Role of the Insulating Layer from Ti02-Wax Liner in Reducing Gun Tube Wear
Abstract
Adoption of wear-reducing liners into the 105 mm M392 APDS projectile increased the wear life of the M68 cannon from 100 to 400 rounds for polyurethane foam and 10,000 rounds for TiO2-wax. Heat transfer measurements on the M68 tank cannon concluded the additives reduced heat input and the efficiency of the TiO2-wax rested with the presence of flaps and an insulating deposit formed with successive firings of Ti02-wax rounds. To test the hypothesis the insulating residue contributes to design additives, a 1200-round firing test was conducted in which 600 APDS and 600 HEP rounds were fired alternatively. Based on wear per round established for APDS and HEP rounds, one would have expected 0.19mm of wear for the 1200 rounds. Instead, the 1200-round test produced 1.9 mm of wear establishing the importance of the insulating residue. It was also observed the secondary wear increased for the alternate APDS-HEP round test. This confirms an earlier hypothesis that the secondary wear arises because the additives is not effective down bore. The total wear of 1.9 mm was twice as much as predicted for a correlation between heat input and wear. It is postulated that the APDS round is more erosive when it is preceded by a low-velocity HEP round than by another APDS round. The extra erosivity of the APDS round is attributed to a thicker oxide layer left on the barrel by the HEP round.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1980
- Accession Number
- ADA085717
Entities
People
- J. Richard Ward
- Timothy L. Brosseau
Organizations
- Ballistic Research Laboratory