The Fourth International Cryogenic Materials Conference (ICMC) was held in San Diego, California in conjunction with the Cryogenic Engineer- ing Conference (CEC) on August 10-l4, 1981. The synergism produced by conducting the two conferences together remains very strong. In the ap- pl1cation of cryogenic technology, materials continue to be a demanding challenge, and sometimes, an obstacle. The association of materials and cryogenic engineers increases their awareness of recent research in each other's fields and influences the course of future research. Many contributed to the success of the...