Thermal stability and grain growth behavior of nanocrystalline Mg2Si

✍ Scribed by L. Wang; X.Y. Qin; W. Xiong; L. Chen; M.G. Kong

• Publisher: Elsevier Science
• Year: 2006
• Tongue: English
• Weight: 166 KB
• Volume: 434
• Category: Article
• ISSN: 0921-5093
• DOI: 10.1016/j.msea.2006.06.130

✦ Synopsis

Thermal stability and grain growth behavior of nanocrystalline Mg 2 Si (nano-Mg 2 Si), prepared by using mechanically activated solid-state reaction plus hot-pressing in vacuum, were investigated by the method of in situ high-temperature X-ray diffraction. The result indicates that the evolution of grain size d with isothermal-annealing time t for nano-Mg 2 Si can be well described by the formula dd 0 = ct 1/n with grain growth exponent n = 6, 5 and 4 at 700, 800 and 900 • C, respectively, indicating that nano-Mg 2 Si has a good thermal stability. Simultaneously, an Arrhenius plot of rate constant c against the reciprocal of T yields a straight line, from which an activation energy of 112 ± 1 kJ/mol is derived for the grain growth of nano-Mg 2 Si.