Combustion characteristics and microstructural evolution of (Mo1-x,Nbx)Si2 (x =0.00-0.50)
The (Mo1-xNbx)Si2 (0≤x≤0.5) was successfully prepared using the combustion synthesis method by Mo,Nb,and Si elemental powders.The influences of niobium on the combustion mode,combustion temperature,combustion velocity and products were investigated.With the increase of Nb content,the combustion temperature of Mo-Nb-Si system increases,while the combustion velocity reduces from 4.977mm/s to 1.988 mm/s.When the x is less than 0.09 in (Mo 1-xNbx)Si2,all the Nb substitutes Mo in MoSi2 during the SHS and the combustion products exhibit C1lb tetragonal MoSi2.However,C40-type structure of NbSi2 appears when x=0.09 and increases with further increase of Nb content.The non-equilibrium SHS process makes supersaturated solid solution effect of Nb to MoSi2,resulting in the continuing expands of the lattice of MoSi2 even when the niobiums amount is far more than its solid solubility limit in Cllb phase of MoSi2.By combustion front quenching technique,it can be found that silicon particles melt during the combustion reaction and the combustion products are formed through melting,dissolution and precipitation mechanism in SHS synthesis.
Combustion synthesis molybdenum disilicide Niobium alloying reaction mechanism
Wang Xiaohong Feng Peizhong Guo Ruixia Shi Jialing Zhang Li Sun Zhi
School of Materials Science and Technology, China University of Mining and Technology,Xuzhou 221116, China
国际会议
上海
英文
267-267
2012-10-19（万方平台首次上网日期，不代表论文的发表时间）