Influence of La and Ce on Microstructure and Properties of Cu-Cr-Zr Alloy

2011 ◽  
Vol 295-297 ◽  
pp. 1168-1174 ◽  
Author(s):  
Jiao Yan Dai ◽  
Si Guo Mu ◽  
Yong Ru Wang ◽  
Xiao Pan Yang ◽  
Jie Li
Keyword(s):  
Free Energy ◽  
Gibbs Free Energy ◽  
Melting Process ◽  
Vacuum Melting ◽  
Microstructure And Properties ◽  
Pine Tree ◽  
Fine Grain ◽  
Zr Alloy

The degassing and dedusting mechanism of La and Ce during non-vacuum melting process of Cu-Cr-Zr alloy were analyzed by thermodynamics. The gibbs free energy changes of reactions of La and Ce with some impurties such as O2, H2, S, P and Si, were calculated to discriminate the possibility of reaction during the melting process, respectively. In addition, the effect of La and Ce on microstructure and properties were studied. The results show that La and Ce can react with O2, H2, S, P and Si, which improves the effect of degassing and dedusting remarkably; the addition of La and Ce can eliminate pine-tree crystal, fine grain and clear grain bourdary.

Study on Microstructure and Properties of Cu-14Fe-0.05C Alloy Prepared by Drawing

2020 ◽  
Vol 996 ◽  
pp. 137-141
Author(s):  
Wei Guo ◽  
De Ping Lu ◽  
Jiang Jiang ◽  
Ke Ming Liu
Keyword(s):  
Melting Process ◽  
Copper Matrix ◽  
Cast State ◽  
Vacuum Melting ◽  
Microstructure And Properties ◽  
Drawing Direction

Cu-14Fe-0.05C alloy was prepared by using the vacuum melting process and then multipass drawing deformation was performed. The results showed that with rise of drawing strain, iron-rich phases in the Cu-14Fe-0.05C alloy gradually change from irregularly distributed coarse dendritic phases in the as-cast state to slender fibrous ones distributed parallel along the drawing direction. The higher the strain is, the slender and denser the fibers are and the more uniform the distribution is. Moreover, more interfaces are found between copper matrix and iron-rich phases and the hardness and resistivity of the alloy become higher.

Effect of Annealing on the Microstructure and Properties of Drawn Cu-14Fe-0.05C Alloy

2020 ◽  
Vol 996 ◽  
pp. 125-130
Author(s):  
Wei Guo ◽  
De Ping Lu ◽  
Jiang Jiang ◽  
Ke Ming Liu
Keyword(s):  
Electrical Conductivity ◽  
Tensile Strength ◽  
Annealing Time ◽  
Annealing Temperature ◽  
Mechanical Performance ◽  
Melting Process ◽  
Vacuum Melting ◽  
Microstructure And Properties

Cu-14Fe-0.05C alloy was prepared by using the vacuum melting process and then multipass drawing deformation was performed. After that, the alloy in the as-drawn state was annealed. Based on this, the influence of annealing temperature on microstructure, mechanical performance and electrical conductivity of the alloy was studied. The results showed that the speed of recovery and recrystallization of the as-drawn Cu-14Fe-0.05C alloy accelerates and iron-rich fibers gradually become slender, bend and fracture, with the increase of annealing temperature. The tensile strength of the alloy constantly decreases, while elongation continuously rises and resistivity gradually reduces. With the extension of annealing time, tensile strength and resistivity of the Cu-14Fe-0.05C alloy gradually decreases, while elongation gradually increases.

Chemical equilibrium and chemical kinetics

2018 ◽  
Author(s):  
Dennis Sherwood ◽  
Paul Dalby
Keyword(s):  
Free Energy ◽  
Equilibrium Constant ◽  
Gibbs Free Energy ◽  
Chemical Kinetics ◽  
Chemical Equilibrium ◽  
First Principles ◽  
Effect Of Temperature ◽  
Total System ◽  
Free Energies

Building on the previous chapter, this chapter examines gas phase chemical equilibrium, and the equilibrium constant. This chapter takes a rigorous, yet very clear, ‘first principles’ approach, expressing the total Gibbs free energy of a reaction mixture at any time as the sum of the instantaneous Gibbs free energies of each component, as expressed in terms of the extent-of-reaction. The equilibrium reaction mixture is then defined as the point at which the total system Gibbs free energy is a minimum, from which concepts such as the equilibrium constant emerge. The chapter also explores the temperature dependence of equilibrium, this being one example of Le Chatelier’s principle. Finally, the chapter links thermodynamics to chemical kinetics by showing how the equilibrium constant is the ratio of the forward and backward rate constants. We also introduce the Arrhenius equation, closing with a discussion of the overall effect of temperature on chemical equilibrium.

Extended Gibbs Free Energy and Laplace Pressure of Ordered Hexagonal Close-Packed Spherical Particles: A Wettability Study

Langmuir ◽  
2021 ◽  
Author(s):  
Amir Bayat ◽  
Mahdi Ebrahimi ◽  
Saeed Rahemi Ardekani ◽  
Esmaiel Saievar Iranizad ◽  
Alireza Zaker Moshfegh
Keyword(s):  
Free Energy ◽  
Gibbs Free Energy ◽  
Laplace Pressure ◽  
Spherical Particles ◽  
Hexagonal Close Packed

scholarly journals First-Principles Study of Mechanical and Thermodynamic Properties of Binary and Ternary CoX (X = W and Mo) Intermetallic Compounds

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1404
Author(s):  
Yunfei Yang ◽  
Changhao Wang ◽  
Junhao Sun ◽  
Shilei Li ◽  
Wei Liu ◽  
...  
Keyword(s):  
Free Energy ◽  
Thermodynamic Properties ◽  
Gibbs Free Energy ◽  
Density Functional ◽  
Vibrational Entropy ◽  
Functional Theory ◽  
Lattice Constants ◽  
The Density Functional Theory ◽  
Ductile Behavior ◽  
Pseudo Potential

In this study, the structural, elastic, and thermodynamic properties of DO19 and L12 structured Co3X (X = W, Mo or both W and Mo) and μ structured Co7X6 were investigated using the density functional theory implemented in the pseudo-potential plane wave. The obtained lattice constants were observed to be in good agreement with the available experimental data. With respect to the calculated mechanical properties and Poisson’s ratio, the DO19-Co3X, L12-Co3X, and μ-Co7X6 compounds were noted to be mechanically stable and possessed an optimal ductile behavior; however, L12-Co3X exhibited higher strength and brittleness than DO19-Co3X. Moreover, the quasi-harmonic Debye–Grüneisen approach was confirmed to be valid in describing the temperature-dependent thermodynamic properties of the Co3X and Co7X6 compounds, including heat capacity, vibrational entropy, and Gibbs free energy. Based on the calculated Gibbs free energy of DO19-Co3X and L12-Co7X6, the phase transformation temperatures for DO19-Co3X to L12-Co7X6 were determined and obtained values were noted to match well with the experiment results.

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