Nanocrystalline formation in immiscible Cu-Mo system subjected to mechanical alloying.
The mechanical alloying process has been studied on the Cu-Mo system, the atomic pair of which is characterized by a positive heat of mixing of +19 kJ/mol. The EXAFS and X-ray diffraction measurements have been employed to analyze the structural changes taking place during milling. Two phases mixture of nanocrystalline fcc-Cu and bcc-Mo with a grain size of 10 nm has been formed by MA of Cu30Mo70 powders for 200 hours. The structural analysis based on the EXAFS spectra revealed that bcc and fcc crystal structure clearly do not change around Mo and Cu atoms up to 200 h of milling, respectively. Studies of the thermodynamical considerations by DSC analyses confirmed that the alloying does not occur even after 200 hours of MA in Cu-Mo system.
Lee
Chung-Hyo
CH
Department of Advanced Materials Science and Engineering, Mokpo National University, Muan-gun, Chonnam 534-729, Korea.
Lee
Seong-Hee
SH
D003102:Colloids / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008669:Metallurgy / Q000379:methods*; D008968:Molecular Conformation; D008982:Molybdenum / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D012995:Solubility; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature
D003102:Colloids; D046911:Macromolecular Substances; D003300:Copper; D008982:Molybdenum