The mechanical behaviours of Ti-24Al-11Nb alloy in the brittle-ductile transition (BOT) have been investigated by using three-point bending tests. The temperature dependence of the fractal dimensions and fractal chara...The mechanical behaviours of Ti-24Al-11Nb alloy in the brittle-ductile transition (BOT) have been investigated by using three-point bending tests. The temperature dependence of the fractal dimensions and fractal characterization of fracture surfaces are presented. The probable mechanism controlling BDT of intermetallic alloys are proposed according to fractal geometry.Additionally. it is found that there is a positive relationship between the fractal dimension and fracture toughness in BDT for Ti-24Al-11Nb展开更多
The microcracking behaviour of TiAl-based alloys with the duplex and fully-lamellar microstructures was studied during compression. It was found that the fracture involves propagation of the existing microcracks and d...The microcracking behaviour of TiAl-based alloys with the duplex and fully-lamellar microstructures was studied during compression. It was found that the fracture involves propagation of the existing microcracks and development of more new nuclei, instead of being a nucleation-controlled event. The lamellar interfaces, especially those having an angle of about 0 similar to 30 degrees C to the loading axis, were found to be the favourable nucleation sites. Microcrack nucleation is likely to be initiated by tensile normal stress concentrated on the lamellar interfaces.展开更多
文摘The mechanical behaviours of Ti-24Al-11Nb alloy in the brittle-ductile transition (BOT) have been investigated by using three-point bending tests. The temperature dependence of the fractal dimensions and fractal characterization of fracture surfaces are presented. The probable mechanism controlling BDT of intermetallic alloys are proposed according to fractal geometry.Additionally. it is found that there is a positive relationship between the fractal dimension and fracture toughness in BDT for Ti-24Al-11Nb
文摘The microcracking behaviour of TiAl-based alloys with the duplex and fully-lamellar microstructures was studied during compression. It was found that the fracture involves propagation of the existing microcracks and development of more new nuclei, instead of being a nucleation-controlled event. The lamellar interfaces, especially those having an angle of about 0 similar to 30 degrees C to the loading axis, were found to be the favourable nucleation sites. Microcrack nucleation is likely to be initiated by tensile normal stress concentrated on the lamellar interfaces.
