Estudo das propriedades mecânicas de ligas Fe-Ni e Fe-Ni-Mo processadas por metalurgia do pó

Abstract

The products made of pure iron containing Ni greatly expanded the applications of sintered products , including the manufacture of parts that withstand high loads such as transmissions in cars . The equilibrium diagram of Fe-Ni alloys demonstrate the presence of α and FeNi3 phase , but the phase transformations require a satisfactory chemical homogenization obtained by conventional processes for production of alloys by elevation of the liquid components .The solid-phase sintering facilitates the formation of clusters , since the particles together without change of state, which implies regions whose chemical composition differs significantly from the overall composition . Thus , this paper aims to contribute to a study aimed at identifying phases in alloys Fe - Ni and Fe - Ni - Mo sintered at temperature of 1100 ° C and processed by high energy ball milling ( RBM ) in order to assess the following: interface formed between dissimilar elements , analyze the phenomena found in it and identify metallurgical characteristics after sintering contributing to increased hardness, microhardness , ultimate tensile strength and modulus of elasticity . The study shall determine the equilibrium diagram through Thermocalc software , diffraction , X-ray spectrometry and X-ray energy dispersive ( EDS ) , and the analysis of optical microscopy and scanning electron microscopy (SEM ) . The results showed the presence of stable phases as α (CCC) and metastable phase as FeNi (CFC austenite). The microscopic analysis also demonstrated heterogeneity with different percentages of Nickel and Iron along the samples.