Abstract: The invention provides an aluminum base bearing alloy which is excellent in both lubricating capability and fatigue resistance and is useful, e.g. in automotive engines. The bearing alloy consists essentially of at least one lubricating element such as Pb and/or Sn the total amount of which is more than 0.04 and not more than 0.07 by sectional area ratio to the aluminum matrix, Si the amount of which is in the range from 0.01 to 0.17 by sectional area ratio to the aluminum matrix, 0.2-5.0 wt % of at least one reinforcing element such as Cu and/or Cr, 0-3.0 wt % of at least one refining element such as Ti and/or B and the balance of Al. The grain size of the lubricating element(s) is not larger than 8 .mu.m, and the grain size of Si is not larger than 12 .mu.m and preferably not smaller than 6 .mu.m.

Abstract: A welding wire for automatic arc welding, which is particularly suitable for use in build-up welding operation for the purpose of providing hard surface to a metal die. The welding wire consists of a continuous tubular metal casing and a core composition charged in the interior of the casing and comprises such amounts of Ni, Si, B, Nb and C as essential alloying elements that the deposited metal contains at least 40% of Ni, 3-8% of Si, 0.1-0.4% of B, 0.3-1.8% of Nb and 0.2-1.5% of C, all by weight. Preferably, either a practically pure Ni strip or an Fe-Ni alloy strip is used as the material of the casing, and the core composition in the form of a powder mixture contains necessary amounts of Ni, Si, B, Nb and C, optionally with the addition of a small amount of Zr. The deposited metal given by this welding wire has high wear resistance and good antifrictional property and seldom suffers from weld cracks.

Abstract: A covered electrode for shielded metal arc welding, which is particularly suitable for use in build-up welding operation for the purpose of providing hard surface to a metal die. The covered electrode comprises such amounts of Ni, Si, B, Nb, C and Zr as essential alloying elements that the deposited metal contains at least 40% of Ni, 3-8% of Si, 0.1-0.5% of B, 0.3-2.0% of Nb, 0.2-1.5% of C and 0.01-0.20% of Zr, all by weight. In a preferred form, either Ni wire or Fe--Ni wire is used as the core wire, and the covering contains necessary amounts of all the essential alloying elements except Ni. The deposited metal has high wear resistance and good antifrictional property, and the presence of Zr is highly effective for preventing the occurrence of weld cracks.

Abstract: A porous coating, which is effective in restricting the flow of a gas under measurement relatively to the electrode layer of the sensor and protecting the electrode against detrimental influences, is formed by spraying fine particles of a heat-resistant and chemically stable material at a high temperature onto the electrode surface to form a porous layer with pores of a moderate size, then impregnating the porous layer with an aqueous dispersion of fine particles of a similar material followed by baking the impregnated layer, so that the finished coating has pores of appropriate size and total volume.

Abstract: A low wear coating formed on a metal substrate to serve as a high temperature rubbing seal layer, comprising a surface layer made fundamentally of a wear resistant metal oxide such as nickel oxide and a solid lubricating material such as calcium fluoride and at least one intermediate layer made fundamentally of the metal oxide optionally with the addition of the lubricating material, wherein at least an outmost intermediate layer as well as an inmost region of the surface layer is impregnated with a brazing solder. The solder is added in the form of powder to the material of the intermediate layer prior to a flame spraying process and later caused to melt and permeate into the surface layer formed by flame spraying.

Abstract: A member including a metal substrate, a low wear coating formed by flame spraying a mixture of a wear resistant metal oxide such as nickel oxide and a solid lubricating material such as calcium fluoride to serve as a high temperature rubbing contact seal layer and at least one undercoat layer formed by flame spraying between the substrate and the surface layer, characterized by the presence of a metal in at least one of the undercoat layers mixed with a commonly employed fundamental material, which is the wear resistant metal oxide optionally with the addition of the solid lubricating material, in order to lessen the difference in thermal expansion coefficient between the individual undercoat layer and the surface layer.

Abstract: In an oxygen sensor having a solid electrolyte layer such as stabilized zirconia and two electrode layers form respectively on both sides of the electrolyte layer, at least one electrode which is to be exposed to a gas mixture subject to measurement is made of carbon silicide to avoid catalyzing oxidation reactions, optionally with the addition of a minor amount of trisilicon tetranitride as a binder. The sensor features an exact and noticeable dependence of its output voltage on the oxygen concentration in a gas mixture in a non-equilibrated state as typified by an engine exhaust gas.