Phase formation and physical properties of mechanically alloyed amorphous 55Mg35Ni10Si Dengke Yang a , Cui’e Wen b , Fusheng Han a, * , Yujie Yang a a Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, China b School of Engineering and Technology, Deakin University, Geelong, Vic. 3217, Australia Received 19 October 2005; received in revised form 27 April 2006 Abstract Amorphous 55Mg35Ni10Si alloy powder has been synthesized by mechanical alloying technique using pure Mg, Ni and Si elemental powders. The transformation of the crystalline powders into an amorphous one has been investigated by X-ray diffraction, scanning elec- tron microscopy, transmission electron microscopy and differential scanning calorimetry. The new material produced has a higher ther- mal stability than reported results, which is beneficial to the fabrication of Mg–Ni–Si bulk amorphous components through powder metallurgy. Ó 2006 Elsevier B.V. All rights reserved. PACS: 61.43.Dq; 81.05.Zx; 81.20.Ev Keywords: Amorphous metals; Metallic glasses; Alloys; Mechanical alloying; Crystallization; Glass formation; Microstructure 1. Introduction Mg alloys are well known light-weight alloy systems with outstanding specific mechanical properties that will find applications in a number of engineering fields [1]. Unfortunately, the plasticity and the toughness of Mg alloys are usually unsatisfactory and therefore, implemen- tation treatments have to be conducted to improve these properties. As is widely reported, metallic materials with nano-grains show extraordinary physical and mechanical properties and this suggests that the plasticity and the toughness of the Mg alloys can be modified if the grains are tailored into nanometer dimensions. Among others, amorphous route has been proved to be one of the most effective technologies in producing nanocrystalline struc- tures through crystallization [2–6]. There are several ways to produce Mg based amorphous alloys including mechan- ical alloying (MA) [7–9]. The main Mg based amorphous ternary alloy powders prepared via MA include Mg–Y– Cu [10,11], Mg–Ni–Ge [12], Mg–Ni–Sn [13], Mg–Ni–Y [14,15], and Mg–Al–Ca [16]. The selection of ternary alloy system may be based on the fact that they have relatively strong glass formation ability in comparison of binary alloys [17]. However, although these Mg ternary systems have very strong glass forming ability, they have relatively low crystallization temperatures, which is unfavorable for production of bulk amorphous component through hot pressing or extrusion. It has been proved that Ni has a rather high amorphous forming ability and Si tends to ele- vate the glass transition temperature of Mg based amor- phous materials, and thus elemental Mg, Ni and Si powders were selected as starting materials in the present study. The MA processing parameters and alloy composi- tions were investigated with the objective of fabricating a new ternary Mg based amorphous powder with a relatively high crystallization temperature. It is expected that the new ternary Mg–Ni–Si amorphous alloy powder will be suitable for developing bulk amorphous components that will be useful in automobile parts, portable electric appliances, 0022-3093/$ - see front matter Ó 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.jnoncrysol.2006.05.027 * Corresponding author. Tel.: +86 551 5591435; fax: +86 551 5591434. E-mail address: fshan@issp.ac.cn (F. Han). www.elsevier.com/locate/jnoncrysol Journal of Non-Crystalline Solids 352 (2006) 3244–3248