Using impedance engineering to design better ceramic composites for armour

This project seeks to investigate the viability of an alternative penetrator-defeating mechanism based on the use of impedance engineering to manage stress wave reflections. Stress waves, especially tensile waves, are problematic for ceramics as ceramics are an order of magnitude weak in tension than in compression. Theoretical calculations and simulations using Spectrum were used to validate the hypothesis. Fabrication of such impedance engineered laminates were shown to be achievable via traditional hot-pressing and robocasting. Fully dense (>99% TD) SiC with solid-state sintering additives were produced using robocasting with a flexural strength of 469 MPa (3PBT) and Young’s Modulus of approximately 430 MPa (ultrasonic techniques). Robocasting of SiC-B4C composites across the entire range of compositions was shown to be possible and pressureless sintered to high densities (>97% TD). Robocasting of ceramics and ceramic matrix composites based on SiC-B4C forms the bulk of the experimental work and is critical in ensuring that they can be deployed in armour applications. Characterisation of the fabricated ceramics showed mechanical properties comparable to other SiC/B4C materials in literature. While success in the ultrasonic characterisation of the interfaces was limited, a deeper understanding of the proposed mechanism was achieved.Open Acces

Nanotribological and Nanomechanical Investigation of Nanomaterials

This dissertation primarily documents the quantification of the interfacial behavior of carbon based nanomaterials, which includes two categories, one is the nanofriction properties evaluation of aligned carbon nanotube carpets, few-layer graphene as well as three types of functionalized graphene nanoribbons, the second is the mechanical characterization of individual functionalized carbon nanofibers and the interfacial fracture toughness quantification in carbon nanotube/polymer derived ceramics nanocomposite. The aligned carbon nanotube carpets have a highly anisotropic friction behavior, which means the friction force are lower for transversely aligned CNTs side than for vertically aligned CNTs surface. We can also tune the friction properties of graphene ribbons by grafting different functional groups. In addition, two narrow angular regions with high friction, separated by a wide angular interval with low friction, were identified between graphene and highly oriented pyrolytic graphite. The distance between the two friction peaks is 61◦, which corresponds well with the 60◦ symmetry of individual atomic layers in the graphite lattice. The technique that involves the usage of mcirodevices and nanoidenter was used to conduct tensile tests on pristine, fluorinated and amino-functionalized carbon nanofibers, which were found to exhibit varied load-bearing abilities and unique fracture modes. The technique was also used to perform single fiber pullout experiments to study carbon nanotube/polymer derived ceramic interface

Nanostructured advanced ceramics for armour applications

Ceramics have been widely used for personnel and vehicle armour because of their desirable properties such as high hardness and low density. However the brittle nature associated with the ceramic materials, i.e. low toughness, reduces their ability to withstand multiple ballistic hits. The present work is focused on ceramic armour materials made from alumina and zirconia toughened alumina (ZTA). The effects of grain size and zirconia phase transformation toughening on the mechanical and high strain rate properties in both materials were investigated in detail. Alumina, 10%, 15% and 20% nano ZTA with 1.5 mol% yttria stabiliser were produced with various grain sizes. The processing of the materials started from suspension preparation, spray freeze drying of the suspension and die pressing to produce homogeneous green bodies with densities above 54%. Then, the green bodies were sintered using conventional single stage and/or two-stage sintering to produce the samples with full density and a range of grain sizes (0.5 to 1.5 μm alumina grains and 60 to 300 nm zirconia grains). The effects of the processing conditions on the microstructures were studied and the optimum processing route for each sample was determined. [Continues.

Spinoff 2010

Topics covered include: Burnishing Techniques Strengthen Hip Implants; Signal Processing Methods Monitor Cranial Pressure; Ultraviolet-Blocking Lenses Protect, Enhance Vision; Hyperspectral Systems Increase Imaging Capabilities; Programs Model the Future of Air Traffic Management; Tail Rotor Airfoils Stabilize Helicopters, Reduce Noise; Personal Aircraft Point to the Future of Transportation; Ducted Fan Designs Lead to Potential New Vehicles; Winglets Save Billions of Dollars in Fuel Costs; Sensor Systems Collect Critical Aerodynamics Data; Coatings Extend Life of Engines and Infrastructure; Radiometers Optimize Local Weather Prediction; Energy-Efficient Systems Eliminate Icing Danger for UAVs; Rocket-Powered Parachutes Rescue Entire Planes; Technologies Advance UAVs for Science, Military; Inflatable Antennas Support Emergency Communication; Smart Sensors Assess Structural Health; Hand-Held Devices Detect Explosives and Chemical Agents; Terahertz Tools Advance Imaging for Security, Industry; LED Systems Target Plant Growth; Aerogels Insulate Against Extreme Temperatures; Image Sensors Enhance Camera Technologies; Lightweight Material Patches Allow for Quick Repairs; Nanomaterials Transform Hairstyling Tools; Do-It-Yourself Additives Recharge Auto Air Conditioning; Systems Analyze Water Quality in Real Time; Compact Radiometers Expand Climate Knowledge; Energy Servers Deliver Clean, Affordable Power; Solutions Remediate Contaminated Groundwater; Bacteria Provide Cleanup of Oil Spills, Wastewater; Reflective Coatings Protect People and Animals; Innovative Techniques Simplify Vibration Analysis; Modeling Tools Predict Flow in Fluid Dynamics; Verification Tools Secure Online Shopping, Banking; Toolsets Maintain Health of Complex Systems; Framework Resources Multiply Computing Power; Tools Automate Spacecraft Testing, Operation; GPS Software Packages Deliver Positioning Solutions; Solid-State Recorders Enhance Scientific Data Collection; Computer Models Simulate Fine Particle Dispersion; Composite Sandwich Technologies Lighten Components; Cameras Reveal Elements in the Short Wave Infrared; Deformable Mirrors Correct Optical Distortions; Stitching Techniques Advance Optics Manufacturing; Compact, Robust Chips Integrate Optical Functions; Fuel Cell Stations Automate Processes, Catalyst Testing; Onboard Systems Record Unique Videos of Space Missions; Space Research Results Purify Semiconductor Materials; and Toolkits Control Motion of Complex Robotics

INTER-ENG 2020

These proceedings contain research papers that were accepted for presentation at the 14th International Conference Inter-Eng 2020 ,Interdisciplinarity in Engineering, which was held on 8–9 October 2020, in Târgu Mureș, Romania. It is a leading international professional and scientific forum for engineers and scientists to present research works, contributions, and recent developments, as well as current practices in engineering, which is falling into a tradition of important scientific events occurring at Faculty of Engineering and Information Technology in the George Emil Palade University of Medicine, Pharmacy Science, and Technology of Târgu Mures, Romania. The Inter-Eng conference started from the observation that in the 21st century, the era of high technology, without new approaches in research, we cannot speak of a harmonious society. The theme of the conference, proposing a new approach related to Industry 4.0, was the development of a new generation of smart factories based on the manufacturing and assembly process digitalization, related to advanced manufacturing technology, lean manufacturing, sustainable manufacturing, additive manufacturing, and manufacturing tools and equipment. The conference slogan was “Europe’s future is digital: a broad vision of the Industry 4.0 concept beyond direct manufacturing in the company”