Abstract: A vacuum arc deposition device having electrode switching means comprising two or more electrodes consisting of vacuum arc vapor evaporation source materials and a substrate to which films are formed by means of vacuum arc vapor deposition, each of the electrodes and the substrate being contained in a vacuum chamber capable of introducing a reactive gas, wherein the electrodes are connected to arc discharging DC power supplies by way of polarity switching means so that each of the electrodes functions as a cathode and an anode alternately. Films, in particular, of insulative property can stably be vapor deposited on a substrate for a long period of time continuously.

Abstract: There are disclosed herein a method and an apparatus for manufacturing tubes or tubular bodies by means of hydrostatic extrusion, which tubes or tubular bodies have axially running holes therethrough having cross-sections of irregular shapes. The method and apparatus utilize a mandrel of novel construction which comprises a conical tip portion having a smooth peripheral surface, a cut or grooved intermediate portion with a sloped groove starting at a peripheral edge and a body portion formed with a flange and adapted to move longitudinally of a pressure chamber, as necessary. The conical tip portion is specifically intended to seal against the conical end of a metallic billet. Unless there is such a provision, there would be leakage of a fluid through the grooved portion because of direct contact of the grooved edge with the inner end surface of the billet.