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Abstract-Atomic force microscopy methods are used to study calcium phosphate coatings that are formed on surfaces of various materials, which are used in medicine, by radio frequency magnetron sputtering of a hydroxyapatite target. The roughness parameters and values of the surface potentials of metal, polymer, and hybrid substrates are determined in a semicontact regime. Calcium phosphate coatings increase the roughness of surfaces of polymer and metal materials, thus presenting a stimu lating factor for the attachment and proliferation of osteogenic cells. Using the Kelvin method, it is shown that calcium phosphate coatings change the surface potential of substrates.

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669.15`24Electron diffraction microscopy of thin foils is used to study the defect substructure of armco iron subjected to equal channel angular extrusion at room temperature, using the processing route A. The morphology of the defect substructure is shown to be substantially affected by the section plane of the billets. The results obtained suggest that the evolution of the defect substructure of the material subjected to equal channel angular extrusion is clearly revealed only by examining no fewer than three mutually perpendicular section planes.

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The paper reports changes in strain fields on welded sample surfaces from commercial pure titanium, joined by both laser beam welding (LBW) and gas tungsten arc welding (GTAW) procedures, under uniaxial tensile loads. Their dynamics were investigated by the digital image correlation method using a ‘Vic-3D’ optical system. In addition, stress-strain curves were drawn in both σeng-εeng and σtrue-εtrue coordinates. It was shown that the laser welded sample was characterized by a higher ultimate tensile strength to yield point ratio than the as-received one. The GTAW sample fractured under much less stresses than the LBW one.