Mechanical and Microstructural Analyses of Three Layered Cu-Ni-Zn/Cu-Zr/Cu-Ni-Zn Clad Material Processed by High Pressure Torsioning (HPT)

2012 ◽  
Vol 557-559 ◽  
pp. 1161-1165
Author(s):  
Ki Hwan Oh ◽  
Hob Yung Kim ◽  
Sun Ig Hong
Keyword(s):  
Heat Treatment ◽  
High Pressure ◽  
Intermetallic Compounds ◽  
Interfacial Reaction ◽  
Room Temperature ◽  
Mechanical Reliability ◽  
Final Fracture ◽  
Heat Treated

Cu-Ni-Zn/Cu-Zr/Cu-Ni-Zn three layered clad plates were prepared by high pressure torsioning (HPT) at room temperature and theirmicrostructural and mechanical analyses wereperformed. No intermetallic compounds were observed at Cu-Zr/Cu-Ni-Zn interfaces in the as-HPTed and heat-treated Cu/Ni-Zn/Cu-Zr/Cu-Ni-Zn clad plates. The strength of as-HPTed clad plate reached up to 610 MPa with the ductility of 14%. After heat treatment at 500oC, Cu-Ni-Zn/Cu-Zr/Cu-Ni-Zn clad plate exhibited the strength up to 490 MPa and the ductility of 28 %. The clad plate fractured all together at the same time without discontinuous drop of the stress until final fracture. The excellent mechanical reliability and the good interfacialbonding strength can be attributed to the absence of detrimental interfacial reaction compounds between Cu-Ni-Zn and Cu-Zr.

Mechanical Properties and Microstructure of Cu-Ni-Zn/Cu-Cr/Cu-Ni-Zn Clad Plate Processed by High Pressure Torsioning (HPT)

2013 ◽  
Vol 683 ◽  
pp. 318-321
Author(s):  
Hob Yung Kim ◽  
Jong Su Ha ◽  
Ki Hwan Oh ◽  
Sun Ig Hong
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Composite Plate ◽  
Room Temperature ◽  
Composite Plates ◽  
Layered Composite ◽  
Mechanical Reliability ◽  
Final Fracture ◽  
Heat Treated ◽  
Interfacial Bonding Strength

Cu-1 wt. % Cr was clad between Cu-Ni-Zn plates to form 3-layered composite by high pressure torsioning (HPT) at room temperature and theirmicrostructure and mechanical propertieswereexamined. No intermetallic compounds were observed at the interfaces in the as-HPTed and heat-treated 3-layered composite plates. The strength of as-HPTed composite plate reached up to 650 MPa with the ductility of 7 %. After heat treatment at 500oC, Cu-Ni-Zn/Cu-Cr/Cu-Ni-Zn clad plate exhibited the strength up to 420 MPa and the ductility of 32 %. The clad plate fractured all together at the same time without discontinuous drop of the stress until final fracture. The excellent mechanical reliability and the good interfacial bonding strength can be attributed to the absence of detrimental interfacial reaction compounds between Cu-Ni-Zn and Cu-Cr.

Microstructure and Mechanical Propertiesof Ti/Cu-Cr/S20C and Ti/Cu-Ag/S20C Clad Composites

2013 ◽  
Vol 376 ◽  
pp. 153-157 ◽  
Author(s):  
Jong Su Ha ◽  
Sun Ig Hong
Keyword(s):  
Heat Treatment ◽  
High Pressure ◽  
Strain Hardening ◽  
Intermetallic Compounds ◽  
Mechanical Performance ◽  
High Strength ◽  
Strengthening Mechanism ◽  
Reaction Products ◽  
Heat Treated ◽  
Strength And Ductility

In this study Cu-Ag or Cu-Cr layer was sandwiched by Ti and Fe plates and the three layers of Ti/Cu-8Ag/S20C were clad by High Pressure Torsioning(HPT). The effect of post-HPT heat treatment on the interfacial reaction products and the mechanical performance in Ti/Cu-Ag/S20C and Ti/Cu-Cr/S20C clad material were studied. Cu4Ti3 and Cu4Ti Intremetallic compound layers were observed at the Ti/Cu-Ag and Ti/Cu-Cr interfaces in the clad heat-treated at 500°C where as no intermetallic compounds were observed at the Cu-Ag/S20C and Cu-Cr/S20C interfaces. The strength of as-HPTed Ti/Cu-8Ag/S20C is much higher than that of Ti/Cu-1Cr/S20C. The strengthening mechanism of Cu-Ag deformed severely is the interface and strain hardening in which dislocations are deposited at the Cu/Ag interfaces and can contribute to the strengthening of the clad composite just after HPT processing, rendering the high strength just after processing. In both clad composites, the strength and ductility increased after heat treatment at 350°C, which are likely caused by the enhanced bonding at the interfaces.

