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The paper considers the process of creation of an aluminum bronze-based metal-matrix composite straightened with tungsten carbide particles by the method of electron-beam additive manufacturing. To create composites, a combined printing method with powder and wire material feeding has been used. The microstructure study showed that varying the printing parameters during the process has made possible to achieve a homogeneous distribution of particles of the strengthening phase in the matrix. Carbide particles undergo refining caused by the electron beam. The particles size of obtained composite is 4 times finer compared to the initial powder size. Dry sliding wear studies showed strong wear character and dependence of the friction coefficient on the hardening particles size. [ABSTRACT FROM AUTHOR]

Many process parameters of air plasma spray, such as deposition power, speed, and working distance, significantly influence the resulting microstructural, mechanical, tribological, and corrosion properties of the deposited coatings. Among these parameters, the feed rate plays a vital role in the microstructural evolution and achieved properties. Thus, this study investigates the effect of feed rates (10, 20, and 45 g/min) on the microstructure, tribological, and corrosion of Fe–Cr–Mo–B–C composite coatings fabricated using air plasma spray. The results showed that as the powder feed rate was reduced, the thickness, porosity, and amorphous fraction of the coating decreased due to a higher temperature and velocity of the particles at the point of impact. The lower feed rate increased the formed crystalline phases (Fe, Cr, Mo)23C6 and (Fe, Cr, Mo)7C6, which were embedded in the amorphous matrix. As a result, the hardness increased from about 0.72 GPa (at 45 g/min feed rate) to about 1.0 GPa (at 20 g/min feed rate) and 1.3 GPa (at 10 g/min feed rate). Similarly, the elastic modulus increased from about 40 GPa at 45 g/min feed rate to about 52 and 68 GPa at 20 and 10 g/min feed rates, respectively. Consequently, the sliding wear resistance was improved by up to 27 and 50% at a reduced feeding rate of 20 and 10 g/min, respectively. The principal wear mechanisms were adhesion and oxidation. The electrochemical corrosion resistance in a 3.5% NaCl solution was significantly increased at the lowest feed rate. [ABSTRACT FROM AUTHOR]

Since the last few decades, plasma spraying has gained its reputation to produce excellent metallic glass coatings because of its high process controllability. Present work studies the effect of various plasma spray parameters on the mechanical, tribological and the corrosion properties of plasma sprayed Fe-based bulk metallic glass (BMG) coating. The in-flight particle velocity and temperature were monitored using the accuraspray diagnostic sensor. Among different sets of parameters, combination of higher power at lower feed rate and higher gas flow provided the maximum density of the coating due to better melting of the particles. XRD analysis showed that high-temperature exposure of the in-flight particles incepted few traces of oxides and carbides in the coating, apart from the intrinsic α- and γ-phases of the Fe-based feedstock. The corrosion resistance of the coatings was highly influenced by the stand-off distance, keeping all the other parameters at higher values. The reason may be attributed to the more number of powder particles melting at higher power and impinging on the substrates at quite lesser time. Current work concludes that the various properties of the Fe-based BMG coating are seriously tailored by different sets of plasma parameters that urge to govern the overall coating properties. [ABSTRACT FROM AUTHOR]

The influence of rolling temperature on the microstructure and mechanical properties of AA5083-1% Al2O3 composites has been analyzed in this study. The alloy was deformed with the method of warm accumulative roll bonding in various temperature conditions, i.e., at ambient temperature, 200°C, and 300°C up to 5 cycles (휀 = 4). The structure has been studied with scanning electron microscopy (SEM), and mechanical properties of the deformed material have been measured by tensile test as well as Vickers microhardness test. It was established that the rolling temperature had a significant effect on the mechanical properties and microstructure of the manufactured MMCs. High strength, low elongation, and high average Vickers microhardness were obtained for the material processed at lower temperatures, i.e., at ambient temperature. Whereas, by increasing the rolling temperature to 300°C, the toughness and elongation ranges were greater than for the MMCs manufactured at lower temperatures. [ABSTRACT FROM AUTHOR]

Four kinds of C f /Mg composites with different fabric architectures were fabricated by liquid–solid extrusion following vacuum infiltration (LSEVI) technique. The influence of fabric architecture on compressive properties of C f /Mg composites was investigated, and the microstructure and failure surfaces were examined by SEM. The results showed that C f /Mg composites were anisotropic material and the fabric architecture had great influence on their compressive performance. Moreover, fabric crimp had a negative influence on compressive properties of C f /Mg composite. The composite with non-woven carbon fabric perform had the highest compressive strength ( XY direction). Compared with 3 K plain-woven carbon cloth composite whose fiber bundles had 3000 monofilaments, 1 K plain-woven carbon cloth composite had better compressive properties. The analysis of failure surface indicated that the failure modes of C f /Mg composites were mainly shear failure and delamination failure. [ABSTRACT FROM AUTHOR]

Many traditional methods for strengthening martensitic stainless steel (SS) typically come at the sacrifice of ductility. Herein, we report a configuration design of ceramic particles for reinforcing additively manufactured 15-5 PH martensitic SS with an optimized combination of high-strength and impressively larger ductility via the micron-sized TiC addition. High strength is ascribed to grain refinement, Orowan bowing strengthening, and abundant nucleation of nanoscale (Nb,Ti)C precipitates, while high elongation correlates to the reduced oxide inclusion content, martensite/austenite duplex microstructure, and progressive transformation-induced plasticity effect. In addition, severe localized corrosion is completely inhibited. This work shows the great potential of additive manufacturing technology to fabricate Fe-based composites with unique microstructures, low residual stress levels, excellent corrosion resistance, and an exceptional combination of strength and ductility for practical applications. [ABSTRACT FROM AUTHOR]