The inner surface of the hydrostatic bearing was coated with the white metal by plasma irradiation on the inner surface. Since the ratio of elemental components in the thermal sprayed coating changes due to the high temperature during thermal spraying, it is necessary to optimize the component ratio of the sprayed raw material in advance. In addition to these examples, this description also describes the analysis and the evaluation methods of coating.

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Thermal spray coatings generally contain defects such as voids and oxides. After thermal spraying, Ni self-fluxing alloys can be fused at a temperature above the solidus, making use of the liquid phase to improve coating defects. However, the fusing temperature of this material is generally 1000 to 1100℃, so there are concerns about deformation and deterioration of the properties of the steel base material. Furthermore, the high temperature operation of the fusing furnace consumes a lot of fuel (such as heavy oil) , which places a heavy burden on the environment. In Ni-B-Si compositions, it is possible to lower the liquidus. On the other hand, a significant lowering of the solidus is not expected. In this study, we focused on P, which has a low eutectic temperature with Ni of 870℃ , and investigated a composition based on SFNi4 in which part of B and Si were replaced with P. As a result, we succeeded in significantly lowering the solidus temperature.

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Mo₂FeB₂ and Mo₂NiB₂ boride base cermets, which consist of the boride phase and the Fe or Ni base binder phase, have had good mechanical properties, excellent corrosion and wear resistance and have been applied to plastic injection molding machine parts such as cylinders and screws. At present, however, these product sizes are limited by their low machinability. Therefore, we have developed a self-fluxing alloy spray coating method for these cermets, which makes possible to form the cermet layer easily on large-sized and complicated-shaped substrates.
In this paper, in order to investigate the suitable conditions of granulated powder heat treatment and fusing treatment of thermal spray material prepared as the specimens for spray coating, hardness and microstructures were studied. The powder was manufactured by the granulation-sintering method.
The microstructure of thermal spray coating layer became dense with increasing heat treatment temperature of the granulated powders, it was considered that this phenomenon was influenced by denseness of thermal spray powders. In the fusing process, the hardness increased with rising the fusing temperature and showed the highest values of about 1350HV at 1210℃ or 1220℃, and then decreased with rising the temperature.

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In the cold spray method, the coatings are formed by shear deformation of particles. The heat-treated powder has a reduced particle compressive strength, and cold spraying with this powder improves deposition efficiency. Heat-treating the powder causes the crystal grains to coarsen and the microstructure to become homogenous, reducing the particle compressive strength. By using a method of heat-treating the powder, it was possible to fabricate dense coatings from the high-strength brass powder.

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Several Japan's infrastructure facilities are degrading with time. These facilities need to be efficiently maintained in a good condition by implementing appropriate maintenance and introducing various techniques. This paper concentrates on the application of cathodic protection for repairing concrete structures and the cathodic protection system of titanium thermal spray. The titanium spray coating conducts as an anode that provides the protective current to the reinforcing steels. The reinforcing steels control corrosion condition by receiving the protective current. The mechanism of cathodic protection and the application of titanium thermal spraying method were summarized.

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