Effect of indium addition on microstructural, mechanical and oxidation properties of suction cast Nb–Si eutectic alloy

Abstract

The paper reports effect of small ternary addition of In on the microstructure, mechanical property and oxidation behaviour of a near eutectic suction cast Nb-19?1 at-%Si-1?5 at-%In alloy. The observed microstructure consists of a combination of two kinds of lamellar structure. They are metal-intermetallic combinations of Nb ss -b-Nb 5 Si 3 and Nb ss -a-Nb 5 Si 3 respectively having 40-60 nm lamellar spacings. The alloy gives compressive strength of 3 GPa and engineering strain of y3% at room temperature. The composite structure also exhibits a large improvement in oxidation resistance at high temperature (1000uC).

Five decades of research on the development of eutectic as engineering materials

“…However, these alloys have low room temperature ductility and fracture toughness. In a series of work, Kashyap et al explored ternary addition (Ga, Al, In, Mg, and Ni) in the eutectic composition that can reduce interlamellar spacing and modify the morphologies [207][208][209][210][211]. The submicron spacing results in an improvement in ductility and fracture toughness (Fig.…”

“…The Al addition results in fine precipitates, which improves room temperature and high-temperature strength. The addition of In modifies the phases present in the eutectic microstructure and results in high strength, good ductility, and oxidation resistance [211]. The other alloying additions such as Mg and Ni refines eutectic and form non-equilibrium phases, resulting in improved mechanical properties and oxidation.…”

Influence of vacancy on structural and elastic properties of NbSi 2 from first-principles calculations

“…[1][2][3][4][5][6]. Early works have focused on the mechanical properties of Nb\ \Si based superalloys [7][8][9][10][11][12][13]. For example, the calculated bulk modulus and shear modulus of Nb 5 Si 3 are 193 GPa and 125 GPa [14], and the bulk modulus and shear modulus of Nb 3 Si are 183 GPa and 72 GPa [15], respectively.…”

Influences of Vacancy Concentration and Al Substitution on Structural, Electronic, and Elastic Properties of Nb5Si3 from First‐Principles Calculations

“…Generally speaking, the elastic and plastic properties of a material can be judged by hardness. The hardness of the vacancy is calculated by hardness model [30] H V ¼ 2ðk 2 GÞ 0.585 À 3 (7) where k represents the shear modulus versus bulk modulus and G is the shear modulus, respectively. Debye temperature is calculated by means of average sound velocity, as shown [31]…”

“…[3][4][5][6] In recent years, the use of alloying and optimizing processing techniques has improved mechanical properties at room temperature. Kashyap et al [7][8][9] studied that the addition of In, Al, and Mg significantly improved the mechanical properties and oxidant properties of Nb-Si alloy. In addition, theoretical studies show the bulk modulus/shear modulus (B/G) ratio of 1.54 [10] of Nb 5 Si 3 alloy, meaning that this alloy is a brittle material.…”