[en] Molybdenum disilicide (MoSi₂) with or without La₂O₃ particles were synthesized by mechanical alloying (MA) and HP techniques. The fracture toughness at room temperature was measured by Anstis' mode and the responded microstructures were analyzed by using SEM and X-ray. The results show that the addition of La₂O₃ could obviously toughen the matrix. When the content of La₂O₃ in MoSi₂ is about 0.9%, the fracture toughness value increases by about 50% more than that of pure MoSi₂. We think, the corresponding toughening mechanisms depend on the following: fine-grain, microcracking, crack deflection, crack microbridging, crack bowing and branching

[en] The microstructure of the films deposited ZrO₂-Y₂O₃ by Ar² ion irradiation are investigated with XRD, AES and XPS. The results show that amorphous films deposited with r.f. magnetron sputtering at room temperature are transformed partly to crystalline after argon ion irradiation. The irradiated films are obviously mixed with substrate and contaminating carbon enters the films deeply. Besides, Zr(3d), Y(3d) and O(1s) on the surface of the deposited films are studied before and after argon ion irradiation

[en] ZrO₂ films on NaCl(100) substrate produced by oxygen ion bombardment and argon ion sputtering Zr are analysed using TEM, XRD and XPS. The result of TEM shows that only cubic phase exists in the ZrO₂ film produced by oxygen ion bombardment with 30 μA/cm² and 200 eV, while the XRD result shows that there seems to exhibit a small quantity of monoclinic phase apart from cubic one under the production condition of oxygen ion of 25 μA/cm², 100 eV

[en] The r.f. magnetron sputtering deposited C-SiC coatings on stainless steel surface are micro analysed by XRD and XPS before and after electron beam treatment, and the results are discussed

[en] The ZrO₂ ·Y₂O₃-NiCoCrAlY thermal barrier coatings (TBC) deposited with the combined ion-electron-atom beams technique were oxidized at 1100 degree C for 70 h. The SEM-EDAX and XPS micro-analyses were carried out for these specimens before and after the oxidation in order to study the elemental distribution of the coatings and the chemical states of these elements. Some related phenomena were discussed

[en] XPS was used to measure the elements in the ion beam mixing deposited tungsten films on stainless steel substrates before and after H⁺ ion irradiation. The effect of H⁺ ion irradiation on the binding energy of the element tungsten and tungsten oxides in the deposited tungsten films was investigated. The experiment results show that the binding energy of one part of tungsten component shifted to the lower side due to H⁺ ion irradiation. It is found that the content of the tungsten oxides in the film was reduced by preferential oxygen sputtering after H⁺ ion irradiation

[en] Tungsten films with different thickness were deposited by ion beam mixing techniques on the austenitic stainless steel. Microanalyses of XRD and SEM were measured for the deposited tungsten films before and after H⁺ ion irradiation. The effect of the morphology and phase structure of the tungsten films by H⁺ ion irradiation was studied. The results showed that the deposited tungsten films were nearly amorphous, and tungsten oxides were found due to the contamination of oxygen before H⁺ ion irradiation. Simulation of H⁺ ion irradiation on these films showed that a little crystalline tungsten was gradually transformed into amorphous and the contamination of WO₃ was significantly reduced by preferential oxygen sputtering. There is little difference between surface morphologies of tungsten films before and after H⁺ ion irradiation. Tungsten films surfaces still showed dense, uniform, complete and no obvious damages after H⁺ ion irradiation

[en] The zirconia containing 12wt%Y₂O₃ thin films deposited by r.f. magnetron sputtering at 25 degree C or 400 degree C, and then bombarded with Ar⁺ beam at room temperature were characterized with XRD before and after Ar⁺ bombardment. It is found that a series of phases formation and transformation happened, among them the most important event is that T' phase appeared after Ar⁺ irradiation and the content of the T' phase increased with the increase of Ar⁺ ion doses from 5 x 10¹⁵ to 6 x 10¹⁶ ions cm^-2

[en] An enriched nitrogen layer on the surface of high speed steel W18Cr4V was formed by nitrogen ion implantation. In the X-ray photoelectron spectroscopy of the layer the Fe₂N and Fe₄N phases with high hardness were found. The microhardness and wear resistance of the high speed W18Cr4V were increased. In industrial production the wear resistance and durability of the ion implantation cutting tools were doubled. Owing to the implantation the improvement in druability of a cutting tool can last for its whole service life. The ion implantation technique has good prospects in application to cutting tools

[en] A traditional preparation process of Mo powder is generally time-consuming and leads to coarse particles. In this work, we propose a short-flow strategy, in which the intermediate product of MoO₂ is prepared by a one-step self-reduction method in air instead of a mixture of decomposition and hydrogen reduction processes. And the reaction mechanism of self-reduction is investigated and the consequent sintering performance of Mo powder is also compared with the traditional one. The obtained results demonstrate that the finally synthesized Mo–La₂O₃ powder prepared by the self-reduction strategy are spherical with an average particle size of 2.03 μm, exhibiting an excellent sintering performance with a relative density of 95.3% and a hardness of 260.6 (HV), better than those by a traditional one (93.4% and 232.4 (HV)), which can be attributed to smaller particle size and better shapes. This work provides a new route for the synthesis of Mo–La₂O₃ powder, indicating a possible industrial application. (paper)