Phase Transformations in Mechanically Alloyed and Sintered Ti-XMg-22Si-11B (X = 2 and 7 at.-%at) Powders

Abstract:

This work reports on effect of magnesium addition on the Ti₆Si₂B stability in Ti-xMg-22Si-11B (x = 2 and 6 at.-%) alloys prepared by high-energy ball milling and subsequent sintering. Ball milling was conducted under Ar atmosphere in stainless steel vials and balls, 300 rpm, and a ball-to-powder weight ratio of 10:1. Following, the powders milled for 10 h were axially compacted in order to obtain cylinder samples with 6 mm diameter. To obtain the equilibrium structures the green samples were sintered at 1100°C for 4 h under Ar atmosphere. X-ray diffraction, scanning electron microscopy and energy dispersive spectrometry were used to characterize the as-milled powders and sintered samples. Extended Ti solid solution were found in the Ti-2Mg-22Si-11B and Ti-7-Mg-Si-B powders milled for 20 min and 60 min, respectively, whereas an amorphous halo was produced on Ti-2Mg-22Si-11B powders milled for 420 min. The increase of Mg amount in the starting powder mixture has inhibited the Ti₆Si₂B formation in the mechanically alloyed and sintered Ti-7Mg-22Si-11B alloy.

• Periodical: Materials Science Forum (Volume 899)
• Pages: 3-8
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.899.3
• Online since: July 2017
• Authors: Luiz Otávio Vicentin Maruya*, Bruno Bacci Fernandes, Mario Ueda, Alfeu Saraiva Ramos
• Keywords: High-Energy Ball Milling, Phase Transformation, Sintering, Titanium Alloy

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