Effect of Fiber Diameter on Quasi-static and Dynamic Compressive Properties of Zr-Based Amorphous Matrix Composites Reinforced with Stainless Steel Continuous Fibers

In this study, two Zr-based amorphous alloy matrix composites reinforced with STS304 stainless steel continuous fibers whose diameters were 110 and 250 μm were fabricated by the liquid pressing process. Using a Hopkinson pressure bar, the compressive deformation behavior was investigated at a strain rate of about 10³ s⁻¹, and the results were then compared with those obtained under quasi-static loading. 65 to 68 vol pct of STS fibers were homogeneously distributed in the amorphous matrix, in which considerable amounts of dendritic crystalline phases were present. According to the dynamic compressive test results, shear cracks were formed at the maximum shear stress direction in the 110-μm-diameter-fiber-reinforced composite to reach the final failure. In the 250-μm-diameter-fiber-reinforced composite, fibers were not cut by shear cracks because the fiber diameter was large enough to restrict the propagation of shear cracks, while taking over a considerable amount of compressive loads over 1500 MPa. This composite showed the higher yield and maximum compressive strengths and plastic strain than the 110-μm-diameter-fiber-reinforced composite because of the sufficient ductility of STS fibers, the effective interruption of propagation of shear cracks, and the strain hardening of fibers themselves.