Laser-controlled precipitation of gold nanoparticles in silicate glasses

2003 ◽  
Vol 18 (9) ◽  
pp. 2097-2100 ◽  
Author(s):  
Xiongwei Jiang ◽  
Jianrong Qiu ◽  
Huidan Zeng ◽  
Congshan Zhu
Keyword(s):  
Heat Treatment ◽  
Gold Nanoparticles ◽  
Femtosecond Laser ◽  
Optical Switches ◽  
Sample Heat ◽  
Selective Precipitation ◽  
Heat Treated ◽  
All Optical ◽  
Potential Applications ◽  
Controlled Precipitation

We report on the observation of space-selective precipitation of gold nanoparticles in Au2O-doped silicate glass by a method of irradiation with an 800-nm femtosecond laser and further heat treatment. The irradiated region of the glass first became gray in color after irradiation with the femtosecond laser and then turned red after further heat treatment at around 520 °C, indicating that gold nanoparticles have precipitated in the irradiated region of the glass. A possible mechanism has been suggested that the Au+ ions in the region irradiated are reduced to Au0 atoms by the femtosecond laser, and then the Au0 atoms accumulate to form gold nanoparticles with the glass sample heat treated. The observed phenomenon should have potential applications in the fabrication of ultrafast all-optical switches.

Effect of Heat Treatment on the DC Conductivity and Activity Energy of Li2O-Fe2O3-P2O5 Glasses

2007 ◽  
Vol 336-338 ◽  
pp. 1827-1828 ◽  
Author(s):  
Ji Yong Pan ◽  
Jiang Hong Gong
Keyword(s):  
Heat Treatment ◽  
Electrical Properties ◽  
Heat Treating ◽  
Iron Phosphate ◽  
Phosphate Glasses ◽  
Sample Heat ◽  
Heat Treated ◽  
Maximum Conductivity ◽  
Iron Phosphate Glasses ◽  
Activity Energy

Iron phosphate glasses with composition of 20Li2O-32Fe2O3-48P2O5 (in mol%) was prepared by melting, crushing and heat-treating process and the electrical properties were examined. It was found that the sample heat-treated at a temperature close to the glass transition temperature exhibit the maximum conductivity and the lowest activation energy, implying that heat-treatment may play an important role in the electrical properties of the glasses.

scholarly journals Tunable Optical Bistability, Tristability and Multistability in Arrays of Graphene

2020 ◽  
Vol 10 (17) ◽  
pp. 5766
Author(s):  
Xiuju Zhao ◽  
Bin Xu ◽  
Xiangna Kong ◽  
Dong Zhong ◽  
Ming Fang ◽  
...  
Keyword(s):  
Optical Bistability ◽  
Chemical Potential ◽  
Incident Light ◽  
Logic Gates ◽  
Optical Switches ◽  
Optical Logic ◽  
Incident Intensity ◽  
Incident Wavelength ◽  
All Optical ◽  
Potential Applications

The optical bistability, tristability and multistability are explored in arrays of graphene. The arrays are periodically arranged spatially by single sheets of graphene. Optical bistability could be achieved with a strong enough incident intensity of light wave. The thresholds of optical bistability and the intervals between the upper and lower thresholds change with the surface conductivity of graphene and the incident wavelength. By increasing the intensity of incident light, tristability and multistability can be induced as well. Furthermore, the thresholds of bistability, tristability and multistability can be regulated via the chemical potential of graphene. This study may have potential applications in optical logic gates, all-optical switches and photomemory.

Wear Behavior of Plasma Processed LM6 Alloy

2020 ◽  
Vol 978 ◽  
pp. 140-144
Author(s):  
Jagadish Parida ◽  
Subash Chandra Mishra ◽  
Suresh Chandra Pattnaik
Keyword(s):  
Heat Treatment ◽  
Lamellar Structure ◽  
Wear Behavior ◽  
Treatment Temperature ◽  
Structure And Properties ◽  
Sample Heat ◽  
Plasma Technique ◽  
Heat Treated ◽  
Pin On Disc ◽  
Set Up

In the current work, wear behavior of plasma processed LM6 alloy is investigated. LM6 alloy was prepared by plasma technique. The samples were aged at 350°C & 450°C for 2 hours followed by water quenching. A comparative study of the metallographic structure and properties viz. hardness, density and wear of the non-heat and heat treated alloy samples were carried out. A very fine lamellar structure is observed in case of 450°C heat treated samples than that of sample heat treated at 350°C and non-heat treated samples. Highest hardness value of 68.11 VHN is observed with the sample heat treated at 450°C. Density is found to be the lowest in non-heat treated samples and it increases with increasing heat treatment temperature. Wear experiments were carried on a pin-on-disc set up (of Ducom make), varying applied loads (between 10-40Newton and varying sliding speed (from 0.94 m. s-1 to 2. 83m.s-1). Maximum wear resistance is observed with the specimen heat treated at 450°C.

