Análise estrutural e tribológica do efeito de adição de carbono na liga ALNiTiV

Abstract

High-entropy alloys (HEAs) are composed of four or more principal elements, each with a concentration between 5% and 35%, resulting in a significantly higher entropy effect compared to conventional alloys. These alloys have shown promising potential for a wide range of applications, exhibiting exceptional properties such as high hardness, superior mechanical strength, excellent high-temperature performance, good ductility, and fracture toughness. The present study aimed to analyze the structural and tribological effects of adding 2% carbon to the high-entropy alloy Al₁₇Ni₃₄Ti₁₇V₃₂. For this purpose, both alloys, with and without carbon, were processed by arc melting in a furnace with controlled atmosphere using high-purity elements. The alloys were characterized by reciprocating linear sliding abrasive wear tests and structural analysis using optical microscopy, X-ray diffraction (XRD), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), and hardness testing. The results revealed the formation of titanium and vanadium carbides, ranging from 5 to 10 μm in size, distributed throughout the structure of the Al17Ni34Ti17V32 alloy. This addition of carbon increased the hardness from 472.9 ± 2.6 HV (Al17Ni34Ti17V32) to 556.7 ± 34.5 HV (Al17Ni34Ti17V32+2%C), which enhanced its resistance to abrasive wear.