GB741361A - Improvements in or relating to cast molybdenum base alloys - Google Patents

Abstract

Cast Mo alloys, particularly for parts of turbo-jets, rockets, piercing points for making seamless steel tubes, electrodes for heating molten glass and dies for casting brass consist of at least 70 per cent Mo or at least 70 per cent Mo and W, with the proportion of Mo exceeding that of W, and V 0.25-7 per cent or Ta 0.5-9 per cent. or Nb 0.25-10 per cent. The alloy may also contain: Ni up to 0.4 per cent; Fe up to 13 per cent; Co up to 0.9 per cent; Cr up to 2 per cent; Th 0.01-0.5 per cent. Be up to 0.25 per cent and/or Al up to 2.5 per cent may be present in the alloy but the maximum amount of Be, in excess of 0.03 per cent, and Al, in excess of 0.4 per cent must be reduced within the range stated as the amount of each alloying transition element and W approaches its upper limit. Up to 0.05 per cent O is permissible in the alloy providing Be and/or Al is added in amounts sufficient p to react with all the O present. C up to 0.25 per cent may be present in the alloy but preferably should not exceed 0.07 per cent. The alloys may be made by mixing Mo with or without W, transition element and the other elements, if used, in the form of powders, pressing into pellets, sintering the pellets together in the form of a rod, arc melting the rod as a consumable electrode in vacuo or in an inert gas atmosphere in a closed chamber and collecting the metal in a water-cooled copper mould. Specifications 27710/10, [Class 82(i)], 652,491, [Group XXII], 656,796, 734,413, [Group XXX], 741,359 and 741,360 also are referred to.