A [3-t-Bu-2-OAC 6 H 3 CH@N(C 6 F 5 )] 2 TiCl 2 catalyst (bis(phenoxyimine)titanium dichloride complex -FI catalyst) was immobilized on disilanolisobutyl polyhedral oligomeric silsesquioxane (OH-POSS) to prepare ultrahigh molecular-weight polyethylene (UHMWPE)/polyhedral oligomeric silsesquioxane (POSS) nanocomposites during ethylene in situ polymerization. The dispersion state of POSS in the UHMWPE matrix was characterized by X-ray diffraction measurements and transmission electron microscopy. It was shown that the OH-POSS achieved uniformed dispersion in the UHMWPE matrix, although its polarity was unmatched. The isothermal and nonisothermal crystallization behavior of the nanocomposites was investigated by means of differential scanning calorimetry. The crystallization rate of the nanocomposites was enhanced because of the incorporation of POSS during the isothermal crystallization. POSS acted as a nucleus for the initial nucleation and the subsequent growth of the crystallites. For nonisothermal studies, POSS showed an increase in the crystallinity. The crystallization rate of the nanocomposites decreased because the presence of POSS hindered the crystal growth.

A self-designed Ti-35421 (Ti-3Al-5Mo-4Cr-2Zr-1Fe wt%) titanium alloy is a new type of low-cost high strength titanium alloy. In order to understand the hot deformation behavior of Ti-35421 alloy, isothermal compression tests were carried out under a deformation temperature range of 750–930 °C with a strain rate range of 0.01–10 s−1 in this study. Electron backscatter diffraction (EBSD) was used to characterize the microstructure prior to and post hot deformation. The results show that the stress–strain curves have obvious yielding behavior at a high strain rate (>0.1 s−1). As the deformation temperature increases and the strain rate decreases, the α phase content gradually decreases in the α + β phase region. Meanwhile, spheroidization and precipitation of α phase are prone to occur in the α + β phase region. From the EBSD analysis, the volume fraction of recrystallized grains was very low, so dynamic recovery (DRV) is the dominant deformation mechanism of Ti-35421 alloy. In addition to DRV, Ti-35421 alloy is more likely to occur in continuous dynamic recrystallization (CDRX) than discontinuous dynamic recrystallization (DDRX).

The isothermal hot compression behavior of new Ti–Fe–B (named as TF400) alloy was investigated in the temperature range of 750–950 °C and strain rate range from 0.01 to 10 s−1 with the maximum height reduction of 60% by using a Gleeble 3800 thermal simulator. By considering the effect of strain via variable material parameters, a modified constitutive model was proposed to accurately predict the flow stress. The predicted results demonstrate that the flow stress decreases with the increase of temperature while it increases as the strain rate increases, in good agreement with the present experimental results. A mechanistic understanding of plastic deformation behavior in the TF400 alloys was developed by inspecting the microstructural characteristics prior to and after deformations. Dynamic recrystallization and dynamic transformation were found to be the dominant restoration mechanism during the hot deformation process.

In this work, the evolution of the solidification microstructures of Ti–6Al–4V–xFe (x = 0.1, 0.3, 0.5, 0.7, 0.9) alloys fabricated by levitation melting was studied by combined simulative and experimental methods. The growth of grains as well as the composition distribution mechanisms during the solidification process of the alloy are discussed. The segregation of the Fe element at the grain boundaries promotes the formation of a local composition supercooling zone, thus inhibiting the mobility of the solid–liquid interface and making it easier for the grains to grow into dendrites. With the increase in Fe content, the grain size of the alloy decreased gradually, while the overall decreasing trend was mitigated. The segregation of Fe was more obvious than that of Al and V, and the increase in Fe content had less effect on the segregation of Al and V.