EFFECT OF THE TECHNOLOGICAL PARAMETERS ON THE FEATURES OF STRUCTURE AND MECHANICAL PROPERTIES OF MULTI-COMPONENT HIGH-TEMPERATURE NIOBIUM BASED ALLOY

Abstract

The  results for investigations of the efect of  production technology and  main technological parameters of multicomponent heat-resistant 57 Nb–10 Cr–5 Al–21 Ti–7 Mo (%, at.) alloy, produced by powder metallurgy methods from a mixture of elementary metal powders of appropriate component composition on the structural features and mechanical properties are presented in the article. The technological scheme of  material manufacturing included consolidation of powder mixtures, part of which was subjected to mechanical activation in a planetary mill, and their subsequent hot forging. Some of the hot-forged specimens were annealed in a vacuum furnace at a temperature of 1600 °C. As a result of the research, it was established that the structure of hot-forged materials has a significantly heterogeneous nature and consists of a matrix solid phase based on the Nb–Mo system and evenly distributed grains of the intermetallic phase based on the Ti-Al system in the presence of marked anisotropy. The gradient nature of Al and Nb distribution in titanium grains after hot forging was established. Annealing at 1600 °C leads to almost complete homogenization of the alloy with the formation of a single-phase bcc structure and a change in the morphology of the grain structure. The highest level of mechanical properties at room temperature and at 600 °С are noted for the materials obtained by hot forging from mixtures, milled for 30–60 minutes, while at 1000 °C the yield point of the alloy annealed at 1600 °C already exceeds the value of s_0,2 of hot-forged alloys that were not annealed, and is at the level of a cast alloy of a similar composition.