Defects in hard coatings studied by positron annihilation spectroscopy and x‐ray diffraction

1992 ◽  
Vol 10 (1) ◽  
pp. 193-207 ◽  
Author(s):  
James P. Schaffer ◽  
Anthony J. Perry ◽  
Jean Brunner
Keyword(s):  
Positron Annihilation ◽  
Positron Annihilation Spectroscopy ◽  
Hard Coatings ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Investigation Of Helium Implanted Fe–Cr Alloys By Means Of X–Ray Diffraction And Positron Annihilation Spectroscopy

2015 ◽  
Vol 66 (6) ◽  
pp. 334-338
Author(s):  
Patrik Novák ◽  
Aleksandr Gokhman ◽  
Edmund Dobročka ◽  
Jozef Bokor ◽  
Stanislav Pecko
Keyword(s):  
Positron Annihilation ◽  
Domain Size ◽  
Surface Region ◽  
Grazing Incidence ◽  
Positron Annihilation Spectroscopy ◽  
Lattice Parameter ◽  
Implantation Dose ◽  
X Ray Diffraction ◽  
Coherent Domain Size ◽  
X Ray

Abstract X-ray diffraction (XRD) and positron annihilation spectroscopy (PAS) have been used for the characterization of the two binary alloys Fe-Cr with Cr content 2.36 and 8.39 wt%. The influence of ion implantation on these alloys was studied. Different implantation doses of helium, up to 0.5 C/cm2, were used to simulate neutron-induced damage in a sub-surface region. To characterize the damage, a lattice parameter, coherent domain size, residual stress and a crystallographic texture have been studied by grazing incidence X-ray diffraction (GIXRD). It was found out that these parameters showed a similar dependence on the implantation dose as the positron lifetime determined by positron annihilation spectroscopy.

Macroscopic Fracture Behaviour of CrN Hard Coatings Evaluated by X-Ray Diffraction Coupled with Four-Point Bending

2013 ◽  
Vol 768-769 ◽  
pp. 272-279
Author(s):  
Mario Stefenelli ◽  
Angelika Riedl ◽  
Juraj Todt ◽  
Matthias Bartosik ◽  
Rostislav Daniel ◽  
...  
Keyword(s):  
Fracture Stress ◽  
Fracture Behavior ◽  
Fracture Behaviour ◽  
Hard Coatings ◽  
Relevant Parameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Four Point Bending ◽  
Macroscopic Fracture ◽  
Crn Coatings

Fracture behavior of hard nanocrystalline coatings decisively influences the lifetime and performance of coated tools. In this work, residual stresses in as-deposited and annealed CrN coatings deposited at 350 °C using bias voltages of −40 V and −120 V were evaluated using synchrotron X-ray diffraction coupled with four-point bending. The stress development during the bending experiments was used to analyse fracture properties of the coatings. The results indicate that an annealing at 550 °C does not deteriorate the fracture behavior of the coatings prepared using −40 V bias. In the case of −120 V bias coatings, the residual stress relaxation after the thermal treatment is accompanied by a fracture strain decrease and a fracture stress increase. The as-deposited and annealed CrN coatings deposited using −120 V bias exhibit significantly large fracture strains in comparison with −40 V samples. Finally the results document that the fracture stress may not be the only relevant parameter when comparing different coating systems. Also the strain at fracture can be considered as significant indicator of the coating fracture response. Methodologically, the results indicate that in-situ X-ray diffraction coupled with four point bending can be effectively used to evaluate macroscopic fracture behaviour of hard coatings.

Study of various types of diamonds by measurements of double crystal x‐ray diffraction and positron annihilation

1995 ◽  
Vol 78 (3) ◽  
pp. 1510-1513 ◽  
Author(s):  
S. Fujii ◽  
Y. Nishibayashi ◽  
S. Shikata ◽  
A. Uedono ◽  
S. Tanigawa
Keyword(s):  
Positron Annihilation ◽  
X Ray Diffraction ◽  
Double Crystal ◽  
X Ray

Hydrogen Interaction with Defects in ZnO

2012 ◽  
Vol 733 ◽  
pp. 228-231 ◽  
Author(s):  
František Lukáč ◽  
Jakub Čížek ◽  
Marián Vlček ◽  
Ivan Procházka ◽  
Martin Vlach ◽  
...  
Keyword(s):  
Subsurface Layer ◽  
Positron Annihilation Spectroscopy ◽  
Nuclear Reaction Analysis ◽  
X Ray Diffraction ◽  
High Concentration ◽  
X Ray ◽  
Low Concentrations ◽  
Hydrogen Interaction ◽  
Induced Stresses ◽  
Zno Crystal

In the present work hydrothermally grown ZnO single crystals were electrochemically charged with hydrogen. The influence of hydrogen on ZnO microstructure was investigated by positron annihilation spectroscopy (PAS) combined with X-ray diffraction (XRD) using synchrotron radiation. Hydrogen concentration in the samples was determined by nuclear reaction analysis (NRA). It was found that a high concentration of hydrogen can be introduced into ZnO by electrochemical loading. At low concentrations, absorbed hydrogen causes elastic volume expansion of ZnO crystal. At higher concentration, hydrogen-induced stresses exceed the yield stress in ZnO and plastic deformation of the crystal takes place leading to formation of a defected subsurface layer in the crystals.

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