Author: Delbert H. Fisher

Publisher:

Published: 1961

Total Pages: 82

ISBN-13:

A system has been developed for determining the conventional mechanical properties of materials at temperatures up to 4000 F in vacuum. Techniques for obtaining stress-strain properties in tension and compression are described in this report. Strains are measured optically directly at the gate section to an accuracy of plus or minus 50 microinches per inch in a 2-inch gage section. An evaluation of the system was made using a Mo-0.5Ti bar material. Exploratory work was conducted on graphite and a refractory sheet metal. The results for these tests are included in the report. With the objective of developing a temperature source for use above 4000 F, experiments were conducted to produce and to evaluate tantalum carbide-coated graphite heaters. Good coatings of tantalum carbide were produced both on thin-wall cylindrical heaters and on spiral heaters. It was found that carbon contamination of the atmosphere occurred such that tungsten shields of tungsten specimens were attacked at temperatures under 5400 F. Possible means of improving carbide coatings are suggested.