Mechanical and tribological studies of sintered nickel-based ternary alloys

Abstract

Purpose During the operation of nickel-based alloys as blades and discs in turbines, the sliding activity between metallic surfaces is subjected to structural and compositional changes. In as much as friction and wear are influenced by interacting surfaces, it is necessary to investigate these effects. This study aims to understand better the mechanical and tribological characteristics of Ni-17Cr-10X (X = Mo, W, Ta) ternary alloy systems developed via spark plasma sintering (SPS) technique. Design/methodology/approach Nickel-based ternary alloys were fabricated via SPS technique at 50 MPa, 1100 °C, 100 °C/min and a dwell time of 10 mins. Scanning electron microscopy, X-Ray diffraction, energy dispersive X-ray spectroscopy, nanoindentation techniques and tribometer were used to assess the microstructure, phase composition, elemental dispersion, mechanical and tribological characteristics of the sintered nickel-based alloys. Findings The outcome of the investigation showed that the Ni-17Cr10Mo alloy exhibited the highest indentation hardness value of 8045 MPa, elastic modulus value of 386 GPa and wear resistance. At the same time, Ni-17Cr10W possessed the least mechanical and wear properties. Originality/value It can be shown that the SPS technique is efficient in the development of nickel-based alloys with good elemental distribution and without defects such as segregation of alloying elements, non-metallic inclusions. This is evident from the scanning electron microscopy micrographs.

Nanoindentation and Structural Analysis of Sintered TiAl(100−x)-xTaN Composites at Room Temperature

“…The elasticity, plasticity, and deformability characteristics reflect the indentation resistance capabilities of sintered materials, as shown by the regions of loading and unloading curves covered in Figure 5 a. This is schematically defined in Figure 7 f, showing that the regions covered by the loading and vertical lines constitute the total deformation energy ( W t ) exhibited by the material, while the region between the loading and unloading curve denotes the plastic deformation energy ( W p ) exhibited by the material [ 31 , 59 ]. It can be seen in Figure 5 a that the TiAl exhibited the highest deformation energy and the lowest was exhibited by the TiAl−8 wt.% TaN composite, which is corroborated by the trend observed in Figure 7 d.…”

“…A novel fabrication method for TiAl alloys and composites is the Spark Plasma Sintering (SPS) technique. SPS offers the ability to fabricate alloys and composites with high densification of constituent powders within a relatively short processing time [ 29 , 30 ] and lower temperature, and also prevents impurities from reacting with the component [ 31 , 32 , 33 , 34 ].…”

“…Consequently, the nanoindentation technique offers distinct advantages compared to conventional indentation methods [ 35 ]. This technique has been used by researchers [ 31 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 ] to shed light on various mechanical property responses of materials. It offers the unique advantage of evaluating materials’ properties without compromising the structure of a material.…”

Sintering of nanocrystalline materials: Sintering parameters

“… Localized deformation at contact points, as shown in Fig. 3 (ii), and The bulk deformation of particles [ [42] , [43] , [44] ], as illustrated in Fig. 3 (iii).…”

Spark Plasma Sintering of TaN/TiAl Composites: Microstructure and Microhardness Study

“…Other merits, such as low energy consumption, attainment of a homogenous product, to name a few, are attainable through SPS adoption [23]. During fabrication using the SPS route, the consolidation is done by using direct heating through the joule effect within the material from pulsed DC and deformation of constituent powders through the applied pressure [24][25][26][27]. Herein, TaN/TiAl matrix composites were developed via spark plasma sintering technique with varied addition of TaN from 2-8 wt.%.…”