Abstract: A heat resistant machine component, e.g. a gas turbine blade, a vane or the like, for use in a hot-gas atmosphere, especially under dynamic mechanical strain. The engine component comprises a core body consisting of a heat resistant material and a surface layer sprayed thereon and constituted by a composite material. The composite material consists on the one hand of an alloy component containing 1 to 12% Al, namely preferably 3 to 8% Al, 10 to 30% Cr, small quantities of one or more elements in the group Si, Mn, Co, Y and Hf, and the balance Fe, and on the other hand a small quantity of an oxide component containing Al.sub.2 O.sub.3 and possibly one or more oxides of the remaining metals of the alloy component, wherein the pores and the oxide component form elongated, narrow regions, which partly surround or cover the alloy component. The surface layer is applied by flame or arc spraying under a controlled minor oxidation.

Abstract: A metallic layer is applied to a substrate by flame spraying or arc spraying an alloy containing iron, chromium, and aluminum onto a substrate under conditions sufficient to produce a deposited layer containing from 10 to 30% by weight chromium, 1 to 12% by weight aluminum, 0.008 to 0.025% by weight nitrogen, 0.01 to 1.25% by weight oxygen predominantly as oxides of aluminum, iron, and chromium, with the balance substantially iron.

Abstract: A method for attaining a predetermined compressive stress is achieved by a device in the form of a washer, coating, or plug which as a function of pressure does not yield significantly, but when a predetermined pressure is reached, a sudden change in structure takes place which effects detonation of an explosive mixture which detonation is indicated by a sound, a puff of smoke, a change of appearance, a sudden release of heat, or an instantaneous increase in friction. The device includes a porous brittle body in which an explosive substance has been absorbed, and also preferably hard particles that aid in effecting detonation when the porous body goes through a physical change. The detonation can also join contact surfaces together, serve as an indication of desired prestress or torque applied to a fastener, to indicate a load limit, and the like.

Abstract: A silicon carbide body wherein the silicon carbide forms a skeleton which is pore free in itself, occupies at least 70 percent by volume of the body volume and has the intercommunicating cavities thereof filled entirely by an almost porefree molybdenum disilicide alloy.

Abstract: A heat resistant material comprising a recrystallized (self bound) skeleton of silicon carbide the pores of which are filled by infiltration of a heat resistant infiltration material, such as a silicon-molybdenum disilicide composition, so that the porosity is less than 5 % and preferably less than 2 %, the composition of the final material being such that the bending strength thereof at room temperature is at least 5 kp/mm.sup.2, and preferably above 10 kg/mm.sup.2, such as of the order of 20 kp/mm.sup.2.