Evolution of constitution, structure, and mechanical properties in Fe-Ti-Zr-B heterogeneous multiphase composites
- PDF / 396,870 Bytes
- 7 Pages / 584.957 x 782.986 pts Page_size
- 9 Downloads / 189 Views
yang Kima) Center for Non-Crystalline Materials, Department of Metallurgical Engineering, Yonsei University, Seoul 120-749, Republic of Korea
Ki Buem Kim Department of Advanced Materials Engineering, Sejong University, Seoul 143-747, Republic of Korea
Norbert Mattern Leibniz Institute for Solid State and Materials Research Dresden, Institute for Complex Materials, D-01171 Dresden, Germany
Jürgen Eckertb) Leibniz Institute for Solid State and Materials Research Dresden, Institute for Complex Materials, D-01171 Dresden, Germany; and TU Dresden, Institute of Materials Science, D-01062 Dresden, Germany (Received 23 June 2010; accepted 21 September 2010)
The constituent phases, the microstructure, and the mechanical properties of a series of Fe87–xTi7Zr6Bx (x 5 0, 2, 4, 6, 8, 10, and 12) alloys produced by copper mold casting were investigated. Partial substitution of iron by boron in the Fe87Ti7Zr6 ultrafine eutectic alloy induces phase/microstructural evolution and simultaneously changes the mechanical properties. In the composition range of 2 # x # 6, the typical lamellar structure slightly changes into a spherical cellular-type eutectic. For 8 # x # 12, multiphase composites containing a glassy phase form. The ultrafine eutectic composites exhibit a high compressive strength of ~2.9–3.1 GPa and a distinct plasticity of ~2–8%, whereas the glassy matrix composites show a high strength of ~3.1–3.3 GPa but no observable macroscopic plasticity before failure. These findings reveal that the plasticity of heterogeneous multiphase composites is strongly related to the length scale variables and the crystallinity of the constituent phases. I. INTRODUCTION
Rapid solidification has been well known to produce nonequilibrium microstructures and allows for structural refinement, the formation of novel crystalline or amorphous phases, and extension of solid solubility.1 Thus, research on amorphous and nanostructured materials continue to receive great attention, because they show many unique mechanical, physical, and chemical properties in comparison to the corresponding coarse-grained crystalline alloys.2,3 However, these materials deformed mainly by highly localized shear bands, and thus exhibit very limited macroscopic room temperature plasticity before fracture.2,3 To overcome this limitation, hybrid a)
Address all correspondence to this author. e-mail: [email protected] b) This author was an editor of this journal during the review and decision stage. For the JMR policy on review and publication of manuscripts authored by editors, please refer to http://www.mrs. org/jmr_policy DOI: 10.1557/jmr.2010.50 J. Mater. Res., Vol. 26, No. 3, Feb 14, 2011
http://journals.cambridge.org
Downloaded: 19 Jun 2014
composites coexisting of a soft phase in combination with a hard amorphous or complex nano-/ultrafine crystalline matrix have been developed for a variety of alloy systems.4–11 Among them, Fe-based alloys are most attractive for engineering applications, because they possess high strength, good soft magnetic properties, and high
Data Loading...
