Modifications in surface, structural and mechanical properties of brass using laser induced Ni plasma as an ion source

Abstract

Laser induced Ni plasma has been employed as source of ion implantation for surface, structural and mechanical properties of brass. Excimer laser (248 nm, 20 ns, 120mJ and 30 Hz) was used for the generation of Ni plasma. Thomson parabola technique was employed to estimate the energy of generated ions using CR39 as a detector. In response to stepwise increase in number of laser pulses from 3000 to 12000, the ion dose varies from 60 × 1013 to 84 × 1016 ions/cm2 with constant energy of 138 KeV. SEM analysis reveals the growth of nano/micro sized cavities, pores, pits, voids and cracks for the ion dose ranging from 60 × 1013 to 70 × 1015 ions/cm2. However, at maximum ion dose of 84 × 1016 ions/cm2 the granular morphology is observed. XRD analysis reveals that new phase of CuZnNi (200) is formed in the brass substrate after ion implantation. However, an anomalous trend in peak intensity, crystallite size, dislocation line density and induced stresses is observed in response to the implantation with various doses. The increase in ion dose causes to decrease the Yield Stress (YS), Ultimate Tensile Strength (UTS) and hardness. However, for the maximum ion dose the highest values of these mechanical properties are achieved. The variations in the mechanical properties are correlated with surface and crystallographical changes of ion implanted brass.

Investigation of 500 keV Si ion induced surface structuring of Ni and Ti for enhancement of field emission properties

“…The increasing ion fluence up to 42.4 × 10 13 ions/cm 2 in Figure 2D increases the number of incident ions in a localised region and the agglomerated particulates start melting because of high surface temperature due to the greater kinetic energy transfer by incoming ions and creates wrinkels as shown in the inset of Figure 2D. The formation of the sputtered pattern over the ion irradiated Ni at the highest ion fluence of 65.8 × 10 13 ions/cm 2 in Figure 2E is attributed to collisional sputtering which occurs due to the nuclear elastic collisions via direct atomic displacements by keV ions 28 . Due to this higher energy transformation, the volume of material expands rapidly and a rise in the temperature takes place in the peripheries of the ion‐irradiated zone.…”

“…The increasing ion fluence increases the number of incident ions in a localised region and the agglomerated particulates start melting because of high surface temperature due to the greater kinetic energy transfer by incoming ions. Due to this thermal annealing, the smaller grains will merge together to form a large size grain, and it will cause an increase in the crystallite size 28 …”

Study of the effects of Ni+ ion implantation on morphology, structure, hardness, and electrical conductivity of brass

“…Charging and intense ion beam played a key role for deformation of brass surface in different structural morphology. 19 Such dispersion of brass surface by ion bombardment took it into the formation of flower like structure. 20 In Figure 2C, in transferring from 1.9 × 10 14 to 4.8 × 10 14 ions cm −2 , the flower-like structure disappeared into damaged lattice site in pores and craters.…”

Impact of variable energy hydrogen ions on structural and mechanical properties of Zircaloy-4

“…The track of PKAs is then heated to a high temperature for a short time (10 −8 s) which causes a thermal spike in the vicinity of point defects [21]. The rise of localized temperature might facilitates the annihilation of some of the defects [23,24]. The defects that survive in this process are present in the material in the form of vacancies and interstitials and their clusters.…”