Positron Annihilation and Complementary Studies of Copper Sandblasted with Alumina Particles at Different Pressures

Horodek, P.; Siemek, Krzysztof; Dryzek, Jerzy; Wróbel, Mirosław

doi:10.3390/ma10121343

Cited by 11 publications

(7 citation statements)

References 37 publications

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“…This depth coincidences with the depth of subsurface generated during dry sliding or sandblasting. In copper it is about 140-800 lm as it was shown in our recent studies [3]. Thus, due to the skin effect conducting electrons are pushed to flow near the surface of a wire or a bar, but in this region they scatter at additional crystalline defects which may be created during manufacturing.…”

Section: Introductionmentioning

confidence: 72%

Positron Annihilation Studies of the Near-Surface Regions of Niobium before and after Wear Treatment

Dryzek

Horodek

2017

Tribol Lett

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The positron annihilation studies of well-annealed niobium samples after dry sliding or sandblasting are reported. These treatments modify surface and subsurface regions introducing crystalline defects, which are extended beneath the surface of the sample at a depth of about 140 lm for the highest applied load of 50 N. These defects can be identified as dislocations with jogs or vacancies near dislocations. The obtained depth profile of mean positron lifetime reflects the defect depth distribution and exhibits the characteristic plateau near the worn surface, which disappears when lowering of the applied load. A similar depth profile was obtained also for niobium samples after sandblasting. Slow positron beam studies revealed that at the surface of the samples after dry sliding or other treatments some defects that localize positrons are present. Additionally, a large value of positron diffusion length of about 266(33) nm was found for well annealed niobium.

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Section: Introductionmentioning

confidence: 72%

Positron Annihilation Studies of the Near-Surface Regions of Niobium before and after Wear Treatment

Dryzek

Horodek

2017

Tribol Lett

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“…Bismuth -Advanced Applications and Defects Characterization zone depth generated during, e.g. machining or sandblasting, in copper it is about 140-800 μm as it was reported, see Ref [8]. The skin effect causes that electrons flow mainly near the surface of the conductor, but in this region, they can scatter at crystalline defects which were created during manufacturing of wires or other devices.…”

Section: Introductionmentioning

confidence: 88%

Application of Positron Annihilation Spectroscopy Studies of Bismuth and Subsurface Zone Induced by Sliding

Dryzek¹

2018

Bismuth - Advanced Applications and Defects Characterization

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The positron annihilation, experimental and theoretical results obtained for bismuth are presented, mainly concerning the open volume defects created during compression and dry sliding. Positron lifetime in vacancy clusters increases with the size of the cluster; however, it saturates at the value of about 0.42 ns already for six vacancies in a cluster. Similar values were resolved in the positron lifetime spectra of bismuth samples exposed to dry sliding. Detection of the subsurface zone in bismuth exposed to dry sliding reveals exponential decay of vacancy clusters concentration with the depth increase from the worn surface. The high strain of about 70% was evaluated in the layer adjoined the worn surface The temperature of recrystallization obtained from the isochronal measurements of annihilation line shape parameter was equal about 90°C, and the activation energy for grain migration is about 0.84 ± 0.11 eV.

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“…The etching does not introduce additional defects. The Positron Anihillation Spectrometry PAS measurements combined with etching experiments were chosen due to the fact that previously it gave interesting results in the field of defect studies for plastically deformed materials [ 31 , 32 , 33 , 34 ].…”

Section: Methodsmentioning

confidence: 99%

Consequences of Different Mechanical Surface Preparation of Ni-Base Alloys during High Temperature Oxidation

et al. 2020

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The influence of surface roughness on its high temperature oxidation for an Ni-base superalloy was studied using laser profilometry, atomic force microscopy, mass change measurements, glow-discharge optical emission spectrometry, scanning electron microscopy, X-ray diffraction, and positron annihilation methods. The isothermal and cyclic air oxidation tests were performed at 1000 °C and showed dependence of oxidation behavior on surface roughness. Smoother surfaces oxidation resulted in the formation of a multilayered oxide scale consisting of NiO, Cr2O3, and internally oxidized Al2O3 while a rougher surface formed protective Al2O3 scale. The factors responsible for different oxidation behaviors were determined as higher concentration of vacancies and increased residual stresses in the near-surface region of studied alloys.

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Positron Annihilation and Complementary Studies of Copper Sandblasted with Alumina Particles at Different Pressures

Cited by 11 publications

References 37 publications

Positron Annihilation Studies of the Near-Surface Regions of Niobium before and after Wear Treatment

Positron Annihilation Studies of the Near-Surface Regions of Niobium before and after Wear Treatment

Application of Positron Annihilation Spectroscopy Studies of Bismuth and Subsurface Zone Induced by Sliding

Consequences of Different Mechanical Surface Preparation of Ni-Base Alloys during High Temperature Oxidation

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