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Self-propagating High-temperature Synthesis (self-propagating + high-temperature_synthesis)
Selected AbstractsEnhanced Ductility of Dendrite-Ultrafine Eutectic Composite Fe3B Alloy Prepared by a Self-Propagating High-Temperature Synthesis,ADVANCED ENGINEERING MATERIALS, Issue 3 2009Licai Fu The bulk dendrite-ultrafine eutectic composite Fe3B alloy was prepared by a self-propagating high-temperature synthesis. This technique is convenient, low cost, and capable of being scaled up for processing bulk nano/ultrafine-structured materials. The Fe3B alloy is composed of a micrometer-sized dendrite dispersed in an ultrafine laminar eutectic matrix and exhibits both high strength and large ductility in compressive tests. [source] Porous TiNi Biomaterial by Self-Propagating High-Temperature Synthesis,ADVANCED ENGINEERING MATERIALS, Issue 6 2004J.S. Kim Abstract Porous TiNi shape-memory alloy (TiNi SMA) bodies with controlled pore structure were produced from the (Ti+Ni) powder mixture by self-propagating high-temperature synthesis (SHS) method. The effect of processing variables such as the kind of starting powders, ignition temperature and preheating schedule on the behavior of combustion wave propagation, the formation of phases and pore structure was investigated. The relationship between pore structure and mechanical properties was also investigated. An in vivo test was performed to evaluate bone tissue response and histocompatibility of porous TiNi SMA using 15 New Zealand white rabbits. No apparent adverse reactions such as inflammation and foreign body reaction were noted on or around all implanted porous TiNi SMA blocks. Bone ingrowth was found in the pore space of all implanted blocks. [source] Self-Propagating High-Temperature Synthesis of Ti3SiC2: II.JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 10 2008Kinetics of Ultra-High-Speed Reactions from In Situ Neutron Diffraction In situ neutron diffraction data at 0.9-s time resolution during the self-propagating high-temperature synthesis of Ti3SiC2 from stoichiometric 3Ti+SiC+C mixtures have been further analyzed to give the phase quantities during all five stages of the identified reaction [(i) preheating, (ii) ,,, phase transformation in Ti, (iii) preignition reactions, (iv) intermediate phase formation, and (v) rapid nucleation and growth of Ti3SiC2]. The phase quantities thus determined have been used, in conjunction with temperatures estimated from lattice parameters and thermal expansion data, to determine the kinetic parameters for the nucleation and growth stage using a nonisothermal form of the Avrami kinetic equation. The analysis gave an Avrami exponent, n, close to 3 in agreement with nucleation and the observed two-dimensional growth of Ti3SiC2 crystals. An activation energy of ,45 kJ/mol was also estimated. [source] Zirconia-Based Metastable Solid Solutions through Self-Propagating High-Temperature Synthesis: Synthesis, Characterization, and Mechanistic InvestigationsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 8 2000Filippo Maglia Cubic Zr1,xMexOy(Me = Fe, Co, Ni, Cu) metastable solid solutions with metal content significantly higher than equilibrium levels have been synthesized by the self-propagating high-temperature synthesis method based on a thermite reaction between metallic zirconium and the transition-metal oxides CoO, Fe2O3, CuO, and NiO. Through in situ XRD analysis, it was determined that when heated to 1100°C, the cubic solid solution transformed to the tetragonal phase with the concomitant formation of iron oxide. When cooled to lower temperatures, the tetragonal phase transformed to the monoclinic phase at or below 500°C. Results of auxiliary experiments strongly suggest that the formation of the solid solution takes place behind the combustion front by a reaction between zirconia and the metal. [source] Enhanced Ductility of Dendrite-Ultrafine Eutectic Composite Fe3B Alloy Prepared by a Self-Propagating High-Temperature Synthesis,ADVANCED ENGINEERING MATERIALS, Issue 3 2009Licai Fu The bulk dendrite-ultrafine eutectic composite Fe3B alloy was