A further investigation on the anomaly of Ni-Cu-Zn alloys was carried out by means of electrical and dilatational measurements and X-ray analysis. The experimental results obtained are as follows. It was verified by means of electrical measurements that the structure of these alloys at high temperatures can be brought down to room temperature by rapid cooling. The change in electric resistance with progressive cold reduction of an alloy with approximate composition of Cu
2NiZn is quite abnormal. It shows initially small increase of resistance until 50% reduction, and then the resistance decreases rather rapidly, tending to 92% of the initial value. A similar change in resistance was observed by the same alloy with increasing quenching temperature. In connection with these phenomena, it may be mentioned that a remarkable increase of mean temperature coefficient (20_??_100°) of resistance due to annealing was observed with the cold drawn wire of the above mentioned alloy. So it may be concluded that the cold working of these alloys has the same effect as the quenching from a high temperature.
Of the alloys containing about 50% of Cu, the specific resistance and its mean temperature coefficient (20_??_100°) of severely cold worked wire changes continuously with increasing Ni content, but by annealing, a remarkable anomaly is observed at the approximate composition of Cu
2NiZn.
In view of the results obtained it is inferred that the so-called anomaly of Ni-silver is a kind of atomic rearrangement, and a similar effect obtainable by cold-working and quenching indicates that the nature of this anomaly is a kind of order_??_disorder change. The evidence of this assumption can be supported by anomalous contraction in dilatational measurement and heat evolution observed by thermal analysis during cooling from high temperatures. Though X-ray analysis failed to give a direct evidence of order_??_disorder change, showing only interference lines of face-centered cubic lattice, the lattice expansion corresponding to the dilatational measurement was found with the quenched alloy. In opposition to the general trend of order_??_disorder change, electric. resistance in this case increases in the disorder_??_order process, the fact of which remains yet unexplained.
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