Structure Formation, Chemical and Phase Composition in Compound from Noncorrosive Alloys

Abstract

By means of methods of scanning electron microscopy, microhardness, X-ray and electron microscope analysis were studied changes of structure, chemical and phase composition for gradient of oldering by silver solder joint «titanium alloy-stainless». There was demonstrated that owing to interdiffusion of chemical elements, containing in solder (Ag, Cu) and alloy PT3V (Ti, Al, V) is formed diffusion zone with structure of eutectoid type (α + Ti2(Ag, Cu) intermetallide) with microhardness characteristic with close to the basic metal PT3V. On the side of stainless 18Cr10NiTi is formed diffusion zone with following layers: solder layer Ag–Cu, with depleted copper layer, and particles of intermetallide TiAg; layer on the base of intermetallic compound Ti (CuFe); layer on the base of intermetallic compound Ti (FeNi); layer on the base of intermetallic compound Ti (Fe, Cr)2; layer from tertiary compounds Ti5Cr8Fe16 of variable solubility; layer of steel, enriched by chromium, with three phase structure α + γ + σ. Availability of intermetallic compounds in diffusion zone from the side of steel contributed to increasing of microhardness in comparison with the basic metal 18Cr10NiTi.