◽  
Annealing Temperature ◽  
Annealing Treatment ◽  
Cold Spraying ◽  
Nanocomposite Coating ◽  
Mechanically Alloyed ◽  
Dense Microstructure ◽  
Before And After

A FeAl/WC nanocomposite coating was produced by cold spraying of mechanically alloyed Fe/Al/WC composite powder assisted with annealing treatment. The microstructure and grain size of FeAl/WC nanocomposite coating before and after annealing treatment were characterized. The results indicated that as-sprayed Fe (Al)/WC nanocomposite coating presented a dense microstructure with lamellar structure. The phase transformation from Fe (Al) solid solution to FeAl intermetallics within as-sprayed nanocomposite coating occurred when annealed at 550°C for 25 h. The annealed nanocomposite coating was composed of nanograins of size ranging from 50-100 nm and the grain size of FeAl increased with increasing the annealing time. Moreover, the effect of annealing temperature on the microstructure of the FeAl/WC nanocomposite coating was investigated.

Wandering of Crosslinks in Rubber at High Temperature

1959 ◽  
Vol 32 (3) ◽  
pp. 696-700
Author(s):  
M. J. Voorn ◽  
J. J. Hermans
Keyword(s):  
Stress Relaxation ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Crosslinking Density ◽  
Heat Treated Sample ◽  
Equilibrium Degree ◽  
Heat Treated ◽  
Before And After ◽  
Final Stress ◽  
Different Temperatures

Abstract There are strong reasons to believe that on heating a crosslinked rubber crosslinks are broken and new ones formed. This has been established by the well-known work on stress relaxation of Tobolsky and his school, and others. In the following we will discuss some experiments which give further support to these views, both of a qualitative and quantitative nature. In the first place, we carried out a few preliminary experiments on stress relaxation at elevated temperatures. This stress relaxation may be due to either or both of two effects : (a) a displacement of the crosslinks, (b) a change in the number of crosslinks per unit of volume (crosslinking density p). A measure of ρ can be obtained from the equilibrium degree of swelling at room temperature, and this gives us a means of comparing changes of ρ in a stretched sample with those occurring in the unstretched state. To this end commercial rubber strips were heated in the stretched state in the absence of oxygen at three different temperatures (80, 106, 122° C) for times varying from 2 to 72 hours. The degree of stretch, i.e., the length of the stretched rubber divided by the original length was α=1 (unstretched) in one series, and α=3 in a second series. The initial stress τ0 (for α=3) and the final stress τ at the end of the heating period were read from the stress-strain diagrams, taking into account that for the heat-treated strips there was a permanent set. In other words, τ is the stress needed to give the heat-treated sample at room temperature a length 3 times the length of the original untreated sample; the ratio τ/τ0 is therefore essentially the ratio between the moduli of elasticity. The cross-linking densities ρ0 and ρ before and after heating were derived from swelling experiments (for details see the sections on swelling).

Processing and Properties of FeAl Sheets Obtained by Roll Compaction and Sintering of Water Atomized Powder

1998 ◽  
Vol 552 ◽  
Author(s):  
S. C. Deevi ◽  
M. R. Hajaligol ◽  
V. K. Sikka ◽  
J. McKernon ◽  
C. R. Scorey
Keyword(s):  
Room Temperature ◽  
Annealing Temperature ◽  
Vacuum Annealing ◽  
Reduction Process ◽  
Vacuum Furnace ◽  
Al Content ◽  
Metallurgical Processing ◽  
Fine Microstructure ◽  
Roll Compaction ◽  
Edge Cracking

ABSTRACTThe low ductilities of FeAl alloys led us to explore powder metallurgical processing technology to obtain sheets of 0.2mm thickness as opposed to manufacturing processes based on hot rolling of cast FeAl alloys. In our approach, water atomized FeAl powders were roll compacted to 0.66mm with a polymeric binder using two counter rotating rolls to a green density of 3.1 g/cc. Roll compacted green sheets were then de-bindered in nitrogen in the temperature range of 300 to 600°C for several hours prior to sintering the sheets in vacuum. Sintered sheets were rolled down from 0.66 to 0.20 mm in three different stages resulting in a total reduction of 69% Vacuum annealing of the sheets was carried out between each stage of the reduction process to eliminate edge cracking associated with the work hardening of the FeAl. The properties of the FeAl sheets depend on the Al content, annealing temperature and time in a vacuum furnace. The fine microstructure of FeAl sheets led to tensile elongations of 4 to 6%. The sheets are formable at room temperature, and possess excellent mechanical properties both at room and high temperatures.

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