Layer-wise slurry deposition (LSD) is an approach in solid freeform fabrication (SFF), that can be used for fabrication of hydroxyapatite (HA) bone implants. In view of biocompatibility, HA is a suitable ceramic material for hard tissue replacement implants. SFF technique is the prototyping of objects directly from computer models without part-specific tooling or human intervention. A slurry is...

We simulate the sintering of particle aggregates due to surface diffusion. As a method we use Kinetic Monte-Carlo simulations in which elasticity can explicitly be taken into account. Therefore it is possible to investigate the shape relaxation of aggregates also under the influence of an external pressure. Without elasticity we investigate the relaxation time and surface evolution of sintering...

The aim of the present investigation is to study the sintering behavior of the Cu12Sn bronze system in both, a microwave furnace as well as a conventional furnace. The powders prepared by premixed and prealloyed routes were sintered in the range of solid state, transient and supersolidus liquid phase sintering conditions. The comparative analysis is based on the sintered density, densification ...

Conventional and new sintering mechanisms have been porous compacts is well-known in the ceramic literature. However, several reports have been presented recently that investigated using fine powders of CeO2 and Y2O3 of excellent sinterability. We have verified the validity of Herring’s show that particle/grain size can remain essentially constant up to a density of 92%, and such a resistance t...

This paper treats modeling and control for the burnthrough point in industrial sintering processes. First, a simple state-space model for event-time dynamics is derived for a complicated system by introducing events into a continuous variable system. For the control of the sintering process, a twostage control policy is used. First, optimal interevent time is obtained from an output-constrained...

The sintering and the crystallization of two iron-rich glass compositions (45–75m powder fractions) were studied in air and nitrogen atmospheres. The phase formation was evaluated by differential thermal analysis, while the densification, by dilatometry; the crystalline phases were identified by X-ray diffraction and the structure observed by scanning electron microscopy. It was highlighted tha...

Y2O3:Eu were prepared through precursors synthesized by leaching tests, removing impurities, enrichment of Y and Eu from residual purified liquors, annealing treatment, and high temperature solid-state reaction method, which is the most suitable for large-scale production. The analysis of product shows that the purity is 99.42%. The resultant powders were characterized by X-ray diffraction (XRD...

Zirconia-toughened alumina (ZTA) using yttria-stabilised zirconia is a good option for ceramic-ceramic bearing couples for hip joint replacement. Gelcasting is a colloidal processing technique capable of producing complex products with a range of dimensions and materials by a relatively low-cost production process. Using gelcasting, ZTA samples were prepared, optimising the stages of fabricatio...

This paper summarizes the state of the art of direct metal laser-sintering (DMLS) in 2004, put into perspective by a review of its history from its roots in the 1970s, and discusses the trends going into the future. Since the 1970s, DMLS has evolved from an idea to a powerful commercial technology. The "family tree" of DMLS is explained with reference to related methods such as laser-cladding, ...

The thermoelectric properties of Bi2Te3 nanowire/graphene composites prepared at different sintering temperatures have been investigated. The as-synthesized ultrathin Bi2Te3 nanowires are uniformly distributed between the graphene layers, leading to the formation of Bi2Te3 nanowire/graphene layer-by-layer hybrid structures. The electrical conductivity of the as-sintered composites increases dra...