The High Temperature Degradation of Cd-Zn and Pb-Cd Eutectic Alloys

1981 ◽  
Vol 12 ◽  
Author(s):  
R. H. van de Merwe ◽  
R. W. Smith
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Room Temperature ◽  
Isothermal Annealing ◽  
Growth Direction ◽  
Thermal Treatments ◽  
Thermal Gradients ◽  
Eutectic Alloys ◽  
Melting Temperatures ◽  
Thermal Stability Of

ABSTRACTVarious thermal treatments have been applied to Cd-Zn and Pb-Cd eutectic alloys in an attempt to better understand the thermal stability of eutectics close to their melting temperatures. Specimens of each system were grown at 40, 400 and 4000 mm/hr to obtain microstructures which were either lamellar, lamellar/cellular, or cellular. These specimens were thermally treated by either: (1) isothermal annealing at 0.95 Tm (up to 192 hrs), (2) thermal cycling between room temperature and 0.95 Tm (up to 64 cycles), (3) exposing to thermal gradients parallel to the growth direction and maintaining one end of the specimen at 0.95 Tm and the opposite end at room temperature (up to 48 hrs). It was found in all cases that some microstructural changes occurred but that the two alloy systems displayed marked differences in degradation sequence. An explanation and interpretation of these decay sequences is attempted. The mechanical properties of the variouslytreated alloy specimens were determined and are correlated with the observed microstructural features. The Cd-Zn specimens coarsened more rapidly than equivalent Pb-Cd specimens, as might be expected since the interphase boundary energies have been reported as 86 and 67 erg/cm2 respectively.

Influence of Temperature of Severe Plastic Deformation and Aging on Microstructure, Mechanical Properties and Electrical Conductivitiy of the Cu-Cr-Zr Alloy

2018 ◽  
Vol 385 ◽  
pp. 273-277
Author(s):  
Elena Sarkeeva ◽  
Marina M. Abramova ◽  
Igor V. Alexandrov
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Room Temperature ◽  
High Pressure Torsion ◽  
Influence Of Temperature ◽  
Annealed Copper ◽  
Thermal Stability Of ◽  
Zr Alloy

The article studies an influence of temperature of severe plastic deformation (SPD) and post-deformation heat treatment on microstructure, mechanical properties and thermal stability of the Cu-0.5Cr-0.2Zr alloy. The results demonstrate that strength is considerably increased to 900 MPa by high pressure torsion (HPT) at room temperature. Subsequent ageing at 450 °С during 1 hour leads to a decay of solid solution and an allocation of dispersion particles that further incrises strength to 900 MPa, restores electrical conductivity to 70% IACS (International annealed copper standard) and enhances thermal stability of the alloy. When deformation temperature is increased to 300°С, strength is 690 MPa that is lower than in the case of deformation at room temperature that is related to reversion process at deformation. Additional a aging does not lead to an increase of strength characteristics.

Thermal Stability of PECS-Compacted Cu-Composites

2012 ◽  
Vol 527 ◽  
pp. 113-118 ◽  
Author(s):  
Riina Ritasalo ◽  
Ulla Kanerva ◽  
Simo Pekka Hannula
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Room Temperature ◽  
Temperature Stability ◽  
Thermal And Mechanical Properties ◽  
High Temperature Stability ◽  
Composite Powders ◽  
High Quality ◽  
Pulsed Electric Current ◽  
Thermal Stability Of

In this paper pulsed electric current sintering (PECS) is applied for submicron-sized copper (sm-Cu) based composite-powders aiming to produce MMC’s with higher strength and better temperature stability than reference sm-Cu. Incorporation of cuprite (Cu2O), alumina (Al2O3), titaniumdiboride (TiB2) and nano- and submicronsized diamonds (ND’s and SMD’s) improved noticeably the room temperature mechanical properties and the high-temperature stability of copper the effects becoming more noticeable with smaller dispersion size and higher amount of reinforcement. The hardness increment was at highest, when using ND’s or Al2O3. E.g., the microhardness for the reference sm-Cu sample and Cu with 3 vol.% ND’s, 6 vol.% ND’s and 2.5 vol.% Al2O3 were 1.02, 1.43, 1.77 and 1.58 GPa, respectively. Similar trend was noted also in the case of thermal stability and CTE. The study shows that Cu-ND, Cu-SMD and Cu-Cu2O are suitable for use at moderate temperatures around 623 - 673 K, whereas Cu-Al2O3 and Cu-TiB2 are suitable above 1023 K. In conclusion, PECS is suitable method to produce high quality Cu-composites having superior thermal and mechanical properties compared to those of sm-Cu.

