Journal of Thermal Analysis and Calorimetry

, Volume 55, Issue 3, pp 981–987

The Detailed Mechanism of Oxidation of Ni-P Alloys

  • M. Wierzbicka
  • A. Malecki
Article

DOI: 10.1023/A:1010106506249

Cite this article as:
Wierzbicka, M. & Malecki, A. Journal of Thermal Analysis and Calorimetry (1999) 55: 981. doi:10.1023/A:1010106506249

Abstract

DTA in conjuction with X-ray diffraction analysis with a high-temperature camera and infrared spectroscopy was employed to determine the mechanism of oxidation of Ni-P alloys. Amorphous Ni-P powders were obtained from a nickel(II) sulphate bath as a nickel source and sodium dihydrophosphate(I) as a reducing agent. The crystallization product is composed of two phases: (f.c.c.) Ni and (b.c.t.) Ni3P. The amorphous to crystalline transformation takes place in the temperature range 280–330°C. Ni3P samples were heated from room temperature to 1050°C in air atmosphere at 5°C min−1. It was found that the first stage of oxidation of Ni3P goes through the intermediate phase of Ni12P5 formation to Ni2P. Some exothermic reactions were observed. Heating runs were interrupted after each reaction for crystal structure determination by IR spectrometry. Infrared spectra are reported and it is shown that the structure units present in the amorphous products at about 700°C were the oxoanions PO3 and P2O7. The final products of the oxidation process are NiO and Ni3(PO4)2.

nickel phosphates nickel phosphides Ni-P alloys oxidation 

Copyright information

© Kluwer Academic Publishers 1999

Authors and Affiliations

  • M. Wierzbicka
    • 1
  • A. Malecki
    • 1
  1. 1.Faculty of Material ScienceUniversity of Mining and MetallurgyCracowPoland

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