Cg. Lee et S. Lee, CORRELATION OF DYNAMIC TORSIONAL PROPERTIES WITH ADIABATIC SHEAR BANDING BEHAVIOR IN BALLISTICALLY IMPACTED ALUMINUM-LITHIUM ALLOYS, Metallurgical and materials transactions. A, Physical metallurgy andmaterials science, 29(1), 1998, pp. 227-235
The present study is concerned with a correlation between dynamic defo
rmation properties obtained from the dynamic Kolsky bar test with the
adiabatic shear banding behavior developed in Al-Li alloys upon ballis
tic impact, and then with the ballistic performance. The selected mate
rials were a 2090 Al-Li alloy, a WELDALITE 049 alloy, and a 7039 Al al
loy, to allow a comparative study of different strengths and microstru
ctures. After the ballistic impact testing, the amount and the distrib
ution of adiabatic shear bands were examined using optical and scannin
g electron microscopes. In the front side of the impacted area, many t
hin delaminated sheets and a large amount of fragmentation were observ
ed in the 2090 alloy and the WELDALITE alloy, respectively. Near the i
mpacted region, a large amount of plastic flow also existed, and adiab
atic shear bands were hardly observed in the 2090 and the WELDALITE al
loys, whereas they easily formed in the 7039 alloy. Since adiabatic sh
ear bands usually deteriorate the impact resistance of target material
s, the ballistic performance of each alloy was discussed by comparing
the adiabatic shear banding behavior with microstructure, strength lev
el, and dynamic torsional properties.