The suitability of Tophet C-Alloy 52/Kovar weldments to hydrogen embrittlement were investigated because of their potential as candidate materials in fabrication of minaturized initiators for pyrotechnics. Cathodic charged samples were statically loaded for extended periods of time resulting in no load failures and in ductile fracture surfaces indicating resistance to hydrogen embrittlement. 20 figures.

The web growth investigation portion of this program was spent in growing a backlog of primitive dendrites and developing a number of dendritic seed crystals having a variety of twin plane spacings. These seeds are to be used in the determination of the optimum twin spacing for dendritic-web growth. Having determined the optimum twin spacing for the seed dendrites, the optimized seeds will be used in the experimental part of the investigation to determine the limitation on the growth width and pull rate of the dendritic-web section. Primitive dendrities containing 2,3,4, and 5 twin planes with twin plane spacings of 0.6 to 19.2 mm. have been grown. A supply of dendrite seed crystals have been grown from these primitive dendrites. Computer programs have been developed that appear adequate for the thermal analysis of the dendritic-web growth. A preliminary two dimensional thermal model of the melt, crucible, susceptor and lid has been completed and numerical results obtained. In this model only radiation heat transfer was assumed for the lid. The temperature profiles obtained were thus lower than is found experimentally in the furnace. The characterization experiments have all been tested and found adequate for characterization of the material grown in the …

The thickness of alumina armor plate is determined which will stop a 10-g steel projectile traveling at 2.1 and 3.0 mm/s.