Effects of Multi-Phase Reinforcements on Microstructures, Mechanical and Tribological Properties of Cu/Ti3SiC2/C/BN/GNPs Nanocomposites Sintered by Vacuum Hot-Pressing and Hot Isostatic Pressing

Abstract

Cu/Ti 3 SiC 2 /C/BN/GNPs nanocomposites were prepared by vacuum hot-pressing (HP) sintering and hot isostatic pressing (HIP) sintering methods. Microstructures, mechanical and tribological properties of Cu/Ti 3 SiC 2 /C/BN/GNPs nanocomposites were investigated. Microstructures were examined by optical microscopy (OM), X-ray diffraction (XRD) and scanning electron microscope (SEM). Mechanical properties were determined by the relative density, micro-Vickers hardness, as well as tensile strength, compressive strength and shear strength. Tribological behavior of the Cu/Ti 3 SiC 2 /C/BN/GNPs composite against the GCr15 steel ring was evaluated using an M-2000 wear tester with high tangential sliding velocity. Results demonstrated that BN and graphene nano-platelets (GNPs) have an impact on the microstructures and mechanical properties of Cu/Ti 3 SiC 2 /C/BN/GNPs nanocomposites. Based on microstructures, and mechanical and tribological properties of Cu/Ti 3 SiC 2 /C/BN/GNP nanocomposites, strengthening, fracture and wear mechanisms for synergistic enhancement by multi-phase reinforcements were analyzed.Keywords: Cu/Ti 3 SiC 2 /C/BN/GNPs nanocomposites; hot isostatic pressing; microstructure; mechanical properties; wear BackgroundCopper matrix self-lubricating composites are widely used in many industrial applications, such as friction materials, bearings, bushes, brake pads/discs, electrical sliding contacts and fusion reactors, due to their excellent anti-friction, wear properties, good thermal, electrical conductivities, superior strength and ease of production [1-6]. As many reports have revealed, copper-graphite is one of the most often-used solid self-lubricating materials for graphite's lamellar structure [6], and copper-graphite composites have improved wear resistance, lower wear loss and friction coefficients than pure copper [7,8]. However, the main inadequacy of using graphite as self-lubricant is the unsatisfactory mechanical properties of the composites [9,10]. Due to the impressive thermal, electrical, mechanical and tribological properties, graphene is a promising reinforcement for copper matrix, and an increasing number of researches have examined Cu/graphene composites aiming to improve their mechanical and tribological properties [4,9,11]. The results reveal that the presence of graphene in matrix can not only improve the mechanical properties but also decrease both the friction coefficient and the wear rate of composites [12]. Nevertheless, the agglomeration of graphene nano-platelets (GNPs) and interfacial interactions significantly affect the strengthening efficiency of

Fabrication and Tribological Properties of Mesocarbon Microbead–Cu Friction Composites

“…Similar results have also been observed by Wang et al [12] and Chen et al [13]. In addition to graphite flakes, other kinds of graphite including expanded graphite and graphene nano-platelets have also been used to improve the wear resistance of Cu-based composites [12,14].…”

Microstructure and Mechanical Properties of Graphene-Reinforced Titanium Matrix/Nano-Hydroxyapatite Nanocomposites

“…Furthermore, thermodynamic analysis (∆G < 0) revealed that the reaction (Equation(7)) could be carried out when the temperature was higher than 720 °C [ 38 ]. Based on the result of the XRD ( Figure 4 ) and TEM ( Figure 8 ), Equations (8) and (9) are the chemical reactions in this study which have been inferred from literatures [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 ]. Additionally, Ti x P y detected by XRD ( Figure 4 ) was formed by the reaction between titanium and phosphorus which was derived from Equations (10) to (11).…”

“…Lanthanum and graphene nano-flakes (GNFs) were also added to the nanocomposites, which had acomposition of (54.3Ti-12.2Ta-29.2Nb-4.3Zr)-10HA-0.1La-xGNFs (wt %, x = 0.5, 1.0, 1.5). As shown in Figure 1 , the surface modification of graphene was performed by using a rutin solution at the beginning of the experiment [ 30 ]. Next, the raw powders were treated by mechanical alloying at a constant speed (380 rpm) for 5 h, and the obtained powders were sintered by a vacuum hot-pressing furnace (VHP-V).…”

Tribological Behavior of AA1050H24-Graphene Nanocomposite Obtained by Friction Stir Processing

“…Graphene, the perfect two-dimensional lattice of carbon atoms, has been the focus of attention in recent years, mainly due to its excellent mechanical and physical properties, such as high Young's modulus (1 TPa), high fracture strength (125 GPa), and extreme electrical and thermal conductivity [1][2][3][4][5]. Graphene has also excellent friction and wear resistance, which has turned it into a very attractive material for several applications in nanotechnology [6][7][8][9][10]. Specifically, Lee et al [10] studied the tendency towards friction decrease with the increase in the number of layers of multilayer graphene.…”