High Strain & Ballistic Materials

High Strain Rate and Ballistic Materials is focused on novel and specialized materials to enhance the performance and efficiency of Army weapons and protection systems, including lightweight extreme performance materials, novel energetic materials, and energy-absorbing materials.

Alloys

Aperiodic to Nanostructured Materials

Research based on experimental, computational, and analytic solutions relates to the design and thermal stabilization of metastable materials; specific focus is on the effective utilization and exploitation of nanostructured materials via the discovery of new compositions and/or defect and interface engineering, such as novel multiphasic solvent-solute combinations, augmented with grain size reduction and grain boundary modification techniques. Approaches entail the use of thermodynamic and kinetic principles to develop materials with unprecedented or greatly improved mechanical, thermal, or chemical properties.

Principal Investigator:

Dr. Kristopher Darling kristopher.darling.civ@mail.mil 410-306-0862

Deformation Processing of Lightweight Materials

Severe plastic deformation processing of novel materials entails the top-down refinement of coarse-grained microstructures to the ultra-fine and nanoscale regime, resulting in a dramatic improvement in strength without a loss of ductility. Methodologies include equal channel angular extrusion, high-pressure torsion, accumulative roll bonding, friction stir welding, and surface mechanical attrition treatment processing to create material systems with controlled properties such as texture, morphology, and unique or metastable phase chemistries.

Principal Investigator:

Dr. Kevin Doherty kevin.j.doherty18.civ@mail.mil 410-306-0871

Ceramics

Projectile/Target Interaction: High-Velocity Impact on Ceramics

Ceramics possess lower densities and higher hardness values compared to traditional metallic armor materials.  While our knowledge of the effects of material characteristics and processing is fairly well understood for these metallic materials, the same cannot be said of our knowledge for ceramics.  This work is focused on identifying and understanding the phenomena that govern the ballistic response of ceramics, and the effect of material chemistry and microstructure on these phenomena.  As an example, the ballistic response of boron carbide (B4C) is not well understood despite it being used in personnel protection technologies. Through state-of-the-art characterization methods and non-ballistic experiments, an improved understanding of the governing fundamental mechanisms and the effect of chemistry and structure will be achieved.  Findings will support the development of multi-scale models needed for Material-by-Design by identifying the dependences between material characteristics and inelastic deformation mechanisms, such as dislocations, twinning, stacking faults, stress-induced amorphization, melting, phase transitions, fracture, fragmentation, and granular flow.

Opportunities for collaboration are numerous.  Examples of areas of collaboration include dynamic crack propagation, granular flow of comminuted ceramics, in-situ diagnostics in ballistics and mechanical testing, chemical interactions at high heating rates, high-resolution electron microscopy to determine defect structure, atom-probe computed tomography, and molecular dynamics modeling. 

Principal Investigators:

Dr. Jerry LaSalvia jerry.c.lasalvia.civ@mail.mil 410-306-0745

Advanced Materials and Processing for Dismounted Soldier Protection

Basic and applied research and development for the improvement of Soldier protection performance (enhancement of penetration and back face-deformation resistance) with a key focus toward reduction of the Warfighter burden and improved effectiveness. Areas of effort in materials research for Soldier systems include: synthesis and processing of super-hard ceramic formulations (borides, carbides, oxides); innovative processing techniques to enable structural heterogeneity in ceramic materials (additive manufacturing – powder bed, binder jetting, ceramic stereolithography, polymer-derived ceramics); characterization and processing science for high-performance 1-D and 2-D composite fibers, membranes, and tapes; materials and design for reduction of behind-armor blunt trauma (BABT) in impact, ballistic, and blast events; enabling technologies and designs for increased armor flexibility and thermal management; and development of load-sharing/shunting/offsetting concepts.

Principal Investigator:

Dr. Lionel Vargas-Gonzalez lionel.r.vargas-gonzalez.civ@mail.mil 410-306-0702

Supporting Facility:
Materials and Manufacturing Science Division (MMSD) Laboratories (APG)
These include laboratories for processing science and small-scale manufacturing of ceramics, composites, and hybridized materials with both conventional and novel tooling (additive manufacturing facilities); mechanical and analytical characterization laboratories; ballistic ranges for high-rate characterization of protection system demonstrators and concepts.

Equipment Available:
Ceramics powder processing and high-temperature densification equipment, high-tonnage uniaxial presses, autoclaves, automated material assembly systems, tensile load frames, drop towers, SEM/TEM, confocal microscopy, micro-CT capabilities, high-rate cameras, flash X-ray, digital image correlation (DIC) materials characterization under multi-axial stress states at various loading rates.

Synthesis and Processing of Transparent Ceramic Nanocomposites

Mid-IR transparent materials have several areas of importance to the Army, specifically for applications such as windows for sensors, laser host materials and domes.  Generally, mid-IR transparent materials have low fracture toughness and hardness with makes them susceptible to damage during use. Recently there has been interest in dual phase transparent ceramics for these applications, which could potentially improve the fracture toughness and make these materials more suitable for their end use. This research opportunity seeks to reduce the grain size of dual phase transparent ceramics (nanocomposite) such that the grains are smaller than the wavelengths of interest. The purpose of this effort is to advance synthesis and processing for these unique transparent materials to enable expanded functionality by exploiting the best attributes of each of the two insoluble materials. Current ARL efforts are focused primarily on synthesis of the constituent nanocomposite materials, with the intent of focusing on processing research in FY18. ARL has significant capabilities for conventional and field-enhanced processing of transparent ceramics, including hot isostatic pressing (2000°C, 30ksi), hot pressing (2000°C, 6100psi), vacuum sintering, electric field-assisted sintering, magnetic field-assisted sintering, single-mode microwave sintering, and a variety of atmospheric sintering capabilities. This work would also derive significant benefit from integration of modeling to determine potential material systems, process development, and microstructural evolution of multiple phases.

Principal Investigator:

Dr. Victoria L. Blair, Victoria.L.Blair3.civ@mail.mil, 410-306-4947