SST Technology Follow-On Program-Phase Ⅱ DEVELOPMENT AND EVALUATION OF THE ALUMINUM-BRAZED TITANIUM SYSTEM Volume Ⅳ-Material Properties

摘要

The objective of this program was to extend the useful range of structural application of aluminum-braxed titanium honeycomb sandwich panels. Flatwise tension, flatwise compression, core shear, and edgewise compression tests were conducted for various core densities, cell sizes, and core depths at test temperatures up to 1000 F. Stress-rupture characteristics of brazed joints were defined at 450 , 600, and 800 F for exposures to 19,000 hours. Factors affecting the thermal conductivity of brazed panels were determined, and the effect of the braze process on base metal fatigue properties was investigated. Results of testing and analyses show that aluminum-brazed titanium honeycomb sandwich panels have consistent material properties suitable for use in load-carrying structure. Significant findings are: (a) Useful static and sustained-load properties are realized to 800 F, with short-term strength to 1000 F; (b) Core density has greatest impact on mechanical properties; (c) Panels brazed with 3003 aluminum alloy result in design fatigue strength comparable to that for Ti-6Al-4V alloy; (d) Thermal conductivity can be effectively reduced by using core with low node density; and (e) Thermal conductivity values obtained on aluminum-brazed panels were comparable to those for welded or diffusion bonded honeycomb panels. (Author)