Patent Number: 047633999
Section: description

DETAILED DESCRIPTION OF THE DRAWINGS In FIG. 1 a fibrous composite laminate sheet 10 is shown in cross-section having a drilled hole 12 therethrough. A flame or plasma metal spray applicator 14 having an opening 16 therein is placed inside the hole 12 for introducing a metal spray indicated by arrows 18 to the edges of sides 20 of the bolt hole 12. Also shown in this drawing is the sheet 10 having preloads around hole pheriphery indicated by arrows 22. By preloading the sheet 10 prior to drilling the hole 12 the delamination and voids around the sides 20 of the hole 12 is greatly reduced. A metal plating 24 of the bolt hole 12 can be accomplished by a number of methods such as flame spraying, soldering, electro-plating and similar types of applications. The liquid metal 18 wicks into delamination and voids naturally occuring along the edges of the sides 20 of hole 12. The metal plating 24 or reinforcement may be in a thickness in the range of 0.002 to 0.02 inches for providing a substantial increase in the "through-the-laminate" strength. In FIG. 2 an alternate embodiment of the method of the invention is shown using a heated mandrel 30 inserted in the hole 12 of the composite laminate sheet 10. The sheet 10 is also under a preload indicated by arrows 22. In this embodiment a metal liner 32 is introduced with a B-stage adhesive 34 introduced between the liner 32 and the sides 20 of the hole 12. The heated mandrel 30 heats and expands the metal liner 32 and through conduction, the adhesive 34 is heated and adheres to the sides 34 of the hole 12 for providing a bonded metal liner therein. Changes may be made in the construction and arrangement of the parts or elements of the embodiments as described herein without departing from the spirit or scope of the invention defined in the following claims.