Anisotropic Mechanical Properties of Graphene Nanosheet–Reinforced Powder Metallurgy Nickel‐Based Superalloy

Abstract

Nickel-based superalloys [1] are key materials in airplane and turbine disks due to their outstanding properties such as high tensile strength and excellent creep deformation resistance. With the increasing requirements of the modern aerospace industry on the performance of materials, traditional nickel alloys are gradually unable to meet the demands of high properties. Thus, selecting the nanoreinforcement phase to construct metal matrix composites (MMCs) is one of the simple and easy ways to improve the performance of materials. [2] The MMC materials [3] not only possess excellent performance of the metal matrix, but also combine several advantages such as high tensile properties, good thermal expansion, low thermal expansion coefficient, and good wear resistance originating from the reinforcement phase. Graphene [4,5] and its related derivative materials (such as graphene oxide (GO), [6] multilayer graphene, [7] graphene nanosheets (GNS), [8] graphene nanoflakes (GNFs) [9]) are a series of 2D materials with unique layered hexagonal honeycomb structure. It is considered to be an ideal reinforcement phase for MMCs due to its unique structure and extraordinary electronic, mechanical, and thermal properties. In the reported literature, graphene-reinforced MMCs (Al, [10] Cu, [11] Ti, [9,12] Ni, [13,14] etc.) have been successfully prepared by hot isostatic pressing (HIP), [15] spark plasma sintering (SPS), [16] laser additive manufacturing (LAM), [17] and so on. These graphene-reinforced MMCs show impressive strength and toughness. A small amount of added graphene can greatly improve the mechanical properties of the MMCs, such as tensile properties and wear resistance. Regarding the mechanical properties of graphene-reinforced MMCs, the uniform graphene dispersion, the bonding interface between graphene and the matrix, and the arrangement of graphene in the matrix are still the main factors influencing the large-scale applications of graphene-reinforced MMCs. [18] The dispersion and arrangement of graphene in the matrix are the basic factors affecting the MMCs. The poor dispersion and disordered arrangement will result in agglomeration of graphene and weakly bonded interfaces between reinforcement and matrix phases. These defects lead to crack initiation and propagation, [19] which ultimately weakens the reinforcing effect of graphene. Therefore, improving the properties of MMCs by structural design to change the spatial distribution pattern of the micro-/ nanograde reinforcement phase in the matrix has become urgent in current research.

Microstructure and Mechanical Properties of Spark Plasma-Sintered Graphene-Reinforced Inconel 738 Low Carbon Superalloy

“…It has been reported that the perfectly constructed graphene nanoparticles are chemically stable and mostly do not react with metals (chemically). [30] It was observed that the grains interlocked through the grain boundaries, which suggests that the grains were closely packed. Hence, strong metallurgical bonding exists between the metallic elements and reinforcement (graphene).…”

Structural and Functional Adaptive Artificial Bone: Materials, Fabrications, and Properties

“…In particular, graphene nanosheet has excellent mechanical properties (modulus: ≈1 YPa, strength: ≈130 GPa), huge specific surface area (600–10 000) and very large width to thickness ratio (≈100), making them possessing the highest strength, best toughness and largest specific surface area found so far. [ 135,136 ] Jang et al. developed a biomimic biocomposite complexing by GO/crystalline HAP, and the results showed that the protein adhesion ability was better than pure HAP because GO had a high protein adsorption capacity by surface reactors.…”

Hot Deformation Behavior of a Powder Metallurgy Superalloy with High γ′ Content

“…Thus, the constitutive equation at a strain of 0.4 was established as Equation (11), by substituting A, α, n, and Q into Equation (3) ε : ¼ 1.51  10 32 ½sinhð0.00993σÞ 3.1873 expðÀ894260=RTÞ (11)…”

“…[5] The development of P/M superalloys includes Rene 95, [6] EP741NP, [7] N18, [8] Rene 88DT, [9] RR1000, [10] and FGH96. [11] EP741NP, a P/M superalloy manufactured by direct HIP, is widely used in turbine engines. [7,[12][13][14] The main disadvantage of superalloys made by HIP is the formation of a prior particle boundary (PPB) containing oxides, carbides, and γ 0 , which is detrimental to the material's mechanical properties.…”

“…[ 5 ] The development of P/M superalloys includes Rene 95, [ 6 ] EP741NP, [ 7 ] N18, [ 8 ] Rene 88DT, [ 9 ] RR1000, [ 10 ] and FGH96. [ 11 ]…”