Mechanical Behavior of 3-ply Cu-Ni-Zn/Cu-Cr/Cu-Ni-Zn Composite Plate Processed by Roll Bonding

2013 ◽  
Vol 813 ◽  
pp. 43-46
Author(s):  
Hob Yung Kim ◽  
Jae Sook Song ◽  
Sun Ig Hong
Keyword(s):  
Heat Treatment ◽  
Composite Plate ◽  
Strain Curve ◽  
Composite Plates ◽  
Aging Condition ◽  
Stress Strain Curve ◽  
Roll Bonding ◽  
Final Fracture ◽  
Heat Treated ◽  
Peak Aging

3-ply Cu-Ni-Zn/Cu-Cr/Cu-Ni-Zn clad composite plates were prepared by roll bonding at 823K and their properties were characterized. No intermetallic compounds were observed at Cu-Ni-Zn/Cu-Cr interfaces in the as-rolled and heat-treated Cu/Ni-Zn/Cu-Cr/Cu-Ni-Zn clad plates. The strength of as-rolled clad plate reached up to 420MPa with the ductility of 13%. After heat treatment at 723K for 1.5 hours, the strength of Cu-Ni-Zn/Cu-Cr/Cu-Ni-Zn clad composite plate dropped to 340 MPa and the ductility increased to 20%. With annealing at 723K, there is no drastic drop of the stress before final fracture, meaning three plates were bonded together until the last part of the stress-strain curve. The peak of the conductivity (>70% of IACS) was attained after aging for 1.5 hrs, compatible with the typical peak aging condition of Cu-Cr alloy.

Enhancement of Long-Wavelength Photoluminescence Due to Heat-Treatment in Si-Doped GaAs

1992 ◽  
Vol 262 ◽  
Author(s):  
M. Suezawa ◽  
A. Kasuya ◽  
Y. Nishina ◽  
K. Sumino
Keyword(s):  
Heat Treatment ◽  
Radiative Recombination ◽  
Room Temperature ◽  
Excitation Spectra ◽  
Long Wavelength ◽  
Heat Treated ◽  
Intense Luminescence ◽  
Si Doped

ABSTRACTHighly officient radiative recombination even at room temperature was found at a wavelength of about 1.3 μm in heat-treated Si-doped GaAs. The range of Si concentrations and the condition of heat-treatment to yield this intense luminescence were determined. Excitation spectra of the PL lines suggest that such PL lines are related to pairs of Si-donor and Si- acceptor and such pairs combined with gallium vacancies.

The Nature of Intermetallic Compounds and its Effect on Mechanical Properties of Cu/Al/Cu Clad Metals

2014 ◽  
Vol 951 ◽  
pp. 87-91 ◽  
Author(s):  
Won Nyeon Kim ◽  
Sun Ig Hong
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Intermetallic Compounds ◽  
Interfacial Reaction ◽  
Reaction Layer ◽  
Drastic Decrease ◽  
Interfacial Cracks ◽  
Clad Metals ◽  
Reaction Compound ◽  
Intermetallic Layers

The mechanical properties and microstructure of layered Cu/Al/Cu composites was investigated after annealing at various temperatures. The nature of intermetallic compounds in roll-bonded Cu/Al/Cu clad metals after heat treatment was investigated using SEM, XRD and EBSD.in the temperature range 200~500oC. In the roll-bonded 3-ply Cu/Al/Cu clad metal, no visible interfacial reaction compound and defects were observed at the interfaces. The reaction layer was observed grow rapidly at the Cu/Al interface after annealing at and above 400oC, which deteriorated the ductility of clad metals. Intermetallic reaction layers of Cu/Al/Cu clad materials annealed at 500oC for 3, 5, 10hours was found to consist of three layers, CuAl2, CuAl and Cu9Al4. EBSD analyses revealed that intermetallic layers are polycrystalline. The drastic decrease of stress and elongation in Cu/Al/Cu clad composite annealed at 500oC can be linked to the interfacial cracks between Al and Cu layer.

Effect of Different Initial Lamellar Plate Thicknesses on Grain Refinement and Superplastic Behaviour in HPT-Processed Ti-6Al-4V Alloy

2018 ◽  
Vol 385 ◽  
pp. 182-188
Author(s):  
Yi Huang ◽  
Jessica Muzy ◽  
Piotr Bazarnik ◽  
Małgorzata Lewandowska ◽  
Terence G. Langdon
Keyword(s):  
High Pressure ◽  
Lamellar Structure ◽  
Room Temperature ◽  
High Pressure Torsion ◽  
Phase Transformation Temperature ◽  
Air Cooling ◽  
Microstructure Development ◽  
Superplastic Behaviour ◽  
Β Phase ◽  
Heat Treated

