Author/Authors :
Akinc، نويسنده , , Mufit and Meyer، نويسنده , , Mitchell K. and Kramer، نويسنده , , Matthew J. and Thom، نويسنده , , Andrew J. and Huebsch، نويسنده , , Jesse J. and Cook، نويسنده , , Bruce، نويسنده ,
Abstract :
The addition of as little as 1 wt.% (=3 at.%) boron improved the oxidation resistance of Mo5Si3 by as much as five orders of magnitude over a temperature range of 800–1500°C. The mechanism of oxidation protection is the formation of a borosilicate glass scale that flows to form a passivating layer over the base intermetallic. The compositional homogeneity range for T1 (Mo5Si3Bx) phase was determined to be much smaller than that reported previously by Nowotny. Compressive creep measurements show that materials based on the phase assemblage of T1-T2 (Mo5SiB2)–Mo3Si have high creep strengths similar to single phase Mo5Si3. Electrical resistivity of selected compositions was also measured and varied from ≈0.06 mΩ-cm at room temperature to 0.14 mΩ-cm at 1500°C. Temperature coefficient of resistivity (TCR) was estimated to be on the order of 1×10−4 C−1 for most compositions.
