PREPARATION OF PALLADIUM-BASED ALLOY POWDERS BY THE THERMAL-DECOMPOSITION OF BINARY COMPLEX AMMONIUM OXALATE SALTS

The possibility of obtaining powder alloys (solid solutions) by therma l decomposition of salts of rite types [Pd(NH3)4[M(C2O4)(2)] and [M(NH 3)n][Pd(C2O4)(2)] was investigated. Salts of the desired compositions were synthesized by double decomposition of the ammonium and oxalate c omplexes of tile metals in aqueous solution. The production of new com pounds was confirmed by x-ray diffraction analysis. it was shown that pyrolysis of the salts [Pd(NH3)(4)][M(C2O4)(2)] occurs in stages: init ially one of the oxalate groups migrates to the cationic part, and lat er the products obtained, [Pd(NH3)(2)](C2O4)] and MC(2)O(4), decompose . The decomposition temperatures of the salts obtained correlated with those of MC(2)O(4). Pyrolysis of [Pd(NH3)(4)].[M(C2O4)(2)] produced h ighly dispersed solid solution powders of palladium with copper, nicke l, and copper, respectively, with the atom ratio Pd:M similar or equal to 1:1, and the intermetallic compound PdZn. The powder particle size s did not exceed 1 mu m. Initial salts, intermediate products, and oxi des were not detected in the powders.