The Cu-Sn phase diagram, Part I: New experimental results.
S Fürtauer1, D Li2, D Cupid2
1Institute of Inorganic Chemistry/Materials Chemistry, University of Vienna, Vienna, Austria.
Intermetallics
|April 19, 2016
Summary
This study revises the copper-tin (Cu-Sn) phase diagram by investigating high-temperature phases. New findings reveal a higher-order transformation between beta and gamma phases, impacting thermodynamic assessments.
Area of Science:
- Materials Science
- Metallurgy
- Physical Chemistry
Background:
- The copper-tin (Cu-Sn) system is crucial in various industrial applications.
- Understanding its high-temperature phase behavior is essential for accurate material design and processing.
Purpose of the Study:
- To investigate the high-temperature beta (W-type) and gamma (BiF3-type) phases in the Cu-Sn system.
- To clarify the phase relationships between these high-temperature phases.
- To propose a revised Cu-Sn phase diagram based on experimental evidence and literature review.
Main Methods:
- Thermal analysis (Differential Thermal Analysis - DTA)
- Metallographic analysis (Electron Probe Microanalysis - EPMA, Scanning Electron Microscopy with Energy Dispersive X-ray spectroscopy - SEM-EDX)
- Crystallographic analysis (Powder X-ray Diffraction - XRD, High-Temperature Powder XRD)
Main Results:
- The presence of a two-phase field between the beta and gamma phases could not be confirmed experimentally.
- A higher-order transformation between the beta and gamma high-temperature phases was identified.
- The experimental findings challenge previous phase diagram models for the Cu-Sn system.
Conclusions:
- The study proposes a new version of the Cu-Sn phase diagram incorporating a higher-order transformation.
- This revised diagram provides a more accurate thermodynamic assessment of the Cu-Sn system.
- The findings are presented as Part I of a joint publication, with a full thermodynamic assessment in Part II.
Related Concept Videos
01:19Phase Diagram
7.2K
The phase of a given substance depends on the pressure and temperature. Thus, plots of pressure versus temperature showing the phase in each region provide considerable insights into the thermal properties of substances. Such plots are known as phase diagrams. For instance, in the phase diagram for water (Figure 1), the solid curve boundaries between the phases indicate phase transitions (i.e., temperatures and pressures at which the phases coexist).
7.2K
01:24Phase Diagram
76
A phase diagram is a graphical representation of the physical states of a substance under different conditions of temperature and pressure. It shows the boundaries between solid, liquid, and gas phases and the conditions at which these phases coexist in equilibrium. An area in a phase diagram represents a single phase, whereas lines or phase boundaries represent the equilibrium between two phases.In the phase diagram of water, the boundary line between the solid and liquid states illustrates...
76
02:39Phase Diagrams
51.4K
A phase diagram combines plots of pressure versus temperature for the liquid-gas, solid-liquid, and solid-gas phase-transition equilibria of a substance. These diagrams indicate the physical states that exist under specific conditions of pressure and temperature and also provide the pressure dependence of the phase-transition temperatures (melting points, sublimation points, boiling points). Regions or areas labeled solid, liquid, and gas represent single phases, while lines or curves represent...
51.4K
01:28Phase Diagrams of Ternary Systems
52
Consider a ternary system, which is composed of three components: water (W), ethanoic acid (E), and trichloromethane (T). Here, Ethanoic acid (E) is fully miscible with both water (W) and trichloromethane (T), meaning it can mix entirely with either of them. However, water and trichloromethane have partial miscibility, meaning they can only mix to a certain extent, beyond which two separate phases will form.The phase diagram of a ternary system is represented as an equilateral triangle, where...
52
01:20The Phase Rule
55
The phase rule describes the relationship between the variance (degrees of freedom), the number of components, and the number of phases in a system at equilibrium.Variance is a concept that denotes the number of independent intensive properties (properties are those that do not depend on the amount of material in the system), such as temperature, pressure, and composition, that can be altered without impacting the number of phases in equilibrium.In a single-component system, such as pure water,...
55
02:33Phase Transitions: Sublimation and Deposition
20.8K
Some solids can transition directly into the gaseous state, bypassing the liquid state, via a process known as sublimation. At room temperature and standard pressure, a piece of dry ice (solid CO2) sublimes, appearing to gradually disappear without ever forming any liquid. Snow and ice sublimate at temperatures below the melting point of water, a slow process that may be accelerated by winds and the reduced atmospheric pressures at high altitudes. When solid iodine is warmed, the solid sublimes...
20.8K