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Title: Transmission electron microscopy study of interfacial microstructure formed by reacting Al-Mg alloy with mullite at high temperature

Abstract

Transmission electron microscopy (TEM) has been used to study the interfacial microstructure formed by reacting Al-Mg alloy with mullite (Al{sub 6}Si{sub 2}O{sub 13}) at high temperature (> 900 C). The TEM study was used in order to understand the strong effect of Mg addition on the nature of the reaction between Al and mullite used to form Al/Al{sub 2}O{sub 3} composite. After reaction at 1,050 C, the formation of a layered structure between the Al-1% Mg alloy and mullite was observed. An alloy layer with a much higher concentration of Mg than the starting alloy was found present next to the initial mullite surface. Between the alloy layer and mullite, a dense and continuous layer made of small MgAl{sub 2}O{sub 4} (spinel) and Si particles was present. The layer apparently stopped further reaction between Al-Mg alloy and mullite by preventing transport of the metals to the reaction front and the Si reaction product away from the reaction front. The microstructure resulting from the initial reaction indicated the reaction proceeded by replacing Si atoms with Al and Mg atoms on mullite (210) lattice planes and forming MgAl{sub 2}O{sub 4} (311) lattice planes simultaneously.

Authors:
 [1]; ; ;  [2]
  1. New Mexico Inst. of Mining and Technology, Socorro, NM (United States). Dept. of Materials Science and Engineering
  2. Sandia National Lab., Albuquerque, NM (United States). Advanced Materials Lab.
Publication Date:
Research Org.:
Sandia National Laboratory
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
684405
DOE Contract Number:  
AC04-94AL85000
Resource Type:
Journal Article
Journal Name:
Acta Materialia
Additional Journal Information:
Journal Volume: 47; Journal Issue: 10; Other Information: PBD: 10 Aug 1999
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; MICROSTRUCTURE; ALUMINIUM ALLOYS; MAGNESIUM ALLOYS; MULLITE; COMPOSITE MATERIALS; INTERFACES; CHEMICAL REACTIONS; TEMPERATURE RANGE 1000-4000 K; TRANSMISSION ELECTRON MICROSCOPY; DATA

Citation Formats

Lu, P., Loehman, R.E., Ewsuk, K.G., and Fahrenholtz, W.G. Transmission electron microscopy study of interfacial microstructure formed by reacting Al-Mg alloy with mullite at high temperature. United States: N. p., 1999. Web. doi:10.1016/S1359-6454(99)00176-7.
Lu, P., Loehman, R.E., Ewsuk, K.G., & Fahrenholtz, W.G. Transmission electron microscopy study of interfacial microstructure formed by reacting Al-Mg alloy with mullite at high temperature. United States. doi:10.1016/S1359-6454(99)00176-7.
Lu, P., Loehman, R.E., Ewsuk, K.G., and Fahrenholtz, W.G. Tue . "Transmission electron microscopy study of interfacial microstructure formed by reacting Al-Mg alloy with mullite at high temperature". United States. doi:10.1016/S1359-6454(99)00176-7.
@article{osti_684405,
title = {Transmission electron microscopy study of interfacial microstructure formed by reacting Al-Mg alloy with mullite at high temperature},
author = {Lu, P. and Loehman, R.E. and Ewsuk, K.G. and Fahrenholtz, W.G.},
abstractNote = {Transmission electron microscopy (TEM) has been used to study the interfacial microstructure formed by reacting Al-Mg alloy with mullite (Al{sub 6}Si{sub 2}O{sub 13}) at high temperature (> 900 C). The TEM study was used in order to understand the strong effect of Mg addition on the nature of the reaction between Al and mullite used to form Al/Al{sub 2}O{sub 3} composite. After reaction at 1,050 C, the formation of a layered structure between the Al-1% Mg alloy and mullite was observed. An alloy layer with a much higher concentration of Mg than the starting alloy was found present next to the initial mullite surface. Between the alloy layer and mullite, a dense and continuous layer made of small MgAl{sub 2}O{sub 4} (spinel) and Si particles was present. The layer apparently stopped further reaction between Al-Mg alloy and mullite by preventing transport of the metals to the reaction front and the Si reaction product away from the reaction front. The microstructure resulting from the initial reaction indicated the reaction proceeded by replacing Si atoms with Al and Mg atoms on mullite (210) lattice planes and forming MgAl{sub 2}O{sub 4} (311) lattice planes simultaneously.},
doi = {10.1016/S1359-6454(99)00176-7},
journal = {Acta Materialia},
number = 10,
volume = 47,
place = {United States},
year = {1999},
month = {8}
}