A novel method for the manufacture of porous structures with multi-component, coated pores

A novel process is demonstrated which is able to produce porous structures with internal coatings. This is achieved using sacrificial porogens which are coated with a powder and which are then infiltrated by compression moulding using a molten polymer. The coating powder is transferred to the pore and multi-material or compositionally-gradient coatings are produced. The interconnectivity of the porous structure is reduced when the pores are coated, but can be increased by reducing the degree of powder coverage of the porogen

Porous poly-ether ether ketone (PEEK) manufactured by a novel powder route using near-spherical salt bead porogens: characterisation and mechanical properties

Porous PEEK structures with approximately 85% open porosity have been made using PEEK-OPTIMA® powder and a particulate leaching technique using porous, near-spherical, sodium chloride beads. A novel manufacturing approach is presented and compared with a traditional dry mixing method. Irrespective of the method used, the use of near-spherical beads with a fairly narrow size range results in uniform pore structures. However the integration, by tapping, of fine PEEK into a pre-existing network salt beads, followed by compaction and “sintering”, produces porous structures with excellent repeatability and homogeneity of density; more uniform pore and strut sizes; an improved and predictable level of connectivity via the formation of “windows” between the cells; faster salt removal rates and lower levels of residual salt. Although tapped samples show a compressive yield stress N1 MPa and stiffness N30 MPa for samples with 84% porosity, the presence of windows in the cell walls means that tapped structures show lower strengths and lower stiffnesses than equivalent structures made by mixing

Studi Eksperimental Nanorefrigeran Tio2-r600a Sebagai Refrigeran Masa Depan

The use of CFC refrigerants (Chloro Fluoro Carbon) leads to destruction of ozone layer and global warming. An alternative refrigerant is hydrocarbon refrigerant, but it has the disadvantage of easily exploded. This experimental study has been conducted to study the effect of addition of TiO2, which are flame retardant, on the performance of hydrocarbon refrigerant R600a (nanorefrigeran TiO2-R600a). Test of Performance conducted according to refrigerants national standards IEC 60335-2-24-2010. The result is R600a-TiO2 is safe and efficient to be used as a refrigerant without any modification on refrigerator. TiO2 increases the thermal conductivity and heat transfer of refrigerant. The best performance is obtained at TiO2 concentration of 1 g / L (COP = 4,821). It is expected that the nanorefrigeran TiO2-R600a can be used as the primary refrigerant in the future that are environmentally friendly and efficient

Porous titanium manufactured by a novel powder tapping method using spherical salt bead space holders: characterisation and mechanical properties

Porous Ti with open porosity in the range of 70–80% has been made using Ti powder and a particulate leaching technique using porous, spherical, NaCl beads. By incorporating the Ti powder into a pre-existing network of salt beads, by tapping followed by compaction, salt dissolution and “sintering”, porous structures with uniform density, pore and strut sizes and a predictable level of connectivity have been produced, showing a significant improvement on the structures made by conventional powder mixing processes. Parts made using beads with sizes in the range of 0.5-1.0 mm show excellent promise as porous metals for medical devices, showing structures and porosities similar to those of commercial porous metals used in this sector, with inter-pore connections that are similar to trabecular bone. The elastic modulus (0.86GPa) is lower than those for commercial porous metals and more closely matches that of trabecular bone and good compressive yield strength is retained (21MPa). The ability to further tailor the structure, in terms of the density and the size of the pores and interconnections has also been demonstrated by immersion of the porous components in acid