Effect of Hydrogen Absorption on the Composition of the Amorphous Alloys Surface Layers

Hydrogen absorption leads to redistribution of the components of the surface layer of the amorphous alloy Fe73.8Si12.7B9.4Nb3.2Cu noncontact side, while the amorphous structure of this layer is preserved. The type of the micro-groups Fey Six changes in such a way that the ratio y: x decreases (to less than 1) and the chemical bond polarity decreases, as well. After degassing, the surface layer composition becomes similar to those before hydrogenation. The loss of the mechanical stability of the amorphous ribbon is accompanied by the formation of the micro-groups Fey Six with a decreased ratio of y: x.

Effects of heat treatment and welding process on superelastic behaviour and microstructure of micro electron beam welded NiTi

Medical devices with small dimensions made of superelastic NiTi become more popular, but joining these parts remains challenging. Since laser welding was found to be an option, electron beam welding seems to be an interesting alternative as it provides additional advantages due to the precise beam positioning and the high vacuum. Superelasticity is influenced by microstructure and surface layer composition that are mainly affected by welding process and by heat treatment and therefore will be investigated in the present paper.

Surface Layer Composition Change under Irreversible Conditions of Particle Beam Action

The simple isothermal problem is formulated to describe the composition of surface layer change during particle beam action. The finiteness of relaxation time for mass flux is taken into account. The analytical solutions for some limiting cases are presented. Numerical solution of total problem is carried out. It is shown that concentration distributions for reactants and for reaction product depend on relation between various physical scales.