The effect of one-half and one atomic percent additions of iron, aluminum, silicon, and chromium on the ordering reactin of Ni₄Mo

This thesis is a continuation of research done in recent years at the University of Tennessee concerning the nature of the order-disorder reaction in the alloy Ni₄Mo. The effect of 0.5 and 1.0 atomic percent additions of Fe, Al, Si, and Cr to Ni₄Mo in which a Ni to Mo ratio of 4 four to one was maintained was studied. X-ray diffraction measurements were used to determine the long range order parameter in these alloys. Hardness measurements and metallographic studies were also made.

The four additions decreased the ordering rate slightly. An increase in the amount of the addition (from 0.5 to 1.0 %) caused a decrease in the ordering rate. The ordering rate increased for all alloys as the aging temperature was increased.