Very little work has been done to establish the binary system. However, the general features of a tentative phase diagram are suggested in Fig. 84. Buckley and Hume-Rothery  carried out heating and cooling analyses on alloys containing 1, 5, 10 and 15 at.% Tc using 99.95% pure (BISRA “H”) iron and technetium supplied by the Oak Ridge National Laboratory. Details about its purity are not given. Great care was taken to ensure proper alloying as confirmed by autoradiographic analyses on sectioned and polished ingots.  have ascertained that Tc is extensively soluble in both γ- and δ(Fe) (see Fig.84). The addition of Tc to Fe produces very little change in the melting point (Fe m. pt. 1,535°C). The δ liquidus curve is very nearly horizontal (Fig. 85).