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In this paper, Cr3C2/epoxy composite material was prepared by infiltration of the epoxy to porous Cr3C2 ceramic. The microstructures, hardness and wear resistance of the composite materials were investigated with the porous Cr3C2 as a compared material by scanning electron microscope, hardness tester and pin-on-disc tribometer. Most pores in the po...
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... it will have enough time to grow to big size. However, for the Cr 2 O 3 beyond the surface, the liberated [C], which is from the decomposition of CH 4 , has to transfer to the reaction interface through surface of the carburization reaction. This will decrease the carburization chance of Cr 2 O 3 and reduce the growth time of Cr 3 C 2 grain. Fig. 5 displays Cr 3 C 2 -epoxy interface with higher magnificent image of Cr 3 C 2 /epoxy composite materials. Between Cr 3 C 2 and epoxy, an obvious interface like a foam film less than 1 μm exhibits. Although it differs to the interface formed as a consequence of natural phenomena in multiphase materials, the interface could enhance the ...
Citations
... WCCrNi materials are more commonly used in coating applications, and (W, Cr) 2 C, Cr 3 C 2 are the two common secondary hard phases enabling excellent wear resistance, oxidation and corrosion properties even at elevated temperature of 760°C (Bolelli et al. 2014;Cho et al. 2009). Cr 3 C 2 was reported in the literature (Kang et al. 2016) to have excellent properties in terms of compression strength (4.1 GPa), hardness (10-18 GPa (1020-1835HV)), Young's modulus (373 MPa) and medium fracture toughness (5.5 MPa·m 1/2 ). WC-(W, Cr) 2 C-Ni was proved to have better dry sliding wear resistance than the WCCoCr samples at a temperature above 600°C (Bolelli et al. 2014). ...
Additive manufacturing techniques provide alternative methods to the conventional powder metallurgy for the fabrication of difficult-to-be-machined hard metals. Binder Jetting is particularly suitable for the fabrication of crack-free hard metals as compared to other energy-based additive manufacturing techniques since there is no direct high energy heat input during the 3D printing process. To explore the fabrication process of hard metals and their potential applications, high-density crack-free WC–45Cr–18Ni parts were fabricated using Binder Jetting and sintering in this study. The sintering temperature of 1350°C was found to contribute to the best combination of properties with 98.63% density, >1200 HV 0.3 hardness, compression strength >2200 MPa and compressive elastic modulus of 142 GPa. These parts also possess good oxidation resistance, corrosion resistance and dimensional stability. The Binder Jetting fabricated WC–45Cr–18Ni part shows the potential to be applied as mould material working at high temperatures and where corrosion, oxidation and wear resistance are required.
... Chromium carbide (Cr 3 C 2 ), as a typical representative, demonstrates excellent properties, including high melting point (1810 • C), excellent compressive strength (4.1 GPa [2]), high hardness (Hv, 18 GPa [3]), low density (6.68 g/cm 3 [4]) and good resistance to oxidation, corrosion, and wear. As a result, Cr 3 C 2 has been widely used in a variety of industrial applications, such as rocket nozzles, shaft seals, shaft bearings, cutting tools, and anticorrosive coating [5][6][7]. ...
... As mentioned above, a Cr 3 C 2 phase with good crystallinity could be synthesized at 1000 • C for 1 h. The synthesis temperature required by the method here described was at least 400 • C lower than that of the conventional method (1400 • C) [5]. Furthermore, the synthesis temperature was 100 • C lower than those of the precursor and carbon thermal reduction methods [24,25]. ...
... As mentioned above, a Cr3C2 phase with good crystallinity could be synthesized at 1000 °C for 1 h. The synthesis temperature required by the method here described was at least 400 °C lower than that of the conventional method (1400 °C) [5]. Furthermore, the synthesis temperature was 100 °C lower than those of the precursor and carbon thermal reduction methods [24,25]. ...
Chromium carbide nanopowders were synthesized by mechanical alloying-assisted microwave heating. The effect of gamma irradiation on phase composition and microstructure of chromium carbide nanopowders synthesized by the microwave heating method was analyzed. The samples were characterized by X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM) techniques. The results showed that well-dispersed chromium carbide nanopowders can be synthesized by maintaining the temperature at 1000 °C for 1 h. Gamma ray irradiation had an important effect on the microstructure of chromium carbide nanopowders. The interplanar spacings of chromium carbide (110) crystal faces before and after gamma ray irradiation were 0.3725 nm and 0.3824 nm, respectively. The crystal structure of chromium carbide was changed by gamma ray irradiation. Gamma ray irradiation can also increase the binding energy of chromium carbide, which is beneficial to improve the thermal stability and mechanical properties of chromium carbide at high temperature.
In this study, a superhydrophobic Cr porous surface with better abrasive resistance was prepared on Ti6Al4V substrates by double glow plasma surface alloying and the plasma reverse sputtering process. These results showed that the Cr coating with rough and porous micro-nano structures was formed on the surface of Ti6Al4V alloy, which could be attributed to the Kirkendall effect during the process of the plasma reverse sputtering. The role of the reverse sputtering time on the structure and performance of the Cr porous coatings was investigated systematically. The thickness of Cr diffusion layers increased from 13 μm to 28 μm as the reverse sputtering time increased to 45 min. The friction behavior was revealed by wear test, demonstrating prominent improvement of wear resistance. Meanwhile, the as-prepared micro-nano structured Cr coatings exhibited superhydrophobic properties with ultrahigh adhesion.
The present chapter provides comprehensive literature survey undertaken on the use of nanocomposites for both structural and energy applications. Research in the development of polymer-based composites for structural and energy applications is gaining prominence in the present scenario due to their unique lightweight and high-strength properties. Plain polymer alone cannot provide the deserved strength required for the structural applications due to the brittle nature of the plastics. Such drawbacks of polymeric materials can be suitably addressed by reinforcing it with strength fillers at both micro- and nano-level. However, continuous effort has been made by several investigators to improve the mechanical properties of polymers by adopting several reinforcement techniques. Recently usage of nano-materials in polymer-based matrix for varied applications is gaining tremendous importance due to their unique physical and chemical properties as compared to conventional strength fillers like carbon fibers, natural fibers unlike. Carbon nanostructures, such as graphene and fullerenes, have gained prominence for energy storage, and this is mainly attributed to their large aspect ratios, specific surface areas, and electrical conductivity (as reported by Sharma and Bhatti 51:2901-2912, 2010; Boota et al. 161:A1078-A1083, 2014). This chapter highlights on the advances made in energy storage applications involving multifunctional carbon nanostructures.
Metal-polymer composites can be used to synthesize material properties. A variety of interpenetrating phase composites have been produced by spontaneously infiltrating porous short-fiber preforms with unsaturated polyester resin under vacuum conditions. Porous preforms are fabricated by compacting and sintering short 304 stainless steel fibers from cutting stainless steel fiber ropes. Tensile experiments are conducted, and fractographs are examined via scanning electron microscopy. The results reveal that the tensile strength, elongation at maximum stress, and elasticity modulus of the IPCs increase with the increasing fiber fractions and exhibit anisotropy in different directions. The tensile strength and elongation at maximum stress are significantly improved compared with the consistent preforms. A nonlinear elastic behavior and sawtooth-like fluctuation during yield deformation are noted. Compared with the through-thickness direction, a higher tensile strength and larger elongation at maximum stress are observed in the in-plane direction. Finer-diameter fibers can improve the strength and increase the elongation at maximum stress. The tensile fracture surfaces show a mixture of brittle and plastic fracture characteristics.
