Material microstructure is a significant determinant of the tensile stress at which materials fail Using a high-energy laser to drive shocks in thin slabs, we have explored the role material microstructure plays on the spall strength of high-purity and alloyed aluminum at strain rates of (2–75)×106s−1 Slabs of pure recrystallized Al and recrystallized or cold worked Al+3wt% Mg were shock driven using the Z-Beamlet Laser at Sandia National Laboratories Velocity interferometer measurements determined the spall strength of the materials, and postshot target analysis explored the microscopic fracture morphology We observed the greatest spall strength for large-grained, recrystallized high-purity aluminum, with the dominant failure mode being ductile and transgranular We observe for the first time at these strain rates fracture features for a fine-grained Al+3wt% Mg that were a combination of brittle intergranular and ductile transgranular fracture types Postshot analysis of target cross sections and hy

Laser-induced spallation of aluminum and Al alloys at strain rates above 2 × 106 s-1

The results are presented of mechanical tensile and shear tests of steels of different strength levels with plastic strain rates of 3·10−3–105 sec−1. The changes in the characteristics of strength, plasticity, and microstructure are analyzed in relation to the strength level of the steel and loading rate. For steels of different structural classes at high deformation rates (approximately up to 105 sec−1) a significant increase in the characteristics of strength and plasticity is observed.

Influence of loading rate on the mechanical properties of steels of different strength levels

Cone formation in targets beneath a penetrating projectile

An increase in the velocities of automobile and aerospace transport and, simultaneously, the necessary of decreasing their masses increase the requirements to the operating reliability of used materials and constructions. In this case, the operation of a material under dynamic impact loads remains in nonnormative ranges. This work presents a comprehensive technique of studying and predicting the behavior of materials under conditions of dynamic tension. A possibility of increasing the strength properties of materials by severe plastic deformation (SPD) in a wide range of varying parameters of external loads and the fi-xation of these changes in the framework of the proposed technique is demonstrated using Al–Mg and Al‒Cu–Mg aluminum alloys as examples.

Effect of Ultrafine-Grained Structure of a Material on the Strength Characteristics of an Aluminum Alloy upon Impact Loads

Deformation of metals at strain rates above 104 sec−1

1.

Within the limits of experimental error, the impact compressibility of different aluminum alloys in the test pressure range is weakly dependent on chemical composition, treatment process, and material strength.




2.

Resistance to deformation in the high strain rate region increases with increasing strain rate, and the boundary for a marked effect of strain rate on its resistance moves into the region of higher rates.




3.

In the case of the absence of a correlation between strength properties with uniaxial stress and uniaxial strain states, their sensitivity to loading rate may be connected with a single viscosity factor.

V. V. Astanin

Papers

Mechanical properties of a high-strength aluminum alloy with shock loading

Experimental determination of fracture stresses during cleavage in elastic-plastic materials

Determining the strength of joints in materials in impulse loading