Published February 1996 | Version v1
Journal article

Effect of niobia as an additive in phosphate-bonded alumina

  • 1. Univ. Federal de Sao Carlos, Sao Paulo (Brazil). Dept. de Engenharia de Materiais
  • 2. Univ. de Sao Paulo, Sao Carlos, Sao Paulo (Brazil)

Description

In this work a study was carried out on the Al2O3/Nb2O5/H3PO4 system. A-2 alumina from Alcoa (Brazil) was used and the Al2O3/Nb2O5/H3PO4 system with an Al2O3/P2O5 molar ratio of 20.3, pressed at 20 and 60 MPa and thermally treated at 110, 300, 500, 800, 1,000, 1,200, 1,400 and 1,600 C, was studied. An attempt was made to relate mechanical properties with porosity as well as with the phases formed during heat treatment. X-ray diffraction (XRD), infrared spectroscopy (IRS) and magic-angle spinning phosphorus nuclear magnetic resonance (31P MAS NMR) were used for phase detection. The amorphous AlPO4 was considered as the low temperature bonding phase. The system studied showed highest mechanical strength at 1,400 C

Additional details

Publishing Information

Journal Title
Materials Research Bulletin
Journal Volume
31
Journal Issue
2
Journal Page Range
p. 235-244.
ISSN
0025-5408
CODEN
MRBUAC