Experimental Studies on Microscopic and Mechanical Properties of Nimonic 90 Superalloy Synthesized Using Powder Metallurgy

Abstract

Application of nickel-based superalloys is gradually rising in many sectors such as aerospace, automotive and marine industries due to their exceptional thermo-mechanical properties. Superalloys are predominantly fabricated by casting process. The pursuit of customized materials possessing with exceptional properties has driven the scholars to investigate the possibility of powder metallurgy for preparing them and assess their appropriateness to produce gas turbine components. This study focuses on the use of powder metallurgy approach for synthesizing Nimonic 90 superalloy. Physical properties such as density, microhardness and macrohardness are determined to validate with the standard sample. Mechanical properties like tensile strength and compressive strength are measured and analyzed. Dry sliding wear test is done to study the wear characteristics. Density and hardness of the material are close to that of standard alloy, which is due to the appropriate selection of sintering temperature and stay time. Measured values for the ultimate tensile strength, 0.2% offset yield strength and percentage of elongation are approximately 900 MPa, 386 MPa and 52%, respectively. In microscopic study, it is observed that the material has γ/γ’ phase because of precipitation hardening and solid solution strengthening. Findings establish the fundamental basis for near-net-shape manufacturing by powder metallurgy.