Technology of Ti-Al-Nb Obtaining by Use of Spark Plasma Sintering Method

Abstract

This method grants effective control of the porosity of the sintering materials and ability to obtain compactly packed samples, where simple pressing is not feasible. Spark plasma sintering is one of the probable methods that could lead to larger energy efficiency in material manufacturing. Upon use of SPS, there is no need to “pre-heat” the material by use of pressure or additional use of connecting agents or components. Manufacture of the components is being finished at the instant. Initial microstructure of the powder is being saved. Besides, with use of analyzing method, it is possible to obtain material of the new type, ones that are have resistance to heat. Use of SPS technology could imply lesser time of sintering for highly packed specimens. Decrease of time implies decrease of microstructural changes as a result of diffusion controlled phase changes. Taking into account what has been mentioned above, choosing the best suitable regime for Ti-Al-Nb proposes a variety of intermetallic junctions and could be used for creation of alloys with different physical-mechanical properties. This study concentrates on optimal regime of obtaining intermetallic junction based on Ti-Al-Nb with use of spark plasma sintering.

Powder Composition Structurization of the Ti-25Al-25Nb (at.%) System upon Mechanical Activation and Subsequent Spark Plasma Sintering

“…This method makes it possible to form complex coordination compounds and multicomponent compositions of various dispersion with increased operational properties in a small amount of time and one stage [9,10]. The use of pre-mechanical activation (MA) of reaction mixtures in high-energy mills before SPS allows the formation of a more uniform fine-grained structure of synthesis products with increased content of dissolved elements (above the values of limiting solubility) and activates less thermodynamically preferable reactions, thereby providing the ability to control the phase composition of composite powders [11][12][13][14]. In addition, it is known [15] that, during sintering, the boundary diffusion coefficient is determined by the surface layer structure, and not by the refractory core of the particles, as a result of which, after MA of the powder mixture, there is a significant decrease in temperature of their consolidation, grain growth and bridges due to high surface diffusion.…”