Formation of Ni<sub>3</sub>Ta, Ni<sub>2</sub>Ta and NiTa by High-Energy Ball Milling and Subsequent Heat Treatment

Abstract

The present work reports on the formation of Ni3Ta, Ni2Ta and NiTa by high-energy ball milling and subsequent heat treatment. The elemental Ni-25Ta, Ni-33Ta and Ni-50Ta (at.-%) powder mixtures were ball milled under Ar atmosphere using stainless steel balls and vials as well as 300 rpm and a ball-to-powder weight ratio of 10:1. Following, the as-milled samples were uniaxially compacted and heat-treated under Ar atmosphere at 1100°C for 4h. The characterization of as-milled and heat-treated samples was conducted by means of X-ray diffraction, scanning electron microscopy, and energy dispersive spectrometry techniques. Supersaturated solid solutions were formed during ball milling of the Ni-25Ta, Ni-33Ta and Ni-50Ta powders. A large amount of Ni3Ta, Ni2Ta and NiTa was formed in the mechanically alloyed heat-treated Ni-25Ta, Ni-33Ta and Ni-50Ta alloys, respectively.