Friction and wear between rotating band and gun barrel during engraving process

• A novel gas-gun based test rig was specially designed to perform dynamic engraving tests.
• Engraving force of copper or Al–bronze rotating bands is an order of magnitude higher than that of the nylon rotating band.
• Severe friction and large plastic deformation have occurred during engraving process.
• Deformation behavior of rotating bands differs under different loading rates.

It is of great importance to investigate the occurrence of engraving (also known as “scoring”) of rotating bands during firing to achieve optimal design, manufacturing, use and maintenance of medium and large caliber rifled guns and their corresponding projectiles. In our present study, two short rifled gun barrel sections and projectiles with copper, Al–bronze and nylon rotating bands were prepared. Quasi-static and dynamic push tests were performed on the CSS-88500 Electronic Universal Testing Machine (EUTM) and a specially designed gas gun-based dynamic impact test rig. The quasi-static experimental results showed that the extruded materials accumulates at the end of the band and has not departed from the band base. However, the dynamic experimental results showed no clear accumulation, which is close to the recovered rotating band after firing. Large deformation and severe friction between rotating band and gun bore has occurred during engraving process. It is suggested that strain rate and temperature have great effects on the deformation behavior of rotating band during engraving process.