Influence of Ru and Cr on the Heat-Treated Microstructure of Ni-Based Superalloys

2007 ◽  
Vol 546-549 ◽  
pp. 1207-1210 ◽  
Author(s):  
W.B. Wang ◽  
Qiang Feng ◽  
L.J. Carroll ◽  
Y.L. Wang ◽  
Guo Liang Chen ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Lattice Misfit ◽  
Microstructural Stability ◽  
Scanning Calorimetry ◽  
Heat Treated ◽  
Tcp Phases ◽  
Microstructural Instability ◽  
Cr Addition ◽  
Neutral Effect ◽  
Liquidus Temperatures

The effects of ruthenium and chromium contents have been investigated on phase transformation temperatures and the morphology of γ’ precipitates as well as microstructural stability in high refractory Ni-base superalloys. The solidus and liquidus temperatures were determined by differential scanning calorimetry (DSC), suggesting that the addition of Cr resulted in a decrease in solidus/liquidus temperatures while the Ru addition (3.5 at.%) had the neutral effect. The morphology of γ’ precipitates in the heat-treated microstructure was changed under the influence of the Cr and Ru additions, suggesting that Ru and Cr contents affected the γ−γ’ lattice misfit through changes in the associated partitioning to the constituent phases. The microstructural instability has been investigated at 1000 oC. High levels of Cr addition (8 at.%) strongly promoted the formation of TCP phases, while Ru improved the microstructural stability to some extent.

The Solubility of Gd2O3 in K Cl-GdCl3 Melts

2020 ◽  
Vol 989 ◽  
pp. 91-96
Author(s):  
Irina D. Zakir'yanova ◽  
Elena V. Nikolaeva ◽  
Iraida V. Korzun
Keyword(s):  
Differential Scanning Calorimetry ◽  
Rare Earth ◽  
Molten Salts ◽  
Gadolinium Oxide ◽  
Rare Earth Oxides ◽  
Cooling Curves ◽  
Scanning Calorimetry ◽  
Liquidus Temperatures

The differential scanning calorimetry and the method of cooling curves are used to obtain data on liquidus temperatures of oxide-chloride systems Gd2O3 – K Cl - GdCl3. The solubility of gadolinium oxide in K Cl - GdCl3 melts has been studied. This information can be used for a developing process of the reduction of solid rare-earth oxides into their metals in molten salts.

scholarly journals THERMAL ANALYSIS OF FOOD PRODUCTS USING DIFFERENTIAL SCANNING CALORIMETRY (DSC)

2019 ◽  
Vol 10 (2) ◽  
Author(s):  
Radoslav Grujić ◽  
Danica Savanović
Keyword(s):  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
Food Products ◽  
Freezing And Thawing ◽  
Frozen Foods ◽  
Scanning Calorimetry ◽  
Scanning Rate ◽  
Heat Treated ◽  
Treated Apple ◽  
Freezing Storage

Intensity of changes during the freezing storage of frozen foods, depends on several factors. Changes of foods during freezing and thawing can be rapidly determined by scanning calorimetry (DSC). The aim of this study was to test the influence of scanning rate on the thermal properties of previously heat-treated food products (boiled apple), using the differential scanning calorimetry method. By increasing the scanning rate, significant changes (p0.05) Tcon from -14,20 °C (rate 5 °C/min) to -15.57 °C (rate 15 °C/min) and Tcend (from -17.53 °C to -22.90 °C) were determined, and ΔTc increased from 3.33 °C to 7.33 °C. At the same time, the width of the melting temperature interval (ΔTm) increased from 7.80 °C to 12.87 °C. The glass transition temperature (Tgmid) ranged from -7.15 °C (rate 5 °C/min) to -6.60 °C (rate 15 °C/min). Based on the obtained results, it was found that the scanning rate during the DSC determination statistically significantly (p0.05) influenced the measured values of the thermal properties of the tested heat-treated apple samples.

A New Method for Synthesis of FeMnO3 Ceramics and its Phase Transformation

2015 ◽  
Vol 37 ◽  
pp. 122-131 ◽  
Author(s):  
Zhi Jie Li ◽  
Shi Fa Wang ◽  
Bo Li ◽  
Xia Xiang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Phase Transformation ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Heat Treated ◽  
Average Coefficient ◽  
Modified Polyacrylamide ◽  
Scanning Electron

FeMnO3 powders were synthesized through a modified polyacrylamide gel route. The gel and the heat treated final powders have been characterized by X-ray diffractometry (XRD), differential scanning calorimetry and thermogravimetric analysis (TG/DSC) and field-emission scanning electron microscopy (SEM). Phase transformation sequence of dry gel during heating is (Mn+3,Fe+3)2O3→(α-Mn2O3)·(α-Fe2O3)→FeMnO3. The thermal expansion properties of as-prepared sample were determined. From 100 to 700 °C, the average coefficient of expansion is 9.0139×10-6 /K. The experimental results demonstrates that the FeMnO3 sample exhibit a ferromagnetic transitions with TN ≈ 40 K.

