HOSSON , J.th.m. De

A modified blister test has been developed based on helium ion implantation into selected areas of the metal substrate prior to the coating deposition. After a post-deposition thermal annealing, blisters are formed by agglomeration of the implanted gas at the ceramic–metal interface. This method can be used to control the pressure in the...

Surface effects on (1 1 1) copper single crystal surfaces after 30 keV helium implantation up to 2.4 × 1016 ions cm−2 and subsequent annealing at 973 K have been studied using scanning electron and confocal microscopy. Since one aim of the work was to develop a method of studying the adhesion of surface coatings, the implantations were...

Positron annihilation spectroscopy (PAS) has proven to be a very useful technique for, e.g., the study of defects in materials and the characterization of polymer free-volume. Positron lifetime, Doppler broadening of the annihilation radiation (characterized by the so-called S parameter) and angular correlation of annihilation radiation (ACAR)...

In this paper we present the first combined Positron Beam Analysis (PBA) and Environmental Scanning Electron Microscopy (ESEM) adhesion study on thin chromium nitride (CrNx) coatings. Both techniques are combined with a 4-point bending stage. PBA monitors the creation of open volume in the ceramic/metal interface prior to delamination while...

In this work we have studied the adhesion of PVD amorphous hydrogenated carbon (a-C:H) thin coatings (<200 nm) on crystalline silicon by means of positron beam analysis (PBA). PBA allows the study of the a-C:H layer and the interface by monitoring changes on the Doppler broadening parameters S and W. Depending on the deposition condition, using...

The porosity in particle reinforced sol-gel coatings has been studied. Silica particles (Ludox-TM40) are introduced into methyl silicate coatings to increase the hardness, the elastic modulus and the fracture toughness. The methyl silicate has a relatively low density (about 1.2 g/cm2), while the silica particles are known to be porous....

Two sets of ZrO2 thin films have been prepared at room temperature by ion beam induced chemical vapour deposition and subsequently annealed up to 1323 K. The two sets of samples have been prepared by using either O2+ or mixtures of (O2++Ar+) ions for the decomposition of a volatile metallorganic precursor of zirconium. The structure and...