Dynamic failure of steel under hypervelocity impact of polycarbonate up to 9 km/s

Abstract

Metallurgical analysis and computer simulation of a solid steel sphere under shock loading AIP Conf.We performed hypervelocity impact experiments on SS400 steel with a polycarbonate projectile at velocities up to 9 km/s. Spall fracture damages were observed near a rear surface of the impacted target. The microstructure and microdamages were examined using optical microscopy and scanning electron microscopy. The ␣Ϫ phase transition region was observed near the crater. Cracks parallel to the impact direction were observed below the crater, and radial cracks grew from the ␣Ϫ phase interface at high velocity impact tests, especially above 6 km/s. Cleavage was the dominant mechanism for a spall fracture surface, and ductile fracture structures were also observed at the edge of spall plane. Geometric spall behaviors were well reproduced by numerical simulations using a hydrocode. These simulation results also showed that the cracks below the crater would be due to dynamic tensile stresses. The calculated results using the value of 13 GPa as the transition pressure showed that the duration necessary for the phase transition is about 150 ns for impact velocity of 8.8 km/s.

Hypervelocity impacts as a source of deceiving surface signatures on iron-rich asteroids

“…All these microstructures and microdamages are indicative of dynamic failures. They are similar to other dynamic failures observed on steel under hypervelocity impacts ( 31 , 32 ).…”

Modeling Plastic Deformation of Steel Plates in Hypervelocity Impact Experiments

“…A study of hypervelocity impact damage on martensitic steel armor highlighted the importance of better understanding spall damage and pressure-induced phase transitions [4]. Dynamic failure of SS400 steel under polycarbonate projectile impact was studied with a velocity up to 9 km/s and spall, pressure-induced α↔ε phase transition were discussed along with hydrocode simulation [5].…”

New Method for Projectile Velocity Measurement Using Faraday-Type Electromagnetic Sensor for Hypervelocity Impact Experiments and Detection Efficiency of the Method

“…Light-gas guns have been widely used to study hypervelocity impact phenomena [1][2][3][4][5][6][7][8] and equations of state and various properties of materials under extremely high pressures. [9][10][11][12][13][14][15][16][17][18] Since projectile velocity is one of the most essential parameters in determining shock pressure, a highly accurate method is required for measuring projectile velocity.…”