Ti-based bulk metallic glass matrix composites with in situ precipitated β-Ti phase fabricated by spark plasma sintering

摘要

Ti-based bulk metallic glass (BMG) matrix composites with in situ precipitated β-Ti phase were fabricated by spark plasma sintering of amorphous (Ti_(66)Nb_(13)Cu_8Ni_(6.8)Al _(6.2))1B_(0.79)C_(0.65) alloy powder with a wide ΔT_x of 102 K under a sintering pressure of 500 MPa. The wider ΔT_x and the smaller particle size for the as-synthesized (Ti_(66)Nb_(13)Cu_8Ni_(6.8)Al _(6.2))1B_(0.79)C_(0.65) amorphous powder is present compared to B- and C-free amorphous powder. At a sintering temperature of 743 K, spherical nanocrystalline β-Ti with a grain size of 5 nm was homogeneously precipitated in amorphous matrix. Meanwhile, the BMG matrix composite fabricated has a relative density of 98.1% and an amorphous phase volume fraction of 55.2%. However, the BMG matrix composites fabricated exhibit a brittle manner. The results obtained provide an alternative method for fabricating large-sized BMG matrix composites and parts by powder metallurgy.