Effect of nickel powder particle size on the microstructure and thermophysical properties of spark plasma sintered NiCrCoAlTiW-Ta superalloy

Abstract

The spark plasma sintering technique (SPS) was used to consolidate admixed elemental powder in order to fabricate NiCrCoAlTiW-Ta superalloy. Nickel which is the key element that formed the matrix powder particle size was varied in the range of 3-44, 45-106 and 106-150 μm. The effect of varying the starting powder particle size, on the formation of intermetallic phases was investigated. Also, important thermophysical properties in the development of superalloys for high temperature applications were investigated by using laser flash machine, in the range of 100-800 °C. The constituents of the microstructure for the sintered alloy includes, the gamma (γ) matrix phase (Ni), precipitated intermetallic gamma prime (γ’) phase Ni3(Al, Ti) and the precipitated solid solution strengthening elements (Cr and W). There was an increase in the density with decreasing powder particle size. Also, the averave grain size increased with increasing powder particle size. The thermophysical properties obtained, which include thermal conductivity and diffusivity increase with increasing temperature. Non-linear behaviour and inflection points were observed as the temperature increases due to short range order and disorder phenomenon which is associated with superalloys. The powder particle size has little or no significant effect of the thermophysical behaviour as the pattern observed were almost the same.

Optimization of process parameters for the development of Ni–Al-Ti-Mn-Co-Fe–Cr high entropy alloy system via spark plasma sintering

“…The aviation, automobile, marine, and chemical processing industries demand fully dense, highstrength, tough materials for high-temperature applications and lightweight materials that can withstand stress. Metallic alloys such as aluminium, titanium, and nickel-based superalloys have been employed to meet this requirement [1,2]. However, these alloys are characterized by high-density characteristics requiring a high mechanical load to operate.…”

“…This bond has generated outstanding properties at an extreme temperature and good strength that could effectively compete with superalloys and ceramics. The NiAl-based alloy has shown superior thermomechanical properties, excellent corrosion, wear, and creep resistance compared to the conventional nickel-based superalloys [1][2][3][4][5][6]. Nickel-aluminide is an intermetallic compound containing aluminium and nickel and has been the focus of recent researchers.…”

The effects of powder size and sintering temperature on the microstructure and properties of modified MA6000 alloy produced by spark plasma sintering

“…The material becomes pliable from the heat, leading to plastic deformation followed by a combination of diffusion and plastic deformation resulting in a high degree of solidification (over 99% theoretical density) of the powder. The advantages, disadvantages, and mechanisms of SPS technology have been reported [13][14][15]. The effects of sintering temperature, heating rate, initial powder size, and other fabrication conditions have been investigated [13][14][15][16][17].…”

“…The advantages, disadvantages, and mechanisms of SPS technology have been reported [13][14][15]. The effects of sintering temperature, heating rate, initial powder size, and other fabrication conditions have been investigated [13][14][15][16][17]. Nevertheless, understanding the impact of the SPS conditions on MA6000 alloy is still in its preliminary stages.…”

Spark plasma sintering of ZrO2 reinforced Ni-Cr alloy: Microstructure and mechanical behavior

“…2 The ability of nickel-based alloys to maintain high strength at elevated temperatures, high resistance to wear, corrosion, and fatigue; and high toughness are distinctive attributes which increase their demand in the combustion chambers of aircraft, and power generation. [3][4][5][6][7][8] Nickel-based alloys with a chromium content of 15-30% weight fractions are commonly utilized in land turbine and aircraft turbine engines where high temperatures and strong mechanical loads are encountered. This is due to their ability to maintain their strength at high-temperature, and also display good resistance to corrosion and oxidation at high-temperature.…”