Welding Plastics by the Neutron Capture Process

Specimens of polymethylmethacrylate were welded by the neutron capture process using the ¹⁰B isotope. In general, very weak bonds were obtained, of the order of a 20-psi bond strength for naturally enriched boron. Bond strength increased with thermal-neutron fluence to 10¹⁵ n/cm². At higher fluences the strengths decreased and the specimens became very brittle, presumably from radiation damage by the fast neutrons and gamma rays present in the radiation field of the reactor. Comparison of experiment with theory suggests that only a small fraction of the interface area is being welded.