SYNTHESIS OF NANOSIZE SILICON CARBIDE POWDER BY CARBOTHERMAL REDUCTION OF SiO2

2012 ◽  
Vol 05 ◽  
pp. 263-269 ◽  
Author(s):  
M. DEHGHANZADEH ◽  
A. ATAIE ◽  
S. HESHMATI-MANESH
Keyword(s):  
Heat Treatment ◽  
Silicon Carbide ◽  
Phase Composition ◽  
Crystalline Silicon ◽  
High Energy ◽  
Nano Particles ◽  
Process Conditions ◽  
Sample Heat ◽  
State Reduction ◽  
Heat Treated

A mixture of silicon carbide nano-particles and nano-whiskers has been synthesized through solid state reduction of silica by graphite employing high energy planetary ball milling for 25 h and subsequent heat treatment at 1300-1700°C in dynamic argon atmosphere. Effects of process conditions on the thermal behavior, phase composition and morphology of the samples were investigated using DTA/TGA, XRD and SEM, technique, respectively. DTA/TGA analysis shows that silicon carbide starts to form at ~ 1250°C. Analysis of the XRD patterns indicates that the phase composition of the sample heat treated at 1300°C for 2 h mainly consists of SiO 2 together with small amount of β- SiC . Nano-crystalline silicon carbide phase with a mean crystallite size of 38 nm was found to be dominate phase on heat treatment temperature at ~ 1500°C. Substantial SiO 2 was still remained in the above sample. SEM studies reveal that the sample heat treated at 1500°C for 2 h contains nano-particles and nano-whisker of β- SiC with a mean diameter of almost ~ 85 nm. The results obtained were also showed that the characteristics of the synthesized SiC particles strongly depend on the mechanical activation and heat treatment conditions.

Investigation of the Portevin-Le Chatelier Effect in AlMgSi-Tailored Heat Treated Blanks

2015 ◽  
Vol 639 ◽  
pp. 123-130 ◽  
Author(s):  
Alexander Kahrimanidis ◽  
Daniel Wortberg ◽  
Marion Merklein
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Critical Strain ◽  
Influence Factors ◽  
High Demand ◽  
Short Term ◽  
Heat Treated ◽  
Critical Strain Rate ◽  
Potential Applications ◽  
Chatelier Effect

The dissolution of co-clusters in AlMgSi-alloys by a short term heat treatment can be used to locally adjust the mechanical properties of a blank for a following forming operation. This approach is known as Tailored Heat Treated Blanks (THTB) and allows to significant enhance the forming limits of AlMgSi-alloys. However, the dissolution of co-clusters leads to the observation of the Portevin-Le Chatelier (PLC) effect during deformation. The results are stretcher strain marks at the surface which are a limitation for potential applications of THTB. In contrast to AlMg-alloys, a critical strain rate above which no PLC effect occurs is not observed for the investigated alloys. This paper investigates various influence factors on the occurrence of the PLC effect for different AlMgSi-alloys and presents an approach under which conditions THTB can be used in applications with high demand on surface quality.

scholarly journals HEAT TREATMENT EFFECT ON THE CREEP OF INDUSTRIAL COPPER WIRE

2016 ◽  
Vol 22 (3) ◽  
pp. 181 ◽  
Author(s):  
Salim Gareh ◽  
Zakaria Boumerzoug
Keyword(s):  
Heat Treatment ◽  
Creep Test ◽  
Copper Wire ◽  
Dislocation Creep ◽  
Creep Life ◽  
Creep Tests ◽  
Sample Heat ◽  
Heat Treated ◽  
Three Samples ◽  
Rupture Mechanism

<p class="Default">Creep behavior of copper wire, produced by wiredrawing process in ENICAB Biskra, has been investigated by creep tests at 340°C under the stress 98,108 and 118 MPa. In this investigation, three samples have been tested: copper drawn wire non heat treated, and heat treated at 600°C and 700°C. Microstructure after the creep test was observed by optical microscopy to understand the rupture mechanism. We have found that the sample heat treated at 600 °C had a longer creep life. We have also deduced that the dislocation creep was the creep deformation mechanism of the drawn copper. SEM observations of fractured surfaces after creep tests of drawn copper wire non heat treated and  treated 10 min at 600 ° C under stress of 118 MPa.</p>

Effect of a Complex Heat Treatment on the Structure of 300M Steel

1981 ◽  
Vol 39 ◽  
pp. 312-313
Author(s):  
R. Padmanabhan ◽  
W. E. Wood
Keyword(s):  
Heat Treatment ◽  
Metal Carbides ◽  
Austenite Grain Size ◽  
300M Steel ◽  
Heat Treated ◽  
Strain Fracture ◽  
Prior Austenite Grain Size ◽  
Short Time ◽  
Final Tempering ◽  
Similar Yield

Intermediate high temperature tempering prior to subsequent reaustenitization has been shown to double the plane strain fracture toughness as compared to conventionally heat treated UHSLA steels, at similar yield strength levels. The precipitation (during tempering) of metal carbides and their subsequent partial redissolution and refinement (during reaustenitization), in addition to the reduction in the prior austenite grain size during the cycling operation have all been suggested to contribute to the observed improvement in the mechanical properties. In this investigation, 300M steel was initially austenitized at 1143°K and then subjected to intermediate tempering at 923°K for 1 hr. before reaustenitizing at 1123°K for a short time and final tempering at 583°K. The changes in the microstructure responsible for the improvement in the properties have been studied and compared with conventionally heat treated steel. Fig. 1 shows interlath films of retained austenite produced during conventionally heat treatment.

