Coarsening of Mo grains in the molten NiFe matrix of a low volume fraction

✍ Scribed by Sung Soo Kim; Duk N. Yoon

• Publisher: Elsevier Science
• Year: 1985
• Weight: 639 KB
• Volume: 33
• Category: Article
• ISSN: 0001-6160
• DOI: 10.1016/0001-6160(85)90146-4

✦ Synopsis

Aktrrct-The

growth pattern of close-packed grains in a 96Mo-3.5Ni-0.5Fe (by wt%) alloy at the liquid-phase sintering temperature of 1430°C has been investigated via etch boundaries formed in the grains during a cyclic heat-treatment. The observed growth pattern is highly asymmetrical as a result of strong interaction between the neighbouring grains in contact. But the net growth rate of each grain appears to increase with its size. The flatness of the liquid film boundaries and their small thickness relative to the cross-sections of bulk liquid at the grain edges and comers indicate that the grain growth is limited by the migration of liquid pockets at the four grain comers, which occurs by solution and reprecipitation between the grain surfaces surrounding them. Based on these observations, it is proposed that the average grain growth can be still described by Ostwald ripening theories. The observed growth patterns of the grains do not show any evidence for the coalescence mechanism.

R&nmGNous