Titanium Braze System for High Temperature Applications.
Abstract
This report describes the design rationale and development of special, high-temperature braze systems for joining titanium and titanium alloys, suitable for long term aerospace application to 800 F. Candidate braze alloy designs were substrate-compatible, low-melting (1650-1750 F) compositions within the metallurgically similar Ti, Zr-, Ti-Zr, Ti-V, and Zr-V-Ti (base) systems. Best results were obtained with the Ti-Zr system. Desired hypoeutectic structure and melt-solidification behavior were achieved wherever possible through controlled reduction of major melting-point depressants and/or Zr/Ti ratios, backing-off from eutectic alloying levels. Principal alloying objectives were (a) braze strength, toughness and ductilT:y properties (RT-800 F) comparable to the high-melting TI-15Cu-15Ni baseline braze alloy, (b) conventional brazing characteristics superior to the baseline braze, particularly brazing capability < or = 1750 F to avoid 'beta embrittlement' of the substrate (Ti-6Al-4V) and (c) intrinsic long-term resistance to structural damage from aqueous salt spray, 800 F air oxidation, and 800 F hot-salt corrosion. Over 350 different braze alloy designs were evaluated through various screening tests. The two braze alloy designs which best met program objectives are designated AC5-16 (Ti-27.2Zr-15.ONi-7.OCu) and AC1-20 (Ti-28.8Zr-28.OCu). The principal substrate alloy employed was Ti-6Al-4V; some comparison tests were conducted wITh Beta-C substrate alloy.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1976
- Accession Number
- ADA036575
Entities
People
- A. N. Hammer
- C. E. Smeltzer