The possibility of nondestructively characterizing the microstruc­ ture, morphology or mechanical properties of materials is certainly a fascinating subject. In principle, such techniques can be used at all stages of a material's life - from the early stages of processing, to the end of a structural component's useful life. Interest in the subject thus arises not only from a purely scientific point of view but is also strongly motivated by economic pressures to improve productivity and quality in manufacturing, to insure the reliability and extend the life of existing structures. The present volume represents the edited papers presented at the Second International Symposium on the Nondestructive Characterization of Materials, held in Montreal, Canada, July 21-23, 1986. The Proceedings are divided into eight sections, which reflect the multidisciplinary nature of characterizing materials nondestructively: Polymers and Composites, Ceramics and Powder Metallurgy, Metals, Layered Structures/Adhesive Bonds/Welding, Degradation/Aging, Texture/ Anisotropy, Stress, and New Techniques. Invited papers by R. Hadcock of Grumman Aircraft Systems, R. Cannon of Rutgers University, H. Yada of Nippon Steel and R. Bridenbaugh of Alcoa review respectively the processing of polymer matrix composites, ceramics, steel and aluminum, emphasizing the need for material property sensors to improve process and quality control. Two other invited papers, one by A. Wedgwood of Harwell and the other by P. Holler of the IzFP in Saarbrucken review state of the art techniques to characterize particulate matter and metals respectively.