A 59Ag.40Cu-1Hf (at.%) alloy that was heated on 99.6% alumina for 30 min at 1000degreesC in gettered Ar melted, spread, and adhered when cooled to room temperature. Conventional scanning electron microscopic analysis with energy dispersive X-ray spectroscopy (SEM/EDXS) did not detect any reaction products at the interface. Automated X-ray spectral image analysis of the interface region revealed small pockets of a phase containing Hf and O with a stoichiometry equivalent to HfO2. Samples for transmission electron microscopic (TEM) analysis were cut to include specific HfO2 particles using focused ion beam (FIB) milling. TEM images showed that the particles were 10 to 100 nm in diameter and embedded in the alumina grains at the interface with the alloy. Based on the measured stoichiometry, electron diffraction analysis in the transmission electron microscope, and a standard Gibbs energy of reaction of DeltaGdegrees = -203.3 kJ at 1300 K for the reaction 3Hf + 2Al(2)O(3) --> 3HfO(2) + 4Al, the particles are judged to be HfO2 that formed from simple redox reaction between Hf and Al2O3.