Three kinds of SiC particulates (SiCp), whose diameters range from millimeter through micrometer to nanometer (designated as m-SiCp, m-SiCp and n-SiCp, respectively), were separately incorporated into an Al–6wt.%Ti–6wt.%Nb alloy by high energy ball milling. The as-milled composite particles are appreciably refined particularly when finer SiC particulate was added, and so do the in situ formed Al3Ti, AlNb2 dispersoids as well as the Nb particles. The room temperature strength and ductility of the composites, except for the stiffness, deteriorate unexpectedly. Nonetheless, elevated temperature strength and thermal stability of the composites are improved and greater strength over that of the Al–6Ti–6Nb matrix alloy is exhibited above 240°C. The changes of the mechanical properties from room to elevated temperature are correlated with the microstructure and fractographs.

Chitosan/magnetite nanocomposite was synthesized induced by magnetic field via in situ hybridization in ambient condition. Results of XRD patterns and TEM micrographs indicated that magnetite particles with 10–20nm were dispersed in chitosan homogeneously. An interesting result is that magnetite nanoparticles were assembled to form chain-like structures under the influence of the external magnetic field, which mimics the magnetite chains inside of magnetotatic bacteria. The saturated magnetization (Ms) of nano-magnetite in chitosan was 50.54 emu/g, which is as high as 54% of bulk magnetite. The remanence (Mr) and coercivity (Hc) were 4 emu/g and14.8 Oe, respectively, which indicated that magnetite nanoparticles were superparamagnetic. The key of route is that a preprecipitated chitosan hydrogel membrane, used as chemical reactor, which controlled the precipitation of chitosan precipitation and in situ transformation of magnetite from the precursor simultaneously in the magnetic field environment.

In situ TiB whisker reinforced Ti-4.0Fe-7.3Mo matrix composites have been fabricated by spark plasma sintering (SPS). The microstructure of the in situ TiB whiskers and interfacial structures in the composites were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution electron microscopy (HREM). The interfaces between in situ TiB and the Ti matrix are clean and faceted along the (100)TiB plane. However, small lateral growth steps are observed along the (101) and (101h) planes of TiB. Because of the characteristics of the TiB crystal structure, the growing velocity of the (100)TiB plane along the [010]TiB direction is much faster than that of the [001]TiB direction, which leads to TiB growth as a whisker shape along the [010]TiB direction with a hexagonal transverse section. The growth mechanism of TiB whiskers is a stacking process of the (100)TiB plane.

Thermal analysis and Raman spectra were carried out in SrBi2Ta2O9 (SBT) nanoparticles to investigate phase transitions. Two anomalies have been observed in temperature dependence of specific heat for SBT nanoparticles. Under the combination with Raman spectra, it indicates that there exists a new ferroelectric intermediate phase in the phase-transition sequence. So we can conclude that the phase-transition sequence in SBT nanoparticles should be ferroelectric-ferroelectric-paraelectric. Moreover, the size effect was discussed in consideration of inner compressive stress in nanoparticles for this special transition behavior. The calculated results show that the SBT nanoparticles keep the ferroelectricity until the particle size is decreased to 4.2 nm.