Engineering topics
Publications and source records attributed to Ecklund, R. C..
Potential tooling pickup not acceptable on sandwich panels that have face sheets 0.016 in. (0.41 mm) thick. In this application, problem eliminated by changing tooling slipsheet from type 321 CRES to type 430 stainless steel and coating both slipsheet and face sheet with boron nitride powder and binder thinned in acetone.
The feasibility of applying superplastic forming/diffusion bonding (SPF/DB) technology to laminar flow control (LFC) system concepts was demonstrated. Procedures were developed to produce smooth, flat titanium panels, using thin -0.016 inch sheets, meeting LFC surface smoothness requirements. Two large panels 28 x 28 inches were fabricated as final demonstration articles. The first was flat on the top and bottom sides demonstrating the capability of the tooling and the forming and diffusion bonding procedures to produce flat, defect free surfaces. The second panel was configurated for LFC porous panel treatment by forming channels with dimpled projections on the top side. The projections were machined away leaving holes extending into the panel. A perforated titanium sheet was adhesively bonded over this surface to complete the LFC demonstration panel. The final surface was considered flat enough to meet LFC requirements for a jet transport aircraft in cruising flight.