Effect of Ta on the Solidification Behavior of Ni3Al-Base Single-Crystal Superalloys

2014 ◽  
Vol 788 ◽  
pp. 426-432 ◽  
Author(s):  
Tian Tian Zheng ◽  
Shu Suo Li ◽  
Yan Ling Pei ◽  
Cheng Ai ◽  
Sheng Kai Gong
Keyword(s):  
Differential Scanning Calorimetry ◽  
Single Crystal ◽  
Early Stage ◽  
Solidification Rate ◽  
Solidification Process ◽  
Primary Phase ◽  
Isothermal Quenching ◽  
Solidification Behavior ◽  
Scanning Calorimetry

Two kinds of Ni3Al-base SC superalloys, including IC31A (3wt.%Ta) and IC31B (6wt.%Ta) were investigated in the present study by using the differential scanning calorimetry (DSC) and isothermal quenching technology. The results showed that the larger amount of blocky γ′ phases existed in IC31B than that in IC31A. In the solidification process, the primary phase in IC31B was γ′ phases while in alloy IC31A the primary phase was γ phases. Besides, the solidification rate of IC31B in the early stage was lower than that in IC31A.

New crystal structures in the realm of 5,5′-azotetrazolates

2015 ◽  
Vol 70 (2) ◽  
pp. 125-134 ◽  
Author(s):  
Martin Lampl ◽  
Gerhard Laus ◽  
Doris E. Braun ◽  
Volker Kahlenberg ◽  
Klaus Wurst ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Single Crystal ◽  
Crystal Structures ◽  
Organic Cations ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Diffraction Patterns

AbstractThe preparation of six new 5,5′-azotetrazolates with organic cations is reported. Differential scanning calorimetry of all compounds showed exothermic decompositions. The crystal structures of the six 5,5′-azotetrazolates were determined by single-crystal X-ray diffraction analyses. The phase purities of the bulk samples were confirmed by Pawley fits of the experimental and calculated powder X-ray diffraction patterns.

Directional Solidification Behavior of CMSX-6 Superalloy

2014 ◽  
Vol 788 ◽  
pp. 554-559
Author(s):  
Shuai Zheng ◽  
Yu Liang Jia ◽  
Jiao Tang
Keyword(s):  
Single Crystal ◽  
Directional Solidification ◽  
Thermal Gradient ◽  
First Generation ◽  
Primary Dendrite ◽  
Solidification Rate ◽  
Experimental Results ◽  
Single Crystal Superalloy ◽  
Solidification Behavior ◽  
Rate Range

The directional solidification behavior of a first generation single crystal superalloy CMSX-6 was investigated. The solidification rate range in 25μm/s to 100μm/s and a thermal gradient G of 30K/cm were used for the present study. The experimental results show that the primary dendrite arm space (PDAS) decreased from (432±8) μm to (369±4) μm as the solidification rate increased, and the sizes of the eutectic pools also decreased as the solidification rate increased. And the volume fractions of eutectic γ/γ' were about 7% to 9% with different solidification rate. The γ/γ'- eutectic was comprised with coarse γ' phase and fine γ/γ' network. The morphology of the γ/γ’ eutectic supported the possibility that the solidification of γ/γ’ eutectic initiates with the formation of fine γ/γ’.

Low-temperature phase transition in glycine–glutaric acid co-crystals studied by single-crystal X-ray diffraction, Raman spectroscopy and differential scanning calorimetry

2012 ◽  
Vol 68 (3) ◽  
pp. 287-296 ◽  
Author(s):  
Boris A. Zakharov ◽  
Evgeniy A. Losev ◽  
Boris A. Kolesov ◽  
Valeri A. Drebushchak ◽  
Elena V. Boldyreva
Keyword(s):  
Phase Transition ◽  
Differential Scanning Calorimetry ◽  
Raman Spectroscopy ◽  
Single Crystal ◽  
Glutaric Acid ◽  
Group Symmetry ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray

The occurrence of a first-order reversible phase transition in glycine–glutaric acid co-crystals at 220–230 K has been confirmed by three different techniques – single-crystal X-ray diffraction, polarized Raman spectroscopy and differential scanning calorimetry. The most interesting feature of this phase transition is that every second glutaric acid molecule changes its conformation, and this fact results in the space-group symmetry change from P21/c to P\bar 1. The topology of the hydrogen-bonded motifs remains almost the same and hydrogen bonds do not switch to other atoms, although the hydrogen bond lengths do change and some of the bonds become inequivalent.

