Microstructure and mechanical properties of Nb–Ti–Si–Al–Hf–xCr–yV multi-element in situ composite

The objective of the paper is to investigate the microstructure, room-temperature fracture toughness and high-temperature compressive deformation behavior of Nb–Ti–Si–Al–Hf–Cr–V multi-component Nbss/Nb-silicide in situ composite materials with different Cr and V contents. Nb-silicide presented as the primary phase. Cr and V were assisted to stabilize β-Nb5Si3 to room temperature. The highest value room-temperature fracture toughness (KQ = 14.7 MPa m1/2) preformed in the test for the materials with lowest Cr and V composition. Crack bridging and crack deflection observed in the crack propagation path were benefit to improve the room temperature fracture toughness. Higher V contents up to 4 at.% was preferred to increase the strength of the studied multi-component system at 1250 °C. A softening of materials phenomenon occurred after the peak stress during compressive tests at 1250 °C.