Characterization of Explosively Bonded and Fired Tantalum Liners Applied to 25-mm Gun Tubes

摘要

Characterization analyses were conducted on sections taken from three truncated 25-mm gun tubes that were explosively bonded with pure tantalum. Two of the barrels had been test fired and one was received in the pre-fired condition. The two test-fired tubes consist of one smoothbore design and one no- twist rifled bore design. The specimen received in the pre-fired condition was the smoothbore design. Characterization work included macroscopic examination, liner thickness measurements, microstructural analysis, microhardness testing, adhesion testing, scanning electron microscopy, energy dispersive spectroscopy, wavelength dispersive spectroscopy, hydrogen analysis, and pulsed laser heating. Characterization results indicate vast improvement over the erosion characteristics of standard nitrided 2S-mm Bushmaster gun tubes when firing the unfielded, original M919 propellant (100% HE 9053). Some areas of concern in the performance of the liner include heavy heat-check cracking, severe gas erosion, high concentration levels of hydrogen, and surface oxidation of the tantalum liners.