Preparation and Oxidation Resistance of BN-MgAlON Composites by Hot-pressing Sintering
Ran LIU1,2,Xin-yuan ZHANG1,2,Xing-juan WANG1,2,Ya-na QIE1,2,Qing L��1,2,Fu GAO1,2
1. Key Laboratory for Advanced Metallurgy Technology of Ministry of Education, Hebei United University, Tangshan 063009, Hebei, China 2. College of Metallurgy and Energy, Hebei United University, Tangshan 063009, Hebei, China
Preparation and Oxidation Resistance of BN-MgAlON Composites by Hot-pressing Sintering
Ran LIU1,2,Xin-yuan ZHANG1,2,Xing-juan WANG1,2,Ya-na QIE1,2,Qing L��1,2,Fu GAO1,2
1. Key Laboratory for Advanced Metallurgy Technology of Ministry of Education, Hebei United University, Tangshan 063009, Hebei, China 2. College of Metallurgy and Energy, Hebei United University, Tangshan 063009, Hebei, China
ժҪ BN-MgAlON composites were prepared by hot-pressing sintering under nitrogen atmosphere with BN-MgAlON composite powders as raw material and Y2O3 as sintering additive. Based on thermodynamic analysis, the oxidation resistance of BN-MgAlON composites was investigated and the dynamics of oxidation process was also analyzed. The oxidation process and the micro-morphology of the samples before and after oxidation were characterized by X-ray diffraction and scanning electron microscopy. The dynamics of oxidation resistance of the BN-MgAlON composites was investigated via the analysis of the constant temperature oxidation mass gain curves. The results show that the main components of the material are MgAlON, Sialon, BN and CaYAl3O7 at 1650-1750 ��, and the content of CaYAl3O7 decreases as the sintering temperature increases. The BN-MgAlON composites prepared at 1750 �� is uniform and compact with the balanced distributions of Al, Mg, O, and N. The oxidation process of BN-MgAlON composites in air mainly consists of MgAlON, Sialon and BN oxidation. The section after being oxidized at 1000-1300 �� involves three layers, namely, the outer layer, the middle layer and the inner layer. The oxidation process follows the parabola model. The apparent activation energy of the oxidation process is 2.13��105 J/mol and the frequency factor is 4.66��106.
Abstract��BN-MgAlON composites were prepared by hot-pressing sintering under nitrogen atmosphere with BN-MgAlON composite powders as raw material and Y2O3 as sintering additive. Based on thermodynamic analysis, the oxidation resistance of BN-MgAlON composites was investigated and the dynamics of oxidation process was also analyzed. The oxidation process and the micro-morphology of the samples before and after oxidation were characterized by X-ray diffraction and scanning electron microscopy. The dynamics of oxidation resistance of the BN-MgAlON composites was investigated via the analysis of the constant temperature oxidation mass gain curves. The results show that the main components of the material are MgAlON, Sialon, BN and CaYAl3O7 at 1650-1750 ��, and the content of CaYAl3O7 decreases as the sintering temperature increases. The BN-MgAlON composites prepared at 1750 �� is uniform and compact with the balanced distributions of Al, Mg, O, and N. The oxidation process of BN-MgAlON composites in air mainly consists of MgAlON, Sialon and BN oxidation. The section after being oxidized at 1000-1300 �� involves three layers, namely, the outer layer, the middle layer and the inner layer. The oxidation process follows the parabola model. The apparent activation energy of the oxidation process is 2.13��105 J/mol and the frequency factor is 4.66��106.
��������:National Natural Science Foundation of China;The Education Department of Hebei Province outstanding youth fund project
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E-mail: 1019004598@qq.com
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Ran LIU,,Xin-yuan ZHANG,,Xing-juan WANG,,Ya-na QIE,,Qing L��,,Fu GAO,. Preparation and Oxidation Resistance of BN-MgAlON Composites by Hot-pressing Sintering[J]. �й������ڿ���, 2015, 22(5): 423-430.
Ran LIU,,Xin-yuan ZHANG,,Xing-juan WANG,,Ya-na QIE,,Qing L��,,Fu GAO,. Preparation and Oxidation Resistance of BN-MgAlON Composites by Hot-pressing Sintering. Chinese Journal of Iron and Steel, 2015, 22(5): 423-430.
2015, Vol. 22 