Effects of Re on Microstructure of Ni3Al-Based Single Crystal Superalloys

2014 ◽  
Vol 788 ◽  
pp. 498-503 ◽  
Author(s):  
Jing Yang Chen ◽  
Ming Xue ◽  
Xin Tang ◽  
La Mei Cao
Keyword(s):  
Single Crystal ◽  
Volume Fraction ◽  
Lattice Misfit ◽  
Alloying Elements ◽  
Microstructural Stability ◽  
Segregation Ratios ◽  
Kinetics Of ◽  
Liquidus Temperatures

The effects of Re on solidus/liquidus temperatures, solidification segregation characteristics of alloying elements, γ′ morphology and volume fraction as well as microstructural stability at 1150 °C have been investigated in two experimental Ni3Al-based single crystal superalloys with and without Re (1.0 wt%) addition. The results indicated that Re addition increased the solidus/liquidus temperatures. The segregation characteristics of Ni3Al-based single crystal superalloys were similar with Ni-based single crystal superalloys, and the solidification segregation ratios of W and Mo increased slightly due to Re addition. Meanwhile, Re addition resulted in more negative lattice misfit, more cuboidal γ′ phase and higher γ′ volume fraction. The kinetics of γ′ coarsening and rafting at 1150 °C was lowered substantially compared with the addition of Re.

scholarly journals Evaluation of heat-treated wood swelling by differential scanning calorimetry in relation to chemical composition

Holzforschung ◽  
2005 ◽  
Vol 59 (1) ◽  
pp. 28-34 ◽  
Author(s):  
Vincent Repellin ◽  
René Guyonnet
Keyword(s):  
Heat Treatment ◽  
Differential Scanning Calorimetry ◽  
Beech Wood ◽  
Treated Wood ◽  
Volumetric Shrinkage ◽  
Scanning Calorimetry ◽  
Chemical Changes ◽  
Adsorption Sites ◽  
Heat Treated ◽  
Dsc Method

Abstract Retification is a heat treatment that decreases the swelling of wood and increases its resistance to fungal attack. In this study, differential scanning calorimetry (DSC) was applied in order to determine the fibre saturation point (FSP) of natural and retified wood. FSP values were used to determine the total swelling of natural and heat-treated wood. The DSC method was compared to the volumetric shrinkage approach. The influence of heat treatment temperature and duration on the swelling of wood was investigated. Relationships between chemical changes and the reduction of swelling were analysed thoroughly. The equivalence of the DSC method and the volumetric shrinkage method is shown. FSP in association with anhydrous density is a good indicator for the evaluation of the overall swelling of heat-treated wood. Reduction of wood swelling with increasing temperature and duration of thermal treatment is often attributed to hemicellulose destruction. This study shows that the reduction of beech wood swelling cannot only be attributed to the disappearance of adsorption sites that goes with hemicellulose destruction. It is suggested that other phenomena such as structural modifications and chemical changes of lignin also play an important role.

Effect of tensile stress on the annealed structure of a metallic glass

1987 ◽  
Vol 2 (4) ◽  
pp. 461-470 ◽  
Author(s):  
P. T. Vianco ◽  
J. C. M. Li
Keyword(s):  
Heat Treatment ◽  
Differential Scanning Calorimetry ◽  
Glass Transition ◽  
Tensile Stress ◽  
Room Temperature ◽  
Exothermic Peak ◽  
Scanning Calorimetry ◽  
Disordered Structure ◽  
Heat Treated ◽  
Dsc Thermograms

The low-temperature (120°–245°C) structural relaxation of Metglas¯ 2826B (Ni49Fe29P14B6Si2) amorphous alloy was investigated for samples subjected to a tensile stress in the range of 20–400 MPa during annealing. The stress-annealed samples demonstrated a much smaller increase of microhardness than was observed in similarly annealed ribbons without a stress. Further heat treatment of the stress-annealed specimens, this time without the stress, was capable of increasing the microhardnesses of only some ribbons to values equal to those of samples similarly heat treated initially without a stress. An additional exothermic peak in the differential scanning calorimetry (DSC) thermograms of the stress-annealed specimens indicated the presence of a more disordered structure at room temperature, which was found to correlate with the lower microhardness values. Otherwise, those artifacts of the DSC thermograms that were characteristic of samples annealed without a stress were still present in the stress-annealed ribbons. No effect on the crystallization temperature was noted but the glass transition temperature was increased in the stress-annealed case with respect to values attained when the stress was absent during heat treatment. A reduction in the degree of embrittlement of those samples annealed with a tensile stress was a further indication of more disorder in the stress-annealed ribbons.

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