Directionally freeze-cast titanium foam with aligned, elongated pores

Microstructural Characterization of Hard Ceramics

“…(Chen et al, 2010, Chino andDunand, 2008) Contrast in the radiographs arises from differences in absorption coefficients, so it is generally applied to multiphased materials and composites. Compared to electron tomography, the imaging conditions are much more straightforward and there is no limit on the angular range.…”

“…(Barnard et al, 2006, Batenburg et al, 2009, Mobus and Inkson, 2001, Weyland et al, 2006 The Dual Beam, Focused Ion Beam Scanning Electron Microscope (DB--FIB SEM) makes three--dimensional imaging and crystallography mapping possible at the submicron level. (Dillon and Rohrer, 2009b At larger length scales, X--ray tomography (Chen et al, 2010, Chino andDunand, 2008) and high energy X--ray diffraction microscopy (HEDM) (Hefferan et al, 2009, Larson et al, 2002, Poulsen et al, 2001) allow phase mapping and crystallographic mapping, respectively. Finally, at the largest length scale, "RoboMet" robotic polishing and metallography allows the three--dimensional imaging of samples with sizes up to the cm size range.…”

Open pore titanium foams via metal injection molding of metal powder with a space holder

“…Almost all production processes for titanium foams use metal powder. These include the impregnation of polymer foams [7], Gel casting [8], freeze casting [9], slip casting [10] as well the space holder technique [11][12][13] with all of these the challenge is to control the process to achieve the desired structure, retaining porosity, while obtaining good integration of the powder for good mechanical properties . The first four techniques are relatively slow processes and need a long processing times resulting in low output in comparison with other foaming techniques, such as the space holder technique (i.e.…”

Pore structures and mechanical properties of porous titanium scaffolds by bidirectional freeze casting

“…The mechanical properties of the materials can be controlled by the porosity, pore size and pore morphology through a variety of manufacturing methods [6]. So far, many manufacturing techniques have been reported to produce porous titanium such as bubble generation [7,8], replication of polymeric sponge [9,10], rapid prototyping method [11,12], space holder method [13,14] and freeze casting [15,16].Freeze casting is a promising method to prepare porous materials with unique aligned and elongated pore structure by driving particles of the slurry to self-assemble along the ice growth direction [6,17]. The pore morphologies are mainly determined by matrix powder kinds, solvent types and frozen temperature gradient [18].…”

“…The mechanical properties of the materials can be controlled by the porosity, pore size and pore morphology through a variety of manufacturing methods [6]. So far, many manufacturing techniques have been reported to produce porous titanium such as bubble generation [7,8], replication of polymeric sponge [9,10], rapid prototyping method [11,12], space holder method [13,14] and freeze casting [15,16].…”