Interdifusão nos aluminetos de metais refratários (Mo, Nb, Ta e V) e determinação de grandezas cinéticas

Abstract

Studying diffusion is essential in understanding various physicochemical and mechanical properties of different materials (creep, oxidation, grain growth, among others), it controls phase transformations in the solid state. These diffusional processes are exploited in the manufacture of various products destined for various industrial sectors. As an example, Ni-based superalloys are the class of materials most used at high temperatures due to their ability to maintain good mechanical stability with relatively high oxidation resistance. In order to increase its chemical resistance, a method that can be used is by means of a superficial treatment of aluminization using the pack cementation technique, which also can be applied at the same time for refractory element with great potential for utilization at high temperatures applications. In the present work, the pack cementation was explored to determine the kinetics data in M-Al systems (M = Nb, Mo, V e Ta). This work consists mainly of the calculation of the interdiffusion coefficients for the intermetallic compounds of the refractory elements molybdenum (Mo), niobium (Nb), tantalum (Ta) and vanadium (V) through the pack cementation process to contribute with data that will be investigated in a systematic way for the first time.