Si3N4/BN fibrous monoliths were prepared with 4 wt% Y2O3 added as a sintering aid to the Si3N4. Residual carbon, present in the billet before hot-pressing, was shown to influence the final microstructure. The sintering aid glass, known to migrate into the BN cell boundaries during hotpressing, was not sufficient in quantity to prevent premature shear failure when samples were tested in flexure....

An elemental powder sintering (EPS) technique has been developed for the synthesis of porous NiTi alloy, in which Ni and Ti powders are used as the reactants and TiH2 powder is added as a pore-forming agent and active agent. Effects of various experimental parameters (sintering temperature, sintering time, and TiH2 content) on the porosity, pore size and pore distribution as well as phase compo...

The U.S. Army has an interest in the use of alloys that produce excessive heat during formation and can be used for structural purposes such as shell casings. Molecular dynamics simulations have been used to provide a more thorough understanding of one of these alloys systems, namely the kinetic reaction of Ni and Al nanoparticles. We have considered the affect of primary particle size on sinte...

Biologically derived hydroxyapatite from calcinated (at 850 degrees C) bovine bones (BHA) was doped with 5 wt% and 10 wt% of SiO(2), MgO, Al(2)O(3) and ZrO(2) (stabilized with 8% Y(2)O(3)). The aim was to improve the sintering ability and the mechanical properties (compression strength and hardness) of the resultant BHA-composites. Cylindrical samples were sintered at several temperatures betwe...

A PM approach is investigated in the context of extremely fine low temperature bainitic steels with a reasonable combination of ultimate tensile strength and uniform elongation. The strategy consists of three steps. First, ball milling is used for mechanical alloying and to create a large density of interfaces prior to sintering. In the second step, spark plasma sintering is used as a rapid con...

Aluminum metal matrix composites (AMMCs) are light-weight materials having wide-spread use in the automobile and aerospace industries due to their attractive physical and mechanical properties. The promising mechanical properties of AMMCs are ascribed to the size and distribution of the reinforcement, as well as to the grain size of the matrix. Microwave rapid sintering involves internal heatin...

The applicability of irregular prealloyed Ti-6Al-4V powder for the fabrication of titanium products by pressing and sintering and its employment as a master alloy to obtain the Ti-3Al-2.5V alloy was studied. To this end, the starting powders were characterised by dilatometry, differential thermal analysis and XRD. Green samples were obtained by cold uniaxial pressing, and the evolution of the m...

Electrical heating of the graphite die and punch assembly is a unique feature of the spark plasma sintering (SPS) process. The high currents needed to heat the die, despite its low resistance, can produce an electric field across the ceramic specimens that may be enough to induce field assisted sintering. Despite the large number of publications of SPS, the electric field intensity has not been...

In this study the effect of sintering process in different temperatures on microstructure and morphological properties of sintered hydroxyapatite (HAp) was investigated. HAp powder was prepared by wet precipitation method from following reagents: Ca(OH)2 + H3PO4 in an alkaline conditions. Thermal analysis (TA), X-Ray diffraction method (XRD), FT-IR spectrometry (FT-IR) and scanning electron mic...

Aluminium based nanostructured materials with additions of 0.5, 1 and 1.5 weight% of zirconium have been produced and sintered using the spark plasma sintering technique in order to promote the nucleation of ZrAl3 platelets. The mechanical behaviour of all these nanocomposites was determined by means of the Small Punch Test. Zirconium additions significantly decrease the mechanical properties o...