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The Investigation of the Melt Structure Transition of Cu-Sb Alloys and Their Correlation with Solidification

Author: MaoLiNa
Tutor: ZuFangZuo
School: Hefei University of Technology
Course: Materials Processing Engineering
Keywords: Cu-Sb alloy Liquid structure Solidification behavior Resistance method
CLC: TG113.12
Type: Master's thesis
Year: 2009
Downloads: 106
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Abstract

Liquid substances on the solidification structure and the basic properties of the solid phase transition and the final microstructure and properties of materials has an important impact. In recent years, liquid substance polymorphic been widespread concern in the scientific community, a lot of material with the liquid structure is found abnormal temperature or pressure changes. These phenomena break the people's tradition of Liquid Structure continuous gradient cognition, cognitive liquid substances for further provides a new breakthrough. Over the years, the alloy melt superheating treatment applied as an important means of improving the microstructure and properties of materials has achieved fruitful results. While people on the thermal history of the melt solidified melt structure effect due to changes in the state, but its essence and rules are not very clear. Liquid discovery and study of structural change, the liquid - solid dependencies cognitive provides a new opportunity, but also to avoid the blindness of the exploration process, but for structural change and its effect on the melt solidified alloys influence regularity and nature needs further exploration. In this paper, a compound formed alloy Cu-Sb alloy for the study, a systematic study of the three components of the liquid alloy structural change their characteristics and laws, and the use of different melt heat treatment discussed two types of reversible and irreversible changes in the melt structure solidification behavior and organizational impact, the main content, innovation and significance are summarized as follows: a study of three components Cu (100-x) Sbx (x = 70,76.5,90) alloy in a continuous process heating and cooling resistivity - temperature behavior and found that at a particular temperature range of memory in the apparent anomalies, suggesting that the liquid structure has two kinds of reversible and irreversible changes. This result demonstrated that, in addition to the previously found Sn-containing alloy melt other than another based alloy - Sb-containing alloy, the temperature of the melt behavior may reversibly change. 2, in order to melt structure transition as the starting point, the use of different cooling rate control alloy melt solidification process, and use a variety of experiments and testing methods were investigated two types of reversible and irreversible structural changes in the melt and solidification behavior of the alloy solidification effects. Study found that: experience becomes irreversible melt solidification undercooling, nucleation rate increased, corresponding to the solidification rate accelerated significantly refined microstructure, and wherein each of precipitation phase morphology will change; hand , for the reversible change in melt processing method changes, can effectively control the melt state, thereby to obtain different final solidification. 3, the research method, the electrical resistance and thermal analysis method used to study the combined melt structure transition before and after the solidification process, verify the resistance method not only can effectively reveal the solidification behavior, with a freezing point of the more obvious advantages of feature, you can also Thermal analysis reveals more than the solidification behavior information. Our results reveal: grasp the melt state prior to temperature change information and rules conducive to more clearly manipulated to effectively control the melt processing temperature solidification. This new phenomenon revealed by the results and rules for a more in-depth understanding of the structure of matter and the nature of the liquid to provide a new basis; technical progress on materials processing has a positive significance.

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CLC: > Industrial Technology > Metallurgy and Metal Craft > Metallurgy and Heat Treatment > Metallurgy ( Physical Metallurgy ) > Metallographic microstructure and properties of the (metal ) > Organization of the metal > Alloy and phase structure
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