PHASE FORMATION IN THE DIFFUSION ZONE OF TITANIUM − PLATINUM

Abstract

Formulation of the problem. The technology of different titanium-platinum materials interconnection by means of diffusion welding in vacuum is presented. The diagram of Ti−Pt state was analyzed and the main types of components interaction were determined. It was found that formation of the welded joint through the growth of the diffusion zone in the titanium by the successive growth of intermetal Ti₃Pt, TiPt, TiPt₃ balls as well as zones of solid solutions. Materials and methodology. The microstructure analysis, microhardness measurement, phase composition definition on the DRON-1.5 allowed to determine the phase composition of platinum − titanium compound and the width of each zone. Results. Welding parameters influence weld quality. It is possible to change the overall width of the diffusion zone as well as that of individual joints by changing the welding cycle time. Thus, the determination of the mechanical properties of the joint obtained by diffusion welding in vacuum, allows setting the optimum operating time. Scientific novelty. It was found that the phase composition and length of intermetal zones depend on the welding parameters and influence the quality of the titanium − platinum joint achieved by diffusion welding under vacuum. Practical significance. Based on experimental investigations, a diffusion welding procedure in vacuum is recommended: T = 1 138 K, P = 6, 37 MPa, τ = 1 800 s.