Environmental Durability Testing of Structural Adhesives. Part II. BR- 127/FM-123
Abstract
A program has been conducted to investigate the durability of a 250 F (121 C) curing modified epoxy structural adhesive in an elevated temperature, high humidity environment while under stress. The results indicated that, for shear stress levels low enough to preclude fracture of the adherend surface oxide layer (below 2000 psi (13.9 MPa)), the FM-123-2/BR-127 adhesive/primer system provides long-term durability at 120 F (49 C) and 95-100% R.H. on both phosphoric acid anodized (PAA) and optimized Forest Products Laboratory (OFPL) etched surfaces. The change in slope of the environmental stress-rupture time- to-failure curve for the PAA specimens seems to correlate well with the stress level at which oxide fracture would be expected to occur (about 3000 psi (20.65 MPa)) and may indicate a different degradation mechanism above this stress level than below. The effect of temperature upon the durability of the adhesive joints tested in this investigation is to reduce durability with increasing temperature, as was to be expected. At higher aging temperatures, the interface seems to be more susceptible to degradation than the adhesive, while at lower temperatures the reverse is true.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1978
- Accession Number
- ADA068379
Entities
People
- D. Robert Askins
Organizations
- University of Dayton