Fabrication and characterisation of microporous titanium

Microporous titanium was fabricated by a special powder metallurgy process and the microstructure and the mechanical properties of the material were characterised by scanning electron microscopy and quasi-static compression. The pore sizes and porosities of the samples are ranged of 10-50 μm and 40-65%, respectively. Macroporous Ti samples with the pore sizes ranged from 500 to 800 μm were also prepared by the similar process for comparison. The microporous Ti exhibits not only a very different deformation behaviour from the macroporous Ti but also lower flow stress than the latter, completely different from those observed in common porous metals.

Fabrication of carbon nanofiber by pyrolysis of freeze-dried cellulose nanofiber

The possibility of fabricating carbon nanofibers from cellulose nanofibers was investigated. Cellulose nanofiber of ~50 nm in diameter was produced using ball milling in an eco-friendly manner. The effect of the drying techniques of cellulose nanofibers on the morphology of carbon residue was studied. After pyrolysis of freeze-dried cellulose nanofibers below 600 °C, amorphous carbon fibers of ~20 nm in diameter were obtained. The pyrolysis of oven-dried precursors resulted in the loss of original fibrous structures. The different results arising from the two drying techniques are attributed to the difference in the spatial distance between cellulose nanofiber precursors.

Focused ion-beam (FIB) fabrication of micro-sized pillars for microcompression test

Pillars were fabricated by focused-ion beam (FIB) in a dual beam scanning electron microscope (SEM, FEI Quanta 3D). A multi-step milling procedure was adopted to prepare the pillars using Ga+ ion beam operated at 30 kV. The beam current was reduced from 5 nA for coarse milling down to 50 pA for fine milling, to minimize the surface damage induced by the Ga+ ion beam. The pillars were imaged at 52° tilt angle by SEM prior to the microcompression tests.

An illustration of the physical robustness of silica monolithic rod columns

A commercial silica monolithic rod column (100 × 4.6 mm) was cut into smaller sections using a saw. Each time a section was cut from the column, the performance of the remaining intact monolith was retested. No significant change in the performance of the bed was recorded following the removal of 40 mm of the column in three separate cut sections. The work illustrates that monoliths are extremely robust and that they can be remodelled to different lengths if required, or a blocked section of the column (i.e. inlet) could be removed in much the same manner as for GC columns.

Fabrication of Ti14Nb4Sn alloys for bone tissue engineering applications

In this paper, porous Ti14Nb4Sn alloys were fabricated using a space holder sintering method, resulting in a porosity of ~70%. Scanning electron microscopy (SEM) analyses revealed a combination of both macropore and micropore structures. The fabricated titanium alloy scaffolds exhibited a similar structure to that of natural bone, which is expected to improve bone implant longevity. Bacterial cells of Pseudomonas aeruginosa ATCC 9027 were employed for the in vitro test.

Fabrication, microstructure and mechanical properties of high performance ferrite-bainite steels

Low cost ferrite and bainite(FB) steels offer the prospect of high ultimate tensile strength combined with high hole expansion ratio. The enhanced strain hardening and formabilityof FB steels were primarily associated with the fine ferrite matrix, the low residual stresses and dislocation densityand compatible deformation between both phases.This overview describes the various techniques to produce FB steels, and comparestheresulting microstructure, tensile propertiesand tretchflangeabilitywith conventional HSLA and DP steels.A new generation of ultrafine ferrite and nano-scalebainiteautomotive steelsisunder development forthe futuredemands of extremely high strength and ductilitythroughthe fabricationtechnologiesinvolvingphase transformationsandplastic deformation.

V2O5·nH2O crystalline nanosheets : hydrothermal fabrication and structure evolution

V2O5·nH2O nanosheets are fabricated hydrothermally with the acidified peroxovanadate solution at 200 °C for 12 h. The X-ray diffraction suggests that V2O5·nH2O nanosheets display lamellar ordering along c-axis direction. Transmission electron microscopy, field-emission scanning electron microscopy, and selected area electron diffraction indicate that V2O5·nH2O nanosheets are very thin in thickness and micron-sized in lateral dimension, and they are two-dimensional crystallites. X-ray photoelectron spectroscopy and thermogravimetric analysis are utilized to confirm the elemental composition of nanosheets. The formation process of nanosheets is also discussed in terms of time- and temperature-controlled experiments.

Fabrication and characterisation of carbon nanofibres from cellulose nanofibres

Carbon nanofibers were fabricated by pyrolysis of plant-based cellulose nanofibers. The findings demonstrate the possibility of obtaining strong and commercially competitive carbon nanofibers that are used in many industries including aerospace, automobile and electronics.