Temperature Effects on the Strength and Toughness of Be12Nb

Abstract

ABSTRACTStrength and toughness of single-phase Be12Nb have been assessed at temperatures from ambient to 1200°C using four-point-bend and hardness tests. Vacuum-hot-pressed beryllide exhibits low bend strengths (∼110 MPa) and fracture toughnesses (∼2.5 MPa√m) at temperatures up to 500C. Measured bend strength then increases to a maximum at 1000°C, while KlC slowly increases through 1100 C. Significant plastic deformation is only observed at 1200 C for the test strain rate of 2×10−6/s. Hardness values were found to remain relatively constant at temperatures up to 800 C and then sharply decrease at higher temperatures. Results indicate that low toughness limits bend strength at temperatures below ∼1000 C and prompts the observed increase in strength at high temperatures.