Technical report describing the investigation undertaken to determine the necessary requirements for obtaining sound bonded joints on tantalum. Corrosion and Mass Transfer Loops LTTN 237A and 427 called for fabrication of 430 stainless steel clad tantalum tubing. Since there was little or no experience at welding this material at CANEL, specimens were welded using vacuum chambers and plastic chambers as normally used for loop fabrication. Resistance welding was performed without the use of a special atmosphere producing sound bonds.

This technical report presents measurements of the thermal expansion of five titanium carbide type cermets from 68 to 1800F. These cermets are designated by Kennametal, Inc., as K 138A, K 150A, K 152B and K 162B. They contain from 64 to 80 weight percent titanium carbide, 10 to 30 weight percent metal binder and 6 to 10 weight percent other carbides. The metal binders are cobalt, nickel, and nickel and molybdenum. An attempt was made to calculate the thermal expansion of each type cermet from thermal expansions of the constituents. The expansion of the mixture was computed by weighting and expansions of the constituents according to (1) weight percent of the constituents, (2) volume percent of the constituents and (3) according to a value developed for mixtures by P. S. Turner. It was found that expansions computed according to volume percent and by Turner's method agreed with measured values with +- 5 percent. The values calculated by weight percent were from 5 to 11 percent higher than the observed values. The thermal expansions of these cermets are compared with the expansions of a group of metals and alloys.