Thermal Stability of InGaAs Quantum Dots Under Large Temperature Transients

2004 ◽  
Vol 829 ◽  
Author(s):  
R. Rangarajan ◽  
V. C. Elarde ◽  
J. J. Coleman
Keyword(s):  
Thermal Stability ◽  
Quantum Dots ◽  
Thermal Cycle ◽  
Room Temperature ◽  
Large Temperature ◽  
Thermal Treatments ◽  
Force Microscopy ◽  
Remarkable Improvement ◽  
Atomic Force ◽  
Thermal Stability Of

ABSTRACTWe report here studies of the thermal stability of InGaAs quantum dots that have been subjected to various thermal treatments. Atomic force microscopy and photoluminescence spectroscopy are used to analyze the effects of the thermal treatments. In this paper we present data that demonstrates a remarkable improvement in the thermal stability of quantum dots that were rapidly cooled down to room temperature following the growth of a GaAs capping layer. The observed thermal behavior is attributed to metastable states formed during post growth thermal cycle.

scholarly journals Controlling the Thermal Stability of Kyanite-Based Refractory Geopolymers

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2903
Author(s):  
Juvenal Giogetti Nemaleu Deutou ◽  
Rodrigue Cyriaque Kaze ◽  
Elie Kamseu ◽  
Vincenzo M. Sglavo
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
High Strength ◽  
Treatment Temperature ◽  
Strength Development ◽  
Particle Sizes ◽  
Cold Setting ◽  
Thermal Stability Of ◽  
Geopolymer Composites ◽  
Refractory Composites

The present project investigated the thermal stability of cold-setting refractory composites under high-temperature cycles. The proposed route dealt with the feasibility of using fillers with different particle sizes and studying their influence on the thermo-mechanical properties of refractory geopolymer composites. The volumetric shrinkage was studied with respect to particle sizes of fillers (80, 200 and 500 µm), treatment temperature (1050–1250 °C) and amount of fillers (70–85 wt.%). The results, combined with thermal analysis, indicated the efficiency of refractory-based kyanite aggregates for enhancing thermo-mechanical properties. At low temperatures, larger amounts of kyanite aggregates promoted mechanical strength development. Flexural strengths of 45, 42 and 40 MPa were obtained for geopolymer samples, respectively, at 1200 °C, made with filler particles sieved at 80, 200 and 500 µm. In addition, a sintering temperature equal to 1200 °C appeared beneficial for the promotion of densification as well as bonding between kyanite aggregates and the matrix, contributing to the reinforcement of the refractory geopolymer composites without any sign of vitrification. From the obtained properties of thermal stability, good densification and high strength, kyanite aggregates are efficient and promising candidates for the production of environmentally friendly, castable refractory composites.

scholarly journals Effects of Substitution of Y with Yb and Ce on the Microstructures and Mechanical Properties of Mg88.5Zn5Y6.5

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 31
Author(s):  
Hongxin Liao ◽  
Taekyung Lee ◽  
Jiangfeng Song ◽  
Jonghyun Kim ◽  
Fusheng Pan
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Creep Resistance ◽  
Room Temperature ◽  
High Thermal Stability ◽  
Long Period ◽  
Microstructures And Mechanical Properties

The microstructures and mechanical properties of the Mg88.5Zn5Y6.5-XREX (RE = Yb and Ce, X = 0, 1.5, 3.0, and 4.5) (wt.%) alloys were investigated in the present study. Mg88.5Zn5Y6.5 is composed of three phases, namely, α-Mg, long-period stacking ordered (LPSO) phases, and intermetallic compounds. The content of the LPSO phases decreased with the addition of Ce and Yb, and no LPSO phases were detected in Mg88.5Zn5Y2.0Yb4.5. The alloys containing the LPSO phases possessed a stratified microstructure and exhibited excellent mechanical properties. Mg88.5Zn5Y5.0Ce1.5 exhibited the highest creep resistance and mechanical strength at both room temperature and 200 °C, owing to its suitable microstructure and high thermal stability. The yield strength of Mg88.5Zn5Y5.0Ce1.5 at room temperature was 358 MPa. The ultimate tensile strength of Mg88.5Zn5Y5.0Ce1.5 at room temperature and 200 °C was 453 MPa and 360 MPa, respectively.

Thermal stability of Ti–45 wt % Nb alloy at isothermal annealing

2020 ◽  
Author(s):  
I. A. Glukhov ◽  
A. Yu. Eroshenko ◽  
M. A. Khimich ◽  
A. M. Mairambekova ◽  
A. I. Tolmachev ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Isothermal Annealing ◽  
Thermal Stability Of
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