Abstract. The fabrication of a composite material based on magnesium (Mg) and tricalcium phosphate is reported in this work. Rods of β-tricalcium phosphate (β-TCP) were processed and consolidated together with pure Mg powder through spark plasma sintering (SPS). The microstructure at the interface, the chemical composition and transformation of the components and the microhardness were analysed. The microstructure of the composite shows two zones with welldefined and continuous interface between them: a ceramic zone composed by β-TCP filled with Mg and the metallic zone constituted by Mg and Mg rich eutectic. Vickers hardness shows the excellent mechanical interaction between the two zones.

No abstract

As a potential candidate for the top coating in novel Environmental Barrier Coating systems, one representative of a Barium-Magnesium-Aluminium-Silicate family was produced in the form of the powder. Initial compounds were heat-treated to synthesize and the product was crushed in the ball mill device down to the fraction of 20 micrometers. In the next step, the atmospheric plasma spray (APS) technique was used to form a coating on a steel sheet substrate. The aim of this study was to obtain the most favorable technological parameters for the thermal spraying process and therefore two plasma spraying parameters for pure alumina or yttria stabilized zirconia, and other three experimentally designed ones were tested. Despite the same stand-off distance used for coatings manufacturing, thickness and porosity differed in order of tens of micrometers and several percent, respectively. Resulting coatings consisted of a mixture of amorphous and crystalline Al2O3, SiO2 and MgO phases.

Abstract. The usage of iron alloys for bone fractures treatment has been limited due to its high density and elastic modulus, as compared to bone. In contrast, the use of tricalcium phosphate (TCP), a ceramic that promotes bone healing, is mostly limited by its brittle nature. In the present work the fracture mechanism of a novel iron-TCP interpenetrated composite fabricated by spark plasma sintering was studied. Specimens were subjected to a diametral tensile-strength-test. The work of fracture was determined by indirect tensile loading conditions using the diametral tensile strength test. The results revealed that iron has a clear toughening effect on the microstructure of tricalcium phosphate specimens consolidated by spark plasma sintering. This is a promising result to overcome the limited usage of tricalcium phosphate to treat only non-load bearing bone defects.

A general overview on the processing of a series of advanced engineering materials, synthesized via pulsed-electric-current-sintering related techniques, and the similarities in between those techniques are introduced in this work. This paper is focused on two major techniques; namely, the Spark Plasma Extrusion (SPE) and Current Assisted Infiltration Sintering (CAIS), which in turn are derived from the Spark Plasma Sintering (SPS) technique, all widely used by this research group. Not only the geometry but also the microstructure of thus prepared specimens might vary depending on the selected technique. The resulting specimens can be under the forms of discs (flat or thick coin-like), rivets (enlarged cylindrical bars)-like and/or disclosing interpenetrated periodic networks with regular or irregular (either coin or rivet/screw)-like specimens, respectively. As for the CAIS technique, either 3D printed ceramic frameworks or naturally synthesized porous substrates (such as bone-like structures), can be infiltrated with virtually any metal or alloy. Among the series of produced materials we can include, for example: biomaterials such as: Ti-and Mg-hydroxyapatite, pure hydroxyapatite HA, composites, e.g., Al5083-CNT ́s, just to name a few. The expanding possibilities of SPS, SPE and CAIS techniques are briefly indicated here.