Helium is formed in metals as a secondary product of fission/fusion energy technology. Even though helium is chemically inert and essentially insoluble in metals, under specific exposure conditions it is known to cause them to lose their ductility. At high temperatures, helium atoms produced from the transmutation of 10B or from a two-step process with 58Ni in amounts as low as a few parts per million migrate to grain boundaries to cause inter-granular failure. Ion implantation of helium may cause a similar effect. More recently it has been found that helium produced from tritium decay at or slightly above room temperature also markedly degrades the mechanical properties of metals. In order to design alloys of the future it is necessary to understand the mechanisms responsible for this helium embrittlement.

Early experiments found that helium is strongly trapped at radiation-produced defects in metals. Atomistic calculations using pair potential interactions verified these findings. It was initially thought that the helium embrittlement in metals was due to the trapping and subsequent bubble formation at radiation-induced defects. It has been shown, however, that helium may be trapped in metals even in the absence of radiation damage. Thomas et al. found that 3He generated at low temperatures from tritium decay remained trapped in nickel upon heating to 500°C. In both this experimentand a subsequentone in gold the helium was introduced without the production of radiation damage. In this second experiment Thomas used transmission electron microscopy to see in the gold small (10Å) bubbles that had been implanted with low-energy (sub-damage threshold) helium.

The aluminum-air power cell is being developed as a power supply for general purpose electric vehicles because it can provide them with the range, acceleration performance, and rapid refueling capability of current internal combustion engine vehicles. This paper describes the general characteristics of the systems and the materials research effort sponsored by DOE to improve the characteristics of the air and aluminum electrodes.

The boundaries between the present performance of materials and the requirements of device designers have for centuries been moving forward. The steps taken to draw these two together are sometimes large; more often they are small. As they occur, we find materials that are stronger, have larger magnetic moments, have higher electron mobilities, etc. Each time the property profile improves, understanding of the physical and chemical properties advances, and new engineering devices based on the improved profile are invented and developed.

The purpose of the Center for Advanced Materials (CAM) at the Lawrence Berkeley Laboratory (LBL) is to enhance the inter-play between advances in the property profiles of materials and advances in the chemical and physical understanding of them. For this purpose, the location of CAM can be described as ideal. The proximity of this national laboratory to the campus of the University of California at Berkeley provides an unusually rich intellectual setting for the Center. It also provides unique opportunities for the University students and faculty who conduct materials-related research. Indeed, the arrangement should be a model for similar organizations, and it represents a solid method for strengthening materials science and technology throughout the nation.

National policy in critical materials has given the national laboratories—including LBL—strong direction and incentive to collaborate with industry and the research universities. This incentive led to the establishment of CAM in order to build on the symbiosis between LBL and the University of California at Berkeley. It strives to extend this symbiosis by bringing industry into the ongoing educational process and by making its special facilities more readily available to industrial researchers.