Untitled

Microstructure examination of functionally graded NiTi/NiAl/Ni3Al intermetallic compound produced by self-propagating high-temperature synthesis

“…As the production methods of FGM: magnetic spraying, physical vapor decomposition, dynamic ion mixing, chemical vapor infiltration, and reaction bonding methods along with powder metallurgy (P/M) techniques, plasma spraying techniques, chemical vapor decomposition, self-propagating high-temperature synthesis (SHS), were used. Powder metallurgy techniques used among these methods are mostly used for the production of FGMs consisting of plates (layers) having millimeter thick dimensions due to self-propagation speed, and simplicity and economy of the method [9][10][11]. SHS method, which is one of the most preferred methods among the powder metallurgy methods, becomes prominent as an advanta-T a b l e 1.…”

In Situ Reinforcement of Ti6Al4V Matrix Composites by Polymer‐Derived‐Ceramics Phases

“…Commonly, by tailoring the polymer composition and architecture it is possible to obtain, after crosslinking and pyrolysis (800-1200°C in nitrogen or argon atmosphere), various ceramic phases (SiC, SiOC, Si 3 N 4 , SiCN, Si(E)OC, and SiECN, where E ¼ Al, B, Ti, …) with different structures at the nano-and micrometer-range. In ref., [10] the use of PPs was tested for the production of functionally graded materials using Cu and Al powders as metallic matrix and polycarbosilane as PP. Traditionally, PPs and metals are mixed together to prepare ceramics via active filler-controlled pyrolysis (AFCOP).…”

“…A novel technique to produce in situ reinforced metal matrix composites (MMCs) by dispersing silicon based preceramic polymers (PP) in metals was reported by Yiajima et al [9] and by Czubarow and Seyferth. [10] Recently, Castellan et al [11] and Sudarshan et al [12] have proposed this technique to produce in situ Cu-based and Mg-based MMCs, via a PM and a casting process, respectively, achieving the subsequent polymer-to-ceramic conversion by a controlled thermal treatment at elevated temperature. Recently, Handtrack et al [13] reported the use of a liquid molecular precursor (hexamethyldisilane, HMDS) for ceramic particles within a Ti matrix sintered via spark plasma sintering (SPS).…”

“…[17,18] In Yiajima et al's [9] investigations, concerning the mixing of Fe-Cr powders and PCS (polycarbosilane), the oxidation resistance of the composite was studied in comparison to the standard Fe-Cr alloy, and the weight change after heating in air at 1000°C was almost zero for the composite containing 10 wt% of polymer. In ref., [10] the use of PPs was tested for the production of functionally graded materials using Cu and Al powders as metallic matrix and polycarbosilane as PP. In ref., [11] the Cu-based matrix composites reinforced with a PSZ (polysilazane) showed high microhardness values that remain unaltered up to 0.9 the melting temperature.…”

Self-Organization of the Compositional Gradient Structure in Hyaluronic Acid and Poly(N-isopropylacrylamide) Blend Film

“…In nature, gradient biological structures exist most commonly, such as the structure of bamboo [6], shells, teeth, bones, tendon and extracellular matrix (ECM) [7]. Man-made functionally gradient materials (FGMs) have been developed for combining irreconcilable properties within a single material and have been widely incorporated in metal/ceramic and organic/inorganic material fields for increasing the structural complexity and combining different functionality [8][9][10].…”