Processibility and Thermo-Mechanical Properties of Epoxy as Reactive Plasticizer of Polyetherimide

2017 ◽  
Vol 264 ◽  
pp. 228-231
Author(s):  
Nasuha Marzuki ◽  
Muhamad Amirul Ashraf Mohd Alias ◽  
Arjulizan Rusli ◽  
Zulkifli Ahmad
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Early Stage ◽  
Scanning Calorimetry ◽  
Two Phase ◽  
Dispersed Particles ◽  
Epoxy Blends ◽  
Scanning Electron

A relatively new way to improve processibility thermoplastics is via the use of crosslinkable monomers which can act as reactive plasticizers and reduce the viscosity in the early stage of processing. The monomers can polymerize and phase separate during final stage of processing thus recovering the original thermoplastics properties. In this work, the applicability of epoxy as reactive plasticizer for polyetherimide (PEI) was investigated. The properties of PEI/epoxy blends without and with curative were studied in order to determine the effect of the monomer on the processibility of the PEI and the thermo-mechanical properties of cured blends. Differential Scanning Calorimetry on blends without curative indicated single glass transition temperature (Tg) at high PEI content suggesting miscibility of the system and plasticization of PEI in the presence of epoxy while cured blends indicated two Tg due to phase separation. Scanning electron microscopy of the cured blends indicated two phase morphology with PEI dispersed particles size increased in continuous epoxy matrix with increasing PEI (up to 30wt% PEI). In blends with 40wt% PEI and more, phase inverted morphology was observed where increasing PEI content caused reduction of epoxy particle size in continuous PEI matrix.

A Differential Scanning Calorimetric Study of the Mg-Cu-Y System

2012 ◽  
Vol 706-709 ◽  
pp. 1215-1220 ◽  
Author(s):  
Mohammad Mezbahul-Islam ◽  
Elhachmi Essadiqi ◽  
Mamoun Medraj
Keyword(s):  
Differential Scanning Calorimetry ◽  
Metallic Glass ◽  
Thermodynamic Modeling ◽  
Differential Scanning Calorimetric ◽  
Phase Assemblage ◽  
Calorimetric Study ◽  
Solidification Behavior ◽  
Scanning Calorimetry ◽  
Ternary Compounds ◽  
Melting Temperatures

The Mg-Cu-Y system has been experimentally investigated using differential scanning calorimetry (DSC). Vertical sections and phase assemblage diagrams are calculated using thermodynamic modeling. Solidification behavior of the key alloys was discussed in light of the thermodynamic calculation. Melting temperatures of two of the ternary compounds; Mg18CuY and Mg4CuY, are predicted using the modified thermodynamic database of this system. Key words: Mg alloys, Bulk metallic glass, Differential scanning calorimetry, Thermodynamic modeling.

Microstructure, phase relationships and microhardness of Fe60Al40–n Hf n alloys (n = 1, 3, and 5 at.%)

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mehmet Yildirim ◽  
Neşe Çetinbakış ◽  
Ayşe Culu ◽  
M. Vedat Akdeniz ◽  
Amdulla O. Mekhrabov
Keyword(s):  
Differential Scanning Calorimetry ◽  
Magnetic Properties ◽  
Room Temperature ◽  
Eutectic Reaction ◽  
Room Temperature Ferromagnetism ◽  
Eutectic Mixture ◽  
Solidification Behavior ◽  
Micro Structure ◽  
Scanning Calorimetry ◽  
Phase Relationships

Abstract The microstructural evolution, solidification behavior, phase relationships, microhardness and room temperature magnetic properties of the hypoeutectic Fe60Al40-n Hf n (n = 1, 3, and 5 at.%) compositions are investigated in detail. The micro-structure of the studied alloys is composed of Fe–Al based dendrites and eutectic mixture. The components of the eutectic are B2 Fe–Al based and HfFe6Al6 τ1 phases. With increasing Hf fraction, the amounts of eutectic and τ1 phases increase continuously which results in significant strengthening. Based on the differential scanning calorimetry results, the eutectic reaction temperature is measured as 1251 °C. Fe60Al40-n Hf n alloys show weak room temperature ferromagnetism and their magnetization values also increase with increasing Hf content.

scholarly journals Numerical Simulation of Directional Solidification Process of Single Crystal Ni- Based Superalloy Casting

2017 ◽  
Vol 17 (2) ◽  
pp. 111-118 ◽  
Author(s):  
D. Szeliga ◽  
K. Kubiak ◽  
J. Sieniawski
Keyword(s):  
Temperature Gradient ◽  
Single Crystal ◽  
Cooling Rate ◽  
Solidification Rate ◽  
Solidification Process ◽  
Longitudinal Section ◽  
Withdrawal Rate ◽  
Bottom Part ◽  
Rate Maximum ◽  
Predicted Values

Abstract The analysis of influence of mould withdrawal rate on the solidification process of CMSX-4 single crystal castings produced by Bridgman method was presented in this paper. The predicted values of temperature gradient, solidification and cooling rate, were determined at the longitudinal section of casting blade withdrawn at rate from 1 to 6mm/min using ProCAST software. It was found that the increase of withdrawal rate of ceramic mould results in the decrease of temperature gradient and the growth of cooling rate, along blade height. Based on results of solidification parameter G/R (temperature gradient/solidification rate), maximum withdrawal rate of ceramic mould (3.5 mm/min), which ensures lower susceptibility to formation process of new grain defects in single crystal, was established. It was proved that these defects can be formed in the bottom part of casting at withdrawal rate of 4 mm/min. The increase of withdrawal rate to 5 and 6 mm/min results in additional growth of susceptibility of defects formation along the whole height of airfoil.

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