Microstructure and Phase Composition of AlN/Al Composite Fabricated by Directed Melt Nitridation
AlN/Al ceramic composite was fabricated by directed melt nitridation of pure Al block covered with 10wt% Mg powder at 1300℃ in a high purity flowing N2.Microstructure and phase composition of the composite were investigated by scanning electron microscopy with energy dispersive spectroscopy and X-ray diffraction.Results showed that AlN is the main phase in the composite and its lattice parameters of a and c are 3.1110(A) and 4.9806(A),respectively.The phase composition of the composite changes along the growth direction and a gradient sandwich structure forms.The surface of the composite is made up of a dense and thin nodular AlN layer,underneath which an AlN/Al layer appears,followed by an AlN/Al/MgAl2O4 layer.Thermodynamic calculations predicted the formation of possible phases with the addition of Mg.It suggested that the content of Mg at the reaction frontier of nitridation is considerably lower to 0.15wt% where MgAl2O4 was stable,because of escape and reaction exhaustion of Mg.Once Mg is lower than 0.05wt%,only a dense AlN layer can exist,which prevents the further nitridation of Al melt.
Aluminum nitride Magnesium Directed melt nitridation Thermodynamic calculation
Shengli Jin Yawei Li Jing Liu Yuanbing Li Lei Zhao Xiaohua Liu Yuee Ni Zeya Li
State Key Laboratory Breeding Base of Refractories and Ceramics,Wuhan University of Science and Tech Shanghai Baosteel Institute,Shanghai 201900,China
国际会议
The Fifth China International Conference on High-Performance Ceramics (第五届先进陶瓷国际研讨会(CICC-5))
长沙
英文
977-979
2007-05-10（万方平台首次上网日期，不代表论文的发表时间）