Fabrication of Mg2Si thermoelectric materials by mechanical alloying and spark-plasma sintering process.
A mixture of pure Mg and Si powders with an atomic ratio 2:1 has been subjected to mechanical alloying (MA) at room temperature to prepare the Mg2Si thermoelectric material. Mg2Si intermetallic compound with a grain size of 50 nm can be obtained by MA of Mg66.7Si33.3 powders for 60 hours and subsequently annealed at 620 degrees C. Consolidation of the MA powders was performed in a spark plasma sintering (SPS) machine using graphite dies up to 800-900 degrees C under 50 MPa. The shrinkage of consolidated samples during SPS was significant at about 250 degrees and 620 degrees C. X-ray diffraction data shows that the SPS compact from 60 h MA powders consolidated up to 800 degrees C consists of only nanocrystalline Mg2Si compound with a grain size of 100 nm.
Lee
Chung-Hyo
CH
Department of Advanced Materials Science and Engineering, Mokpo National University, Muan-gun, Chonnam, 534-729, Korea.
Lee
Seong-Hee
SH
Chun
Sung-Yong
SY
Lee
Sang-Jin
SJ
D001672:Biocompatible Materials; D002152:Calorimetry, Differential Scanning; D003460:Crystallization; D004560:Electricity; D008274:Magnesium / Q000737:chemistry*; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods; D011312:Pressure; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature; D014961:X-Ray Diffraction
D001672:Biocompatible Materials; D008274:Magnesium; D012825:Silicon