CoA. Notes: Materials (1963-1969)
Permanent URI for this collection
Browse
Browsing CoA. Notes: Materials (1963-1969) by Author "College of Aeronautics, (Cranfield)"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item Open Access Characteristics of the high temperature mechanisms of creep and recovery in graphite: part 1(College of Aeronautics, 1963-08) College of Aeronautics, (Cranfield)An apparatus has been developed for determining the high temperature creep and recovery characteristics of graphite by applying torsional stresses to thin-walled tubes. This method has the advantages of a simple stress system, constant stress for constant load, easy rapid removal of load and the independence of the strain measurement from thermal expansion. Torsional, stress-strain curves show a decreasing modulus with increasing temperature from 2000 - 2850°C. The rate of creep in this range is increased by increasing temperature and stress. Recovery rate is not so sensitive to increasing temperature. Using a method developed for metals, where recovery can be subtracted from forward creep, a secondary creep rate is deduced. This rate, when plotted according to the Arrhenius' equation, yields an activation energy for secondary creep of 154 kcals over the temperature range 2100 - 2700°C. These results are critically examined and the future extension of the work discussed.Item Open Access Characteristics of the high temperature mechanisms of creep and recovery in graphite: part 2(College of Aeronautics, 1964-02) College of Aeronautics, (Cranfield),The research reported in this document has been made possible through the support and sponsorship of the U.S. Department of the Army throlleh its European Research Office. This report, not necessarily in final form, is intended only for the internal management use of the Contractor and the U.S. Department of the Army.