“In vitro” and in Animal Model Studies on a Double Virus- Inactivated Factor VIII Concentrate

1995 ◽  
Vol 74 (03) ◽  
pp. 868-873 ◽  
Author(s):  
Silvana Arrighi ◽  
Roberta Rossi ◽  
Maria Giuseppina Borri ◽  
Vladimir Lesnikov ◽  
Marina Lesnikov ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Animal Model ◽  
Factor Viii ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Virus Inactivation ◽  
Enveloped Viruses ◽  
Model Studies ◽  
Heat Treated

SummaryTo improve the safety of plasma derived factor VIII (FVIII) concentrate, we introduced a final super heat treatment (100° C for 30 min) as additional virus inactivation step applied to a lyophilized, highly purified FVIII concentrate (100 IU/mg of proteins) already virus inactivated using the solvent/detergent (SID) method during the manufacturing process.The efficiency of the super heat treatment was demonstrated in inactivating two non-lipid enveloped viruses (Hepatitis A virus and Poliovirus 1). The loss of FVIII procoagulant activity during the super heat treatment was of about 15%, estimated both by clotting and chromogenic assays. No substantial changes were observed in physical, biochemical and immunological characteristics of the heat treated FVIII concentrate in comparison with those of the FVIII before heat treatment.

Vanadium Additions to a High-Cr White Iron and its Effects on the Abrasive Wear Behavior.

MRS Advances ◽  
2020 ◽  
Vol 5 (59-60) ◽  
pp. 3077-3089
Author(s):  
Alexeis Sánchez ◽  
Arnoldo Bedolla-Jacuinde ◽  
Francisco V. Guerra ◽  
I. Mejía
Keyword(s):  
Heat Treatment ◽  
Abrasive Wear ◽  
Volume Fraction ◽  
Wear Behavior ◽  
Wear Behaviour ◽  
White Iron ◽  
Heat Treated ◽  
Bulk Hardness ◽  
Abrasive Wear Behavior ◽  
Vanadium Carbides

AbstractFrom the present study, vanadium additions up to 6.4% were added to a 14%Cr-3%C white iron, and the effect on the microstructure, hardness and abrasive wear were analysed. The experimental irons were melted in an open induction furnace and cast into sand moulds to obtain bars of 18, 25, and 37 mm thickness. The alloys were characterized by optical and electronic microscopy, and X-ray diffraction. Bulk hardness was measured in the as-cast conditions and after a destabilization heat treatment at 900°C for 45 min. Abrasive wear resistance tests were undertaken for the different irons according to the ASTM G65 standard in both as-cast and heat-treated conditions under a load of 60 N for 1500 m. The results show that, vanadium additions caused a decrease in the carbon content in the alloy and that some carbon is also consumed by forming primary vanadium carbides; thus, decreasing the eutectic M7C3 carbide volume fraction (CVF) from 30% for the base iron to 20% for the iron with 6.4%V;but overall CVF content (M7C3 + VC) is constant at 30%. Wear behaviour was better for the heat-treated alloys and mainly for the 6.4%V iron. Such a behaviour is discussed in terms of the CVF, the amount of vanadium carbides, the amount of martensite/austenite in matrix and the amount of secondary carbides precipitated during the destabilization heat treatment.

AMPCO 940 and AMPCO-TRODE 940

Alloy Digest ◽  
1993 ◽  
Vol 42 (3) ◽  
Keyword(s):  
Copper Alloys ◽  
Heat Treating ◽  
Resistance Welding ◽  
Chromium Alloy ◽  
Heat Treated ◽  
Association Class ◽  
Potential Applications ◽  
Minimum Requirements ◽  
Nickel Silicon ◽  
Plastic Injection

Abstract AMPCO 940 is a precipitation-hardening copper-nickel-silicon-chromium alloy developed for resistance welding and other applications now using the 1% beryllium-copper alloys. The heat-treated alloy is capable of meeting the RWMA (Resistance Welder Manufacturers Association) Class 3 minimum requirements-95,000 psi tensile strength, 90 Rockwell B hardness and 45% IACS electrical conductivity. Potential applications include resistance welding tips, wheels and fixtures. A major use is in plastic injection molding. AMPCO-TRODE 940 is used for repair welding and overlays. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as casting, forming, heat treating, machining, and joining. Filing Code: CU-434. Producer or source: Ampco Metal Inc. Originally published as Ampcoloy 940, April 1982, revised March 1993.

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