GB419953A - Manufacture of nickel iron alloys - Google Patents

Abstract

In the preparation of nickel-iron alloys an intimate mixture of iron and nickel oxalates are produced by precipitating them from a solution containing soluble ferrous and nickel salts by the addition of a soluble oxalate such as ammonium oxalates, filtering off the precipitate washing it with water until free from contaminating salts and then drying. The precipitation is carried out at boiling point to obtain the precipitate in a readily filterable condition. The oxalate of copper or cobalt when the latter elements are to be incorporated in the alloy are produced by co-precipitation with the iron and nickel oxalate.ALSO:Nickel-iron alloys in powder form are produced by subjecting a mixture of the oxalates of the metals to heat in a reducing atmosphere until reduction is complete and then increasing the temperature used until it is sufficient finally to homogenize the alloys. The mixture may be heated first in an inert atmosphere such as nitrogen until the decomposition of the oxalates is complete before heating in the reducing atmosphere, such as hydrogen. Additional metals, such as cobalt, copper, or molybdenum, may be incorporated in the alloys by adding to the mixture an oxalate of the said metals or when such metals do not yield an oxalate, an oxide reducible by hydrogen. The intimate mixture of the iron and nickel oxalates is obtained by precipitating them from a solution containing soluble ferrous and nickel salts by the addition of a soluble oxalate such as ammonium oxalate, filtering off the precipitate washing it with water until free from contaminating salts and then drying. The precipitation is carried out at boiling point to obtain the precipitate in a readily filterable condition. The preparation of alloys containing 43,5 per cent of nickel, 43,5 of iron, 8,6 of copper and 4,4 of molybdenum, and 45 of iron, 45 of nickel and 10 of copper is referred to.