We investigate the effects of 2 MeV Ni+ ion beam irradiation with various fluence ranging from 15 × 1011 to 60 × 1014 ions/cm2 on the surface, structural and mechanical properties of Cu-Zn alloy. The modific...We investigate the effects of 2 MeV Ni+ ion beam irradiation with various fluence ranging from 15 × 1011 to 60 × 1014 ions/cm2 on the surface, structural and mechanical properties of Cu-Zn alloy. The modification in target properties after irradiation is confirmed by using various characterization techniques viz. SEM, XRD, UTM and Vickers micro-hardness tester. The SEM results illustrate the formation of nano sized craters with different diameters. Their average diameter decreases from 190 nm to 90 nm by increasing ion fluence. The XRD analysis of irradiated targets reveals that Ni+ ion irradiation enhances the growth of (111) phase and its peak position varies due to ion induced tensile stresses in target matrix. Tensile and Vickers micro-hardness tests verify the mechanical properties of Cu-Zn alloy reduce monotonically upon irradiation. Various mechanisms such as generation, recombination, augmentation and annihilation of ion induced defects are responsible for this reduction. Understanding the relationships between various modified properties of irradiated target is essential for growing new advanced material by irradiation.展开更多
Brass targets were irradiated with various laser pulses of Excimer laser ranging from 1200 to 3000 for constant fluence of 3.4 J/cm2 in oxygen atmosphere (100 Torr). The surface morphology and crystallographic analyse...Brass targets were irradiated with various laser pulses of Excimer laser ranging from 1200 to 3000 for constant fluence of 3.4 J/cm2 in oxygen atmosphere (100 Torr). The surface morphology and crystallographic analyses were performed by using Scanning Electron Microscope (SEM) and X-Ray Diffractometer (XRD). SEM analysis reveals the formation of laser-induced micro-sized cavities, bumps, cones and wave-like ridges with non-uniform shape and density distribution. These features are formed for all number of pulses;however with increasing number of pulses from 1200 to 2400, the density of cavities decreases whereas, the wave-like ridges become more pronounced and bump-formation is vanished. For maximum number of 3000 shots, the appearance of cones and wave-like ridges becomes diffusive, whereas the density and size of cavities increase again. XRD analysis demonstrates that no new phases are formed in irradiated brass. However, the change in peak intensity along with lower and higher angle shifting is observed which is attributed to generation of laser induced stresses. The Yield Stress (YS), Ultimate Tensile Strength (UTS) as well as Microhardness increase monotonically with increasing number of laser pulses.展开更多
文摘We investigate the effects of 2 MeV Ni+ ion beam irradiation with various fluence ranging from 15 × 1011 to 60 × 1014 ions/cm2 on the surface, structural and mechanical properties of Cu-Zn alloy. The modification in target properties after irradiation is confirmed by using various characterization techniques viz. SEM, XRD, UTM and Vickers micro-hardness tester. The SEM results illustrate the formation of nano sized craters with different diameters. Their average diameter decreases from 190 nm to 90 nm by increasing ion fluence. The XRD analysis of irradiated targets reveals that Ni+ ion irradiation enhances the growth of (111) phase and its peak position varies due to ion induced tensile stresses in target matrix. Tensile and Vickers micro-hardness tests verify the mechanical properties of Cu-Zn alloy reduce monotonically upon irradiation. Various mechanisms such as generation, recombination, augmentation and annihilation of ion induced defects are responsible for this reduction. Understanding the relationships between various modified properties of irradiated target is essential for growing new advanced material by irradiation.
文摘Brass targets were irradiated with various laser pulses of Excimer laser ranging from 1200 to 3000 for constant fluence of 3.4 J/cm2 in oxygen atmosphere (100 Torr). The surface morphology and crystallographic analyses were performed by using Scanning Electron Microscope (SEM) and X-Ray Diffractometer (XRD). SEM analysis reveals the formation of laser-induced micro-sized cavities, bumps, cones and wave-like ridges with non-uniform shape and density distribution. These features are formed for all number of pulses;however with increasing number of pulses from 1200 to 2400, the density of cavities decreases whereas, the wave-like ridges become more pronounced and bump-formation is vanished. For maximum number of 3000 shots, the appearance of cones and wave-like ridges becomes diffusive, whereas the density and size of cavities increase again. XRD analysis demonstrates that no new phases are formed in irradiated brass. However, the change in peak intensity along with lower and higher angle shifting is observed which is attributed to generation of laser induced stresses. The Yield Stress (YS), Ultimate Tensile Strength (UTS) as well as Microhardness increase monotonically with increasing number of laser pulses.