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Title: High temperature stability, interface bonding, and mechanical behavior in [beta]-NiAl and Ni[sub 3]Al matrix composites with reinforcements modified by ion beam enhanced deposition

Technical Report ·
DOI:https://doi.org/10.2172/6583595· OSTI ID:6583595

Diffusion-bonded NiAl-Al[sub 2]O[sub 3] and Ni[sub 3]Al-Al[sub 2]O[sub 3] couples were thermally fatigued at 900 C for 1500 and 3500 cycles. The fiber-matrix interface weakened after 3500 cycles for the Saphikon fibers, while the Altex, PRD-166, and FP fibers showed little, if any, degradation. Diffusion bonding of fibers to Nb matrix is being studied. Coating the fibers slightly increases the tensile strength and has a rule-of-mixtures effect on elastic modulus. Push-out tests on Sumitomo and FP fibers in Ni aluminide matrices were repeated. Al[sub 2]O[sub 3] was evaporated directly from pure oxide rod onto acoustically levitated Si carbide particles, using a down-firing, rod-fed electron beam hearth; superior coatings were subsequently produced using concurrent irradiation with 200-eV argon ion-assist beam. The assist beam produced adherent films with reduced tensile stresses. In diffusion bonding in B-doped Ni[sub 3]Al matrices subjected to compressive bonding at 40 MPa at 1100 C for 1 hr, the diffusion barriers failed to prevent catastrophic particle- matrix reaction, probably because of inadequate film quality. AlN coatings are currently being experimented with, produced by both reactive evaporation and by N[sup +]-ion enhanced deposition. A 3-kW rod-fed electron-beam-heated evaporation source has been brought into operation.

Research Organization:
Michigan State Univ., East Lansing, MI (United States). Dept. of Metallurgy, Mechanics and Material Science
Sponsoring Organization:
USDOE; USDOE, Washington, DC (United States)
DOE Contract Number:
FG02-85ER45205
OSTI ID:
6583595
Report Number(s):
DOE/ER/45205-8; ON: DE93013977
Country of Publication:
United States
Language:
English