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The microstructure evolution laws of ultrafine grained metastable automobile steels was studied in this paper by laser confocal scanning microscope, EBSD, XRD and TEM. Results showed that, the matrix organizations of hot-rolled steel were lath martensite and deformation ferrite, and there were a little of retained austenite film and lath between the lath martensite. After heat treatment, the matrix organizations of steel were ultrafine ferrite and retained austenite. The retained austenite transformed into martensite and ε-martensitic in the deformation process, and the strength and plasticity of steel were improved. A lot of retained austenite were obtained in the annealing process. The TRIP effects by the large fraction of metastable austenite and the ultrafine grain size add to the test steel with high strength and high plasticity.

Boron doped diamond (BDD) films were deposited on porous Ti substrates by direct current plasma chemical vapor deposition (DC-PCVD) system. For improve adhesion between diamond and porous Ti, and shorten diamond nucleation period, appropriate pretreatments were carried out. Micro diamond particles were mechanical embedded in the holes of porous Ti substrates and then nanodiamond powders were seeded on substrates by ultrasound sonication prior to deposition. The samples were examined by scanning electron microscopy (SEM), micro-Raman spectroscopy, and cyclic voltammetry. It was found that BDD films covered the whole porous Ti substrate surface, and exhibited the good electrochemical property.

In this study we report on the synthesis and characterization of thermally stable polycrystalline diamond (PCD) using Ni-based alloys catalyst as a sintering aid and the B-doped diamond powder in the infiltrating way. The samples were treated at 5.6 GPa and 1200–1480 °C for 10 min in China-type cubic high pressure apparatus. Scanning electron microscopy showed significant intergrowth of the diamond particles sintered in the presence of Ni-based alloy. X-ray diffraction showed the phase change of the samples sintered at the different temperature. Differential thermal analysis (DTA) and thermogravimetric analysis (TG) showed the sample was significantly more heat-resisting compared to conventional PCD. The results showed that the appropriate conditions of thermally stable PCD sintered were 5.6GPa and 1200–1480 °C.

In this paper, industrial diamonds using FeNi powder catalyst with additive La2O3 has been synthesized by HPHT method. Optical microscope, XRD and SEM were utilized for observation and detection. The influences of additive La2O3 on the synthesis have been investigated from several aspects such as the diamond-forming conditions, the composition of synthesized sample and inclusions in diamond, and the morphology character of diamonds etc. The results indicate that There is a new compound LaO, LaFeO3, Fe3C and Fe3O4 in the sample., and related phenomena were given in detail in this paper.

Synthesis of Ⅱa industrial diamond with high quality at high temperature and high pressure (HTHP) was examined in this paper and Ⅱa industrial diamonds were synthesized successfully. The experimental results show that the lowest synthesis pressure of diamond changed significantly which goes down firstly, and then up with the increasing of Ti content. It is discovered by optical microscopy that the color of synthesizing diamond in nitrogen getter system is lighter than that in raw catalyst power system and most crystals are hexahedrons & octahedrons. The experiment results measured by IR analysis shows that nitrogen content in synthesizing diamond in nitrogen getter system is significantly lower than that in the raw catalyst power system. Surface morphology of diamond synthesized in two different systems is investigated by the aid of SEM.

In this paper, industrial diamonds using pure Fe powder catalyst with additive Si has been synthesized by HPHT method. Optical microscope, XRD and SEM were utilized for observation and detection. The influences of additive Si on the synthesis have been investigated from several aspects such as the diamond-forming conditions, the composition of synthesized sample and inclusions in diamond, and the morphology character of diamonds etc. The results indicate that the formation of SiC, which should have been in a solid state during the synthesis.

A number of studies have shown that TiN film is correlated with corrosion resistance. In this study, we used a reactive direct current magnetron sputtering system to prepare TiN coating on Mg-Li alloys at low temperature. The intermediate TiN layer of thickness was about 1.6 μm from Ti target (99.99% purity). The structures of the resulting nanocatalysts were investigated, using X-ray diffraction analysis (XRD). The surface morphology of the coating was observed by Atomic Force Microscope (AFM). In the corrosive compare experiment the samples of Mg-Li alloys with and without titanium nitride film were put in solution with 5% NaCl respectively. We fund that the Mg-Li alloys with TiN coating has a lower rate of liberation of hydrogen, and the eroded surface morphology was examined by Scanning Electron Microscopy (SEM), it prove that the TiN deposition on the surface of Mg-Li alloys has improved the corrosion resistance performance.