Directional Solidification and Characterization of Hg1−xCdxTe Alloys

1981 ◽  
Vol 9 ◽  
Author(s):  
S. L. Lehoczky ◽  
F. R. Szofran
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Temperature Gradient ◽  
Directional Solidification ◽  
Fluid Flows ◽  
Heat Transfer Characteristics ◽  
Growth Interface ◽  
Compositional Variations ◽  
Best Fit

ABSTRACTA series of Hg1−xCdxTe alloy crystals was grown by high-temperature-gradient directional solidification at furnace translation rates ranging from 0.068 to 1.12 μm/s. For several ingots, the measured longitudinal compositional profiles were fitted to theoretical profiles to estimate the magnitude of D, the liquid HgTe-CdTe interdiffusion coefficient. The best-fit value of D was about 5.5 × 105 cm2/s. The majority of the ingots showed significant radial compositional variations along the growth axis. These variations are attributed, at least in part, to fluid flows ahead of the growth interface. The results are discussed in terms of the heat transfer characteristics of the alloy/ampule/ furnace system and the effects of these characteristics on the shape and stability of the growth interface in a 1-g environment.

High Temperature Rupture Life of Nickel-Based Superalloy under Directional Solidification with High Temperature Gradient

2017 ◽  
Vol 898 ◽  
pp. 422-429 ◽  
Author(s):  
Wei Guo Zhang ◽  
Zhi Jie Liu ◽  
Song Ke Feng ◽  
Fu Zeng Yang ◽  
Lin Liu
Keyword(s):  
High Temperature ◽  
Temperature Gradient ◽  
Directional Solidification ◽  
Temperature Stress ◽  
Solidification Rate ◽  
Rupture Life ◽  
Stress Rupture ◽  
High Temperature Stress ◽  
Stress Rupture Life ◽  
Nickel Based Superalloy

The stress rupture life of DZ125 nickel-based superalloy that was prepared by directional solidification process under the temperature gradient of 500 K/cm has been studied at 900°C and 235MPa. The results showed that with the increase of directional solidification rate from 50 μm/s to 800 μm/s, the primary dendrite arm spacing reduced from 94 μm to 35.8 μm and γ' precipitates reduced and more uniformed in size. The high temperature stress rupture life of as-cast sample increased firstly and then decreased and reached its maximum at the solidification rate of 500 μm/s. The dislocation configuration of sample with refine dendritic structure after stress rupture was investigated and discovered that the dislocations in different parts of sample had different morphology and density, which indicated that the deformation of as-cast samples were uneven during high temperature stress rupture. A lot of dislocations intertwined around carbides and at the interface of γ/γ', and the dislocation networks were destroyed and the dislocations entered γ' precipitate by the way of cutting.

Forming of Porous Micro-Features Using Hot Compaction

2007 ◽  
Author(s):  
Peng Chen ◽  
Gap-Yong Kim ◽  
Jun Ni
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Mass Production ◽  
Heat Transfer Characteristics ◽  
High Productivity ◽  
Powder Consolidation ◽  
Micro Scale ◽  
Hot Compaction ◽  
Micro Features ◽  
High Temperature Operation

Porous metallic micro-scale features are becoming important in the modern industry. However, a mass production of such features is a challenge when robustness, cost-effectiveness, and high productivity requirements are considered. In this study, the fabrication of such porous micro-features using hot compaction was investigated. A hot compaction experiment setup was designed and fabricated, which was capable of high temperature operation (up to 700 °C), quick heat-up, and avoiding oxidation of workpiece and tools. A 3D thermal simulation of the experiment setup was conducted to understand the heat transfer characteristics of the system, which was used as a reference for the experiment. The effects of compression loading force and temperature on the compact quality in terms of powder consolidation strength and porosity were studied.

scholarly journals Performance of Siloxane Mixtures in a High-Temperature Organic Rankine Cycle Considering the Heat Transfer Characteristics during Evaporation

Energies ◽  
2014 ◽  
Vol 7 (9) ◽  
pp. 5548-5565 ◽  
Author(s):  
Theresa Weith ◽  
Florian Heberle ◽  
Markus Preißinger ◽  
Dieter Brüggemann
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics

Heat transfer characteristics during jet impingement on a high-temperature plate surface

2016 ◽  
Vol 100 ◽  
pp. 902-910 ◽  
Author(s):  
Bingxing Wang ◽  
Dong Lin ◽  
Qian Xie ◽  
Zhaodong Wang ◽  
Guodong Wang
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Jet Impingement ◽  
Plate Surface ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics
Sign in / Sign up

Export Citation Format

Share Document