Effect of Mechanical Milling on the Mechanical, Dry Sliding Wear, and Impact Response of Sintered Nickel Based Superalloy

Abstract

In this study, effect of mechanical milling on the mechanical, dry sliding wear and impact response of spark plasma sintered Ni-17Cr6.5Co1.2Mo6Al4W7.6Ta superalloy has been investigated. Two nickel-based superalloy were sintered, firstly in their as-received elemental particle sizes, while the matrix, nickel of the second alloy, was milled to 10 h prior blending with other elements and subsequent sintering. The impact response was explored using computational modelling approach via finite element analysis, Abaqus CAE/2019. Results show that the superalloy with the milled nickel powder exhibited better mechanical properties such hardness, elastic modulus, elastic and plastic strain from impact response than the superalloys with unmilled nickel. Sliding wear tests under dry sliding conditions at three different loads of 20, 25 and 30 N revealed that the superalloy with the milled nickel have lower wear rate when compared to the other with unmilled nickel. It was observed that the wear rate reduced unexpectedly at the applied load of 30 N which may be attributed to the continuous formation of tribo-oxide layer from retained wear debris on worn surface.