Enhanced thermal stability of a cobalt–boron carbide nanocomposite by ion-implantation

• Published in: International journal of materials research Vol. 98; no. 11; pp. 1124 - 1130
• Main Authors: daSilva, Melina, Klement, Uta, Hibbard, Glenn D.
• Format: Journal Article
• Language: English
• Published: Munich De Gruyter 01.11.2007; Hanser
• Subjects: Applied sciences; Cobalt – boron carbide; Exact sciences and technology; Focused ion beam; Ion-implantation; Metals. Metallurgy; Nanocomposite; Other surface treatments; Production techniques; Surface treatment; Thermal stability; Ion implantation; Cobalt-boron carbide; Focused ion beam; Ion beam; Nanocomposite; Composite material; Boron carbide; Thermal stability; Surface treatment; Ion-implantation
• ISSN: 1862-5282; 2195-8556
• DOI: 10.3139/146.101571

A first investigation of the thermal stability in a wear resistant cobalt-boron carbide (Co – B C) nanocomposite has been performed by the combination of calorimetry and transmission electron microscopy. The calorimetric measurements show that the thermal stability of Co – B C is not influenced by the presence of the 10 vol.% μm-sized boron carbide particles. However, grain growth is shifted to significantly higher temperatures during in-situ annealing (in the transmission electron microscope), and abnormal grain growth is not observed to be as extensive as in conventional nanocrystalline Co. This effect is mainly attributed to the observed implantation of Ga atoms during transmission electron microscope specimen thinning by focused ion beam. Grain boundary segregation mechanisms are discussed as possible reasons for the retarded grain growth.