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Study on Interface Reaction of Cu-Al-Ni Ternary System

Author: YinHaiLong
Tutor: LiShiChun
School: China University of Petroleum
Course: Materials Science
Keywords: Interfacial reaction Intermetallic compound Diffusion couple Diffusion layer Valence electron structure
CLC: TG111.6
Type: Master's thesis
Year: 2009
Downloads: 134
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Abstract

The interface of dissimilar materials reaction is a common phenomenon in materials science, material connection, powder metallurgy, mechanical alloying, and composite process for the key factors affecting the quality of the final product. Therefore, the study of interfacial reaction law has important theoretical and practical value. This topic using rivets Law Preparation of Cu-Al-Ni ternary diffusion couple, will spread even after annealing at different process conditions, the use of color metallography, microhardness, and scanning electron microscopy testing method interface diffusion layer characteristics were observed and analyzed. The results show that: the interface, interfacial reaction of Cu-Ni is infinite solid solution is formed, the diffusion layer does not have a clear interface, the only change in color, just as the heat treatment temperature increased color change is more obvious. Al-Cu and Al-Ni interface diffusion couple different heat treatment conditions, the interfacial reaction is not the same phenomenon, according to the different features of the diffusion layer, interfacial reactions can be divided into three low temperature, transition and high temperature reaction stage. Incubated for 25-125h, and incubated at 520 ℃ under the conditions of 25-100h, interfacial diffusion layer is relatively narrow, the final interface sub-layer of Al-Cu structure Cu/Cu4Al3/CuAl2/Al; Al-Ni interface sublayer at 500 ℃ structure Ni/Ni2Al3/Al. In 520 ℃ under insulation 125h and 530 ℃ incubated 25-50h of the conditions, an Al-Cu interface solid solution bodies Al (Cu) reaches the eutectic temperature of formation of a liquid phase, rapidly to the Al matrix internal extension of the diffusion layer, eventually forming the alkylene The layer structure Cu/CuAl/CuAl2/Al CuAl2/Al. Al-Ni interface due to the presence of a liquid phase of Al, Ni element is dissolved to form a concentration gradient, the higher concentration is formed at a compound NiAl3 the sublayer structure eventually formed Ni/Ni2Al3/NiAl3/Al. At 540-600 ℃ incubated for different time conditions, the Al matrix is ??completely consumed to form a reaction zone after the eutectic structure is formed inside the reaction zone at 550 ℃ CuAl2 Al, Cu element concentration on the higher place and Cu matrix-forming compound, and ultimately The sublayer structure for Cu/Cu3Al2/Cu4Al3/CuAl/CuAl2/CuAl2 Al. Al-Ni interface still includes two sub-layers, the sublayer structure Ni/Ni2Al3/NiAl3/CuAl2 Al. 600 ° C under the reaction zone is completely CuAl2 occupied, CuAl phase dendritic growth inside the reaction zone includes six sub-layer in the Cu matrix and between the reaction zone, the final sub-layer structure Cu/Cu3Al/Cu9Al4/Cu3Al2/Cu5Al3 / Cu4Al3/CuAl/CuAl2 CuAl. The sub-layer structure of the Al-Ni interface Ni/Ni2Al3/NiAl3/CuAl2 CuAl. The last application EET theoretical valence electron structure of the proliferation of dual matrix and the diffusion layer intermetallic compounds, according to the calculation results of preliminary qualitative analysis of the performance of experimental phenomena and diffusion layer.

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CLC: > Industrial Technology > Metallurgy and Metal Craft > Metallurgy and Heat Treatment > Metallurgy ( Physical Metallurgy ) > Physics of metals > Metal in the diffusion
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