Ti-6Al-4V alloy was heated to above the β phase transformation temperature with two different cooling speeds: air cooling and furnace cooling, in order to generate a full thin lamellar structure and a fully coarse lamellar structure, respectively. Then the alloy in two heat-treated conditions was processed at room temperature up to 10 turns by high-pressure torsion (HPT) processing. Investigations were carried out to study the effect of the different initial lamellar plate thicknesses on the microstructure development during HPT processing, and the corresponding superplastic behaviour at the selected low testing temperatures of 773 - 923 K.

scholarly journals Влияние термообработки на электрические характеристики полуизолирующих слоев, полученных с помощью облучения n-SiC высокоэнергетическими ионами аргона

2018 ◽  
Vol 44 (6) ◽  
pp. 11 ◽  
Author(s):  
П.А. Иванов ◽  
А.С. Потапов ◽  
М.Ф. Кудояров ◽  
М.А. Козловский ◽  
Т.П. Самсонова
Keyword(s):  
Heat Treatment ◽  
Silicon Carbide ◽  
Room Temperature ◽  
High Energy ◽  
Room Temperature Resistivity ◽  
Electrical Characteristics ◽  
Near Surface ◽  
Heat Treated ◽  
Argon Ions ◽  
Temperature Resistivity

AbstractIrradiation of crystalline n -type silicon carbide ( n -SiC) with high-energy (53-MeV) argon ions was used to create near-surface semi-insulating ( i -SiC) layers. The influence of subsequent heat treatment on the electrical characteristics of i -SiC layers has been studied. The most high-ohmic ion-irradiated i -SiC layers with room-temperature resistivity of no less than 1.6 × 10^13 Ω cm were obtained upon the heat treatment at 600°C, whereas the resistivity of such layers heat-treated at 230°C was about 5 × 10^7 Ω cm.

scholarly journals Hydrogen Detection with SAW Polymer/Quantum Dots Sensitive Films

Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4481 ◽  
Author(s):  
Izabela Constantinoiu ◽  
Cristian Viespe
Keyword(s):  
Heat Treatment ◽  
Quantum Dots ◽  
Room Temperature ◽  
Limit Of Detection ◽  
Composite Films ◽  
High Specific Surface Area ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Heat Treated ◽  
Gas Molecules

Regarding the use of hydrogen as a fuel, it is necessary to measure its concentration in air at room temperature. In this paper, sensitive composite films have been developed for surface acoustic wave (SAW) sensors, using quantum dots (QDs) and polymers. Si/SiO2 QDs were used due to having a high specific surface area, which considerably improves the sensitivity of the sensors compared to those that only have a polymer. Si/SiO2 QDs were obtained by laser ablation and analyzed by X-ray diffraction and transmission electron microscopy (TEM). Two types of polymers were used: polydimethylsiloxane (PDMS) and polymethylmethacrylate (PMMA). Polymer and polymer with QDs compositions were deposited on the sensor substrate by drop casting. A heat treatment was performed on the films at 80 °C with a thermal dwell of two hours. The sensors obtained were tested at different hydrogen concentrations at room temperature. A limit of detection (LOD) of 452 ppm was obtained by the sensor with PDMS and Si/SiO2 QDs, which was heat treated. The results demonstrated the potential of using QDs to improve the sensitivity of the SAW sensors and to achieve a heat treatment that increases its adsorption capacity of the gas molecules.

Platinum-TiO2 (Rutile) Substrate Interaction During Cyclic Oxidation-Reduction Heat-Treatment

1981 ◽  
Vol 39 ◽  
pp. 72-73
Author(s):  
S. Shinozaki ◽  
W. T. Donlon ◽  
A. H. Meitzler
Keyword(s):  
Heat Treatment ◽  
Room Temperature ◽  
Treatment Procedure ◽  
Substrate Interaction ◽  
Reducing Atmosphere ◽  
Oxidation Reduction ◽  
Heat Treated ◽  
Pt Electrodes ◽  
The Matrix ◽  
Tio2 Rutile

When polycrystalline TiO2 (rutile) pellets (∼1mm in thickness and ∼3 mm in diameter), dispersed with Pt particles to act as a catalyst, were heat-treated under certain conditions involving an applied electric field, new unusual microstructures were formed. The heat-treatment procedure was, as follows: 1) apply 1 volt dc field between two Pt electrodes inbedded into the pellet, 2) heat the sample to 750°C and begin cycling the sample between oxydizing (4% O2 in N2) and reducing (2% CO in N2) atmospheres at a rate of several cycles per hour, 3) lower the temperature to 600°C while continually cycling (200 cycle), and, 4) cool the sample to room temperature under the reducing atmosphere (1). The pellet was ion milled to a proper electron transparency and examined by means of a Siemens EM102 and a Philips EM400 TEM-STEM microscope.Some TiO2 grains in this sample exhibited no resolvable defect structure, except that the matrix appeared to be strained due to small defects (Fig. la).

Sign in / Sign up

Export Citation Format

Share Document