prepared by a self-propagating high-temperature synthesis. This technique is convenient, low cost, and capable of being scaled up for processing bulk nano/ultrafine-structured materials. The Fe3B alloy is composed of a micrometer-sized dendrite dispersed in an ultrafine laminar eutectic matrix and exhibits both high strength and large ductility in compressive tests. [source] Porous TiNi Biomaterial by Self-Propagating High-Temperature Synthesis,ADVANCED ENGINEERING MATERIALS, Issue 6 2004J.S. Kim Abstract Porous TiNi shape-memory alloy (TiNi SMA) bodies with controlled pore structure were produced from the (Ti+Ni) powder mixture by self-propagating high-temperature synthesis (SHS) method. The effect of processing variables such as the kind of starting powders, ignition temperature and preheating schedule on the behavior of combustion wave propagation, the formation of phases and pore structure was investigated. The relationship between pore structure and mechanical properties was also investigated. An in vivo test was performed to evaluate bone tissue response and histocompatibility of porous TiNi SMA using 15 New Zealand white rabbits. No apparent adverse reactions such as inflammation and foreign body reaction were noted on or around all implanted porous TiNi SMA blocks. Bone ingrowth was found in the pore space of all implanted blocks. [source] Microstructural analysis of iron aluminide formed by self-propagating high-temperature synthesis mechanism in aluminium matrix compositeJOURNAL OF MICROSCOPY, Issue 1 2006ANITA OLSZÓWKA-MYALSKA Summary An aluminium matrix composite with iron aluminide formed in situ as a result of self-propagated high-temperature synthesis was examined. The structural characteristics of the reinforcement investigated by scanning electron microscopy and transmission electron microscopy methods are presented. Iron aluminide particles with a very fine grain size and of two shapes, cubic and needle-like, were observed. No differences in their phase composition were found by the selective electron diffraction pattern method. The composite reinforcement formed in the early stage of self-propagating high-temperature synthesis consisted only of the Al3Fe phase. [source] Self-Propagating High-Temperature Synthesis of Ti3SiC2: II.JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 10 2008Kinetics of Ultra-High-Speed Reactions from In Situ Neutron Diffraction In situ neutron diffraction data at 0.9-s time resolution during the self-propagating high-temperature synthesis of Ti3SiC2 from stoichiometric 3Ti+SiC+C mixtures have been further analyzed to give the phase quantities during all five stages of the identified reaction [(i) preheating, (ii) ,,, phase transformation in Ti, (iii) preignition reactions, (iv) intermediate phase formation, and (v) rapid nucleation and growth of Ti3SiC2]. The phase quantities thus determined have been used, in conjunction with temperatures estimated from lattice parameters and thermal expansion data, to determine the kinetic parameters for the nucleation and growth stage using a nonisothermal form of the Avrami kinetic equation. The analysis gave an Avrami exponent, n, close to 3 in agreement with nucleation and the observed two-dimensional growth of Ti3SiC2 crystals. An activation energy of ,45 kJ/mol was also estimated. [source] Processing and Mechanical Behavior of CrN/ZrO2(2Y) CompositesJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 2 2000Yoshihiko Takano CrN powder consisting of granular particles of ,3 ,m has been prepared by self-propagating high-temperature synthesis under a nitrogen pressure of 12 MPa using Cr metal. Dense pure CrN ceramics and CrN/ZrO2(2Y) composites in the CrN-rich region have been fabricated by hot isostatic pressing for 2 h at 1300°C and 196 MPa. The former ceramics have a fracture toughness (KIC) of 3.3 MPa ·m1/2 and a bending strength (,b) of 400 MPa. In the latter materials almost all of the ZrO2(2Y) grains (0.36,0.41 ,m) are located in the grain boundaries of CrN (,4.6 ,m). The values of KIC (6.1 MPa · m1/2) and ,b (1070 MPa) are obtained in the composites containing 50 vol% ZrO2(2Y). [source] | ||||||||||