Mark Alexander Carroll

US Patent:

41211570, Oct 17, 1978

Filed:

Jul 5, 1977

Appl. No.:

5/812873

Inventors:

Henry J. Weltman - Fort Worth TX
Mark T. Carroll - Fort Worth TX
John E. Halkias - Fort Worth TX
William T. Kaarlela - Fort Worth TX
Jack D. Reynolds - Fort Worth TX

Assignee:

General Dynamics Corporation - Fort Worth TX

International Classification:

G01R 3312

US Classification:

324216

Abstract:

A method for forming and preserving a permanent record of inspections of workpieces or the like having drilled holes or other metallic surface conformations characterized by applying a castable, plural component, magnetically active material comprised of room temperature vulcanizing, or polymerizing, rubber containing magnetizable particles and specific sensitizing agents; magnetizing the area to be inspected, so as to cause migration of the particles in the rubber before the viscosity becomes too high for the magnetized particles to migrate to the situs of an imperfection, or flaw; forming a magnetic rubber inspection replica or record of the alignment of the magnetizable particles adjacent the interface between the casting and the workpiece by increasing the viscosity of the rubber above 4000 centipoises and to flexible elastic form so as to immobilize the particles; removing the magnetic rubber inspection record thus formed and inspecting for concentrations of the magnetizable particles to delineate flaws; and carrying out post-inspection procedures. Also disclosed are specific formulations and ingredients thereof, including delineation of components that cure the problems of the prior art.