Abstract: Particles such as magnetic iron oxide capable of being magnetized are crushed to obtain minute magnetic particles each size of which is not larger than 10 .mu.m. The minute magnetic particles are mixed as they are dispersed with such a binding material as cobalt or nickel. Thermal spraying particles each size of which is not smaller than 10 .mu.m are obtained from the mixture. Then, the thermal spraying particles are sprayed upon such a member as a turbine shaft to form a magnetic film on the member with plasma spraying method.

Abstract: A pair of magnetic recording parts are axially spaced on a rotating shaft and a pair of magnetic heads for recording and reproducing a location signal are respectively opposed to the respective magnetic recording parts. Torque of the rotating shaft is calculated based on a quantity of a phase shift of the location signals reproduced by the respective magnetic heads and rotating speed of the rotating shaft is calculated based on a reproducing frequency of the location signal reproduced by one of the magnetic heads so that the magnetic recording parts and the magnetic heads serves as a sensor for detecting both torque and rotating speed. Thus, a number of parts of the sensor is lessened, being compacted with low cost.

Abstract: A magnetic film for recording a magnetic signal is formed on a surface of a base piece. The magnetic film contains Fe.sub.3 O.sub.4 of at least 30 wt %, preferably at least 75 wt %. For forming the magnetic film, a plasma spraying method is employed, in which an iron oxide (FeOx) is used for a thermal spraying powder, and a non-reducing gas is used as a working medium for the plasma spraying.

Abstract: Powder which has primary particle size of not larger than 10 .mu.m and is formed of mixture of Ni powder and Cr powder added with hard particles containing carbide is mixed with Cr.sub.3 C.sub.2 powder and granulated and sintered, whereby flame spraying powder having secondary particle size of 5 to 53 .mu.m is formed. The flame spraying powder thus formed is flame-sprayed under conditions which will cause fused Ni.Cr to cover Cr.sub.3 C.sub.2 particles which are not fused, thereby binding the Cr.sub.3 C.sub.2 particles and causes the thickness of one Ni.Cr layer to be smaller than 5 .mu.m. In this manner, flame spray coating the porosity of which is not larger than 2% and the hardness of which is not lower than 700 (Hv: 200 g) can be obtained.

Abstract: A process for forming a sintered layer on a substrate of an iron-based material containing carbon. A sheet of powders of an alloy is prepared by mixing the powders with a solution of resin and rolling the mixture into a sheet. The sheet is then heated to a sintering temperature. In order to prevent carbon content in the substrate from diffusing to the powder sheet during the sintering process, a lamina is provided beneath the powder sheet for example by a metal plating, a metal oxide layer, an intermediate alloy powder sheet, a decarbonized layer.

Abstract: A process of forming a high alloy layer on a surface of an aluminum alloy casting. The process comprises steps of providing a mixture of fine powders having an average powder size finer than 10 microns, preferably finer than 1.0 micron, of an alloying metal or an alloying alloy and an acrylic binder, shaping the mixture into a sheet, heat treating the sheet at 150.degree. to 380.degree. C. for more than 5 minutes, placing the heat treated sheet on a surface of a casting mould or a chilling block, and casting molten aluminum alloy.

Abstract: A process for forming a wear-resistant, sintered layer on an iron based substrate which comprises steps of providing a first alloy sheet containing 94 to 99 weight % of Fe-Cr type alloy particles and 6 to 1 weight % of acryl binder and a second alloy sheet containing 94 to 99 weight % of eutectic alloy particles and 6 to 1 weight % of acryl binder, placing the first and second alloy sheets in a superposed condition on the substrate, and heating in a non-oxidating atmosphere to a temperature which is higher than a solidus temperature of the eutectic alloy but lower than a solidus temperature of the Fe-Cr type alloy.

Abstract: A method for sealing porous metals, which comprises applying powder of a eutectic alloy containing an element having a good diffusibility in a porous metal or powder of a mixture of metals capable of forming the eutectic alloy, to the surface of a porous metal member and heating the surface applied with the powder at a temperature higher than the eutectic temperature of the eutectic alloy to thereby cause the molten eutectic alloy to intrude into pores from the surface of the porous metal member, whereby the melting point of the molten alloy in the pores is promptly increased by diffusion of the element in the porous metal member to solidify the molten metal in the pores, sealing only pores present in the vicinity of the surface of the porous metal member.