Compressive and Tensile Properties of Tungsten-Continuous-Fiber-Reinforced Zr-Based Amorphous Alloy Matrix Composite Fab
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MARKABLE advances in amorphous alloys have been made because amorphous alloys with high glassforming ability have been developed by conventional casting methods.[1–5] Among these alloys, Zr-based amorphous alloys, in particular, possess a very high glass-forming ability (critical cooling rate: about 1 C/s; maximum sample diameter: 50 to approximately 60 mm), together with high hardness, stiffness, strength, and corrosion resistance,[1,3] and thus have been used in high-performance structural components such as electronic parts, sporting goods, and defense industry parts. However, Zr-based amorphous alloys have poor ductility because brittle fracture readily occurs, due to the formation of localized shear bands under tensile or compressive loading condition,[6,7] thereby limiting wide application in advanced structural materials. Thus, if
KYUHONG LEE, Postdoctoral Research Associate, is with the Center for Advanced Aerospace Materials, Pohang University of Science and Technology, Pohang, 790-784, Korea. SUNGHAK LEE, Professor, Center for Advanced Aerospace Materials, is jointly appointed with Materials Science and Engineering, Pohang University of Science and Technology. Contact email: [email protected] SANG-BOK LEE and SANG-KWAN LEE, Senior Researchers, are with the Composite Materials Laboratory, Korea Institute of Materials Science, Changwon, 641-010, Korea. Manuscript submitted December 14, 2007. Article published online April 16, 2008 METALLURGICAL AND MATERIALS TRANSACTIONS A
the fabrication of amorphous alloy matrix composites, in which secondary phases or reinforcements are homogeneously dispersed in the amorphous alloy matrix, can be newly developed, the aforementioned problems of amorphous alloys can be solved while their advantages are retained. Methods of fabricating amorphous matrix composites include the addition of crystalline particles to the amorphous melt,[8,9] the casting of both reinforcing fibers and amorphous alloys,[10,11] the generation of dendritic crystalline phases from the amorphous melt,[12] and the partial crystallization of amorphous alloys to disperse nanocrystallines.[13,14] In order to effectively fabricate amorphous matrix composites reinforced with metallic continuous fibers, it is necessary to introduce new-concept fabrication technologies, one of which is a liquid pressing process.[15] Because this process uses low pressure—nearly the theoretically required minimum loading pressure, in fact—the crystallization of the amorphous matrix can be prevented or minimized by the rapid cooling of the amorphous melt. This process also has the advantage of complete infiltration of the melt inside the fiber preform, due to the application of low hydrostatic pressure and the elimination of the pores formed by contraction during solidification. This process can also be used in the fabrication of large-scale amorphous composites reinforced with two- or three-dimensional fibers as well as with one-dimensional continuous fibers. In this study, tungsten continuous fibers that have high strength and therm
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