Microstructural evolution of helium-implanted α-SiC

Microstructural evolution of helium-implanted a-SiC

Helium has a decisive effect on the microstructure of silicon carbide materials after implantation and subsequent annealing. A dense population of bubbles and dislocation loops is already observed at relatively low displacement doses after annealing of helium-implanted a-SiC, while no visible damage appears after irradiation without helium implantation under otherwise equal conditions. The defe...

Characterization of Ni-implanted GaN and SiC

High concentrations ( /10 cm ) of Ni were introduced into GaN and SiC by ion implantation at 350 8C. On subsequent annealing at 700 8C, there was more residual lattice damage in GaN compared to SiC. Both materials showed ferromagnetism with transition temperatures below 50 K. No secondary phases could be detected by transmission electron microscopy (TEM) or selected area diffraction in either G...

Noble gases from the planetary nebula stage of stellar evolution implanted in meteoritic SiC grains

Microstructural Evolution of X45CrNiW189 Valve Steel During Hot Deformation

The hot compression tests were carried on X45CrNiW189 valve steel (X45) in the temperature range of 1000– 1200 °C and the strain rate range of 0.004 – 0.5 s-1 in order to study the high temperature softening behavior of this steel. For the exact prediction of flow stress, the effective stress-effective strain curves were obtained from experiments under various conditions. On the basis of experi...

Evolution of Helium Bubbles and Discs in Irradiated 6H-SiC during Post-Implantation Annealing

The single crystal 6H-SiC with [0001] crystal direction irradiated by 400 keV He⁺ ions with 1 × 1017 ions/cm² fluence at 400 °C were annealed at 600, 900, 1200 and 1400 °C for different durations. The evolution of helium bubbles and discs was investigated by transmission electron microscopy. An irradiated layer distributed with fine helium bubbles was formed with a width of ~170 nm after helium...