THE NICKEL-PLUTONIUM SYSTEM

A tentative nickel-plutoniuni constitutional diagram was based on data obtained by thermal analysis, metallography, and x-ray-diifraction techniques. The systema is a complex one with the following important features. Nickel is soluble in epsilon plutonium, extending the epsilon field to 4.3 at.% nickel at 465 deg C. Nickel and plutonium form six intermetallic compounds, PuNi, EnNi/sub 2/, PuNi/sub 3/, PuNi/sub 4/, PuNi/sub 5/, and PuNi/sub 9/. The compound PuNi/ sub 5/ forms congruently from the melt at approximately l300 deg C, whereas the other compounds forma peritecticaliy. The extended epsilon field termainates in a eutectoid reactlon at 415 deg C and l.5 at.% nickel. Epsilon plutonium and the compound PuNi form a eutectic system at 465 deg C with a eutectic compcsition of l2.5 at,% nickel. Nickel and the compound PuNi/sub 9/ form a eutectic system at l2l0 deg C with a eutectic composition of 92 at.% nickel. Plutonium forms a limited solid solution with nickel. (auth