The interfacial reaction and titanium matrix microstructure in continuous SiC fiber-reinforced titanium matrix composite were investigated. By comparison of two samples actuated by 800 ℃ （in α ＋ β dual-phase fiel...The interfacial reaction and titanium matrix microstructure in continuous SiC fiber-reinforced titanium matrix composite were investigated. By comparison of two samples actuated by 800 ℃ （in α ＋ β dual-phase field） and 920 ℃ （in 13 single-phase field） consolidation, it can be concluded that tri-layer interfacial reaction regions con- sisting of fine TiCx/transition TiCx/coarse TiCx are formed in both two samples. In addition, the total thickness of reaction layer for composites prepared at 920℃ is thicker than that consolidated at 800℃, while fine TiCx layer of 920℃ sample is thinner than that of 800 ℃ sample, which may be ascribed to the quick growth of PVD-Ti17 grain manufactured at 920 ℃. In addition, lower interfacial shear strength is obtained in 920 ℃ sample, which can be ascribed to the formation of too thick brittle TiC layer. The research in the work is expected to motivate further exploration for interface adjustment of titanium matrix composites.展开更多
An abnormal phenomenon was investigated in Ti<sub>44</sub>Ni<sub>51</sub>Nb<sub>5</sub> alloy which exhibits an absence of martensite transformation and a negative temperature depen...An abnormal phenomenon was investigated in Ti<sub>44</sub>Ni<sub>51</sub>Nb<sub>5</sub> alloy which exhibits an absence of martensite transformation and a negative temperature dependence of electrical resistivity with the temperature decreasing. X-ray diffraction (XRD) analysis shows the matrix phase keeps a B2 structure during cooling without a martensite transformation, and dynamic mechanical analysis displays a frequency-dependent AC modulus/loss anomaly at T <sub>g</sub> according to Vogel-Fulcher relation. Simultaneously, transmission electronic microscope (TEM) analysis manifests the superlattice spots at near 1/3 commensurate position, implying an existence of strain nanodomains with an R-like structure. And above experiment results provide evidence for the “strain glass” transition in defect-containing ferroelastic Ti<sub>44</sub>Ni<sub>51</sub>Nb<sub>5</sub> alloy.展开更多
基金financially supported by the National Natural Science Foundation of China (No.51571128)
文摘The interfacial reaction and titanium matrix microstructure in continuous SiC fiber-reinforced titanium matrix composite were investigated. By comparison of two samples actuated by 800 ℃ （in α ＋ β dual-phase field） and 920 ℃ （in 13 single-phase field） consolidation, it can be concluded that tri-layer interfacial reaction regions con- sisting of fine TiCx/transition TiCx/coarse TiCx are formed in both two samples. In addition, the total thickness of reaction layer for composites prepared at 920℃ is thicker than that consolidated at 800℃, while fine TiCx layer of 920℃ sample is thinner than that of 800 ℃ sample, which may be ascribed to the quick growth of PVD-Ti17 grain manufactured at 920 ℃. In addition, lower interfacial shear strength is obtained in 920 ℃ sample, which can be ascribed to the formation of too thick brittle TiC layer. The research in the work is expected to motivate further exploration for interface adjustment of titanium matrix composites.
基金financially supported by the National Natural Science Foundation of China(No.51271010)
文摘An abnormal phenomenon was investigated in Ti<sub>44</sub>Ni<sub>51</sub>Nb<sub>5</sub> alloy which exhibits an absence of martensite transformation and a negative temperature dependence of electrical resistivity with the temperature decreasing. X-ray diffraction (XRD) analysis shows the matrix phase keeps a B2 structure during cooling without a martensite transformation, and dynamic mechanical analysis displays a frequency-dependent AC modulus/loss anomaly at T <sub>g</sub> according to Vogel-Fulcher relation. Simultaneously, transmission electronic microscope (TEM) analysis manifests the superlattice spots at near 1/3 commensurate position, implying an existence of strain nanodomains with an R-like structure. And above experiment results provide evidence for the “strain glass” transition in defect-containing ferroelastic Ti<sub>44</sub>Ni<sub>51</sub>Nb<sub>5</sub> alloy.
