Characterization of Some Material Properties of the Ablative Nose Cap of the M797 Training Round.
Abstract
An ablative nose cap, being developed for the M797 tank training round, has failed to destabilize consistently during flight over a temperature range of -50 deg F to 125 deg F. In this study, the zinc alloy AG40A, comprising the cap, was characterized with respect to mechanical and thermophysical properties. The die-casting production method must be improved in order to obtain standardized nose caps. This standardization will limit the variables controlling destabilization, but of itself, will not correct the flight inconsistencies. The degradation of mechanical strength of the zinc alloy is rapid, with minor increases in temperature; therefore, the lack of success in achieving destabilization is not directly a function of the material selected. The process of ablation, however, impedes the overall heating of the nose cap, and therefore delays the degradation of mechanical properties. The times available at elevated temperatures may be insufficient to achieve the desired property decay over the full range of service temperatures. The ablative process should be limited, if not entirely avoided, in order to achieve sustained elevated temperatures. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1983
- Accession Number
- ADA132089
Entities
People
- Judith Jenkins Kohatsu
Organizations
- United States Army Research Laboratory