Increase in resistivity of Mg-Zn alloys by low temperature aging

DOI Web Site 2 Citations 22 References

Bibliographic Information

Other Title
  • 低温時効によるＭｇ－Ｚｎ合金の比抵抗増加
  • テイオン ジコウ ニ ヨル Mg Zn ゴウキン ノ ヒ テイコウ ゾウカ

Search this article

Description

Though G.P. zone formation had been widely recognized in Mg–Zn binary alloys, there still remained some ambiguity in resistivity increase by low temperature aging. Applying the previously improved method of reliable resistivity measurement, the increase in resistivity by low temperature aging of Mg–Zn binary and ZK60 alloys was quantitatively investigated. After solution treatment at 673 K for 86.4 ks, Mg–4~10mass%Zn alloy specimens sampled from ingots were aged at low temperatures below 373 K. The resistivity increase by aging at room temperature (R.T.: about 295 K) shows a clear and very long incubation period in all alloys and does not attain the peak until 40 Ms (1.25 year) aging. In the Mg–4mass%Zn alloy, the resistivity increase is not detected by the R.T. aging till 6 Ms. Because the ZK60 alloy containing 4.84%Zn shows a slight increase from 1 Ms, the incubation period of Mg–4mass%Zn alloy may be longer than 10 Ms. The highest aging temperature at which the resistivity increase due to G.P. zone formation is observed was 333 K. Very sharp resistivity peak on isothermal aging curve accompanying with a steep decrease is quite different from that of Al–10mass%Zn alloy. Up to the resistivity peak, a tendency is confirmed that the gradient of DMR corrected Matthiessen plot is smaller than that corresponding to precipitation of transition phases. Maximum increment in resistivity from as solution treated states is large in high alloys and low aging temperatures. Using these dependences of the maximum increment on solute concentration and aging temperature, a relation between composition and aging temperature is proposed for formation limit of G.P. zone which increases the resistivity.

Journal

Citations (2)*help

See more

References(22)*help

See more

Keywords

Details 詳細情報について

Report a problem

Back to top