CHARACTERIZATION OF 6061 T651 ALUMINUM PLATES SUBJECTED TO HIGH-VELOCITY IMPACT LOADS

Ballistic response of single or multi-layered metal armor systems subjected to kinetic energy pro-jectiles was investigated in many experimental, theoretical and numerical studies.In this study, 6061 T651 aluminum plates impacted by 9 mm bullets were investigated. Microstructural investigations have been carried out using optical microscopy. Microhardness values were used to determine the strength behavior of the plates. Influence of the plate thickness and impact velocity on the microstructure has been evaluated. It was concluded from the study that thinner plates are more prone to deformation hardening with high penetration depth values even at low impact velocities while thick plates are more susceptible to thermal softening with less penetration depths. Maximum hardness values were obtained just below the impact zone in both plate thicknesses

Structural Health Monitoring Application of Aviation Composite Materials Using Microscopic Techniques

Structural Health Monitoring (SHM) is a process that involves the observation and analysis of a system over time using periodically sampled response measurements to monitor changes to the material and geometric properties of engineering structures such as bridges, buildings, and aerospace composite structures. The goal of SHM is to detect changes in the structural behavior or condition that may indicate damage or degradation before a catastrophic failure occurs. SHM involves the implementation of damage detection strategies for structures of high importance. It is commonly used in civil engineering, aerospace engineering, and mechanical engineering applications to ensure the safety and reliability of structures. It improves the safety of aerospace composite structures by detecting damage at an early stage, preventing damage from occurring, improving reliability, and extending the life of the structure. SHM applications enable aircraft to spend less time on the ground and carry more passengers and cargo, thereby reducing operational costs. It can be utilized in various fields such as monitoring the health condition of aircraft tail and wing areas in the aviation industry, preventing damage and deterioration of car parts and components under operating conditions in the automotive sector, monitoring the health condition of bridges and tunnels in the transportation sector, and monitoring the health condition of wind turbines and other structures in the energy sector. Aerospace composite structures can suffer from several complex nonlinear damage modes, including impact damage, delamination, matrix cracking, fiber breakage, and voids. This study provides general and useful information on how structural health applications of aviation composites can be supported by microscopic techniques. In order to better understand the subject, an example aircraft composite structural component containing impact damage, which was mentioned above, was examined using microscopic techniques. In this investigation conducted using Stereo and Scanning Electron Microscopes (SEM), the identification of potential damage sources and the assessment of damage severity are explained in detail

Inspection of Surface Damage in Composite Materials with Different Techniques

Due to their excellent physical properties and high strength and stiffness relative to density, aerospace industry research is producing high-performance structural materials, such as composites, which are used in many critical structural parts like airframes, wings, rotor blades, propellers, and other components. However, during flight, these materials may be damaged by impact, thermal stress, moisture, and ultraviolet radiation. One of the most prevalent issues with composite materials is their challenging nature in terms of flaw detection during both manufacturing and use. When they are employed in the crucial areas that were previously indicated, this becomes a very serious issue. When evaluating the structural integrity of composites and looking for any damage, microscopes are a very useful instrument. Effective methods for identifying and analyzing damage include microscopic procedures like optical microscopy, stereomicroscopy, scanning electron microscopy (SEM), scanning ion microscopy (SIM), and atomic force microscopy (AFM). A variety of methods may be employed with microscopes to examine and identify deterioration in composite materials. It is often possible to examine overt deterioration on the surface of composite materials under the microscope utilizing a number of different approaches and procedures. Determining the kind, extent, distribution, and impact of the damage requires these inspections. Often employed techniques consist of: SEM is a method for high-resolution imaging of surface damage. It entails shining an electron beam onto the sample's surface and capturing pictures. SEM is a useful tool for identifying erosion, delamination, and microcracks. It is also possible to measure things like the damage's breadth and depth. Optical microscopes have a large field of view and look at damaged regions. This makes it possible to find tiny fractures or cracks that are invisible to the unaided eye. Furthermore, details on the degree of harm, the roughness of the surface, and the breadth and depth of the fractures may be acquired. To see damaged objects, optical microscopy is utilized. Cracks and damage locations are visible with optical microscopy. Optical microscopes can identify different kinds of damage by looking at the surface of the material. Damage like delamination, fiber breakage, cracks, and deformations are a few examples of these. This study examines the efficacy of microscopic methods and non-destructive testing in assessing the different kinds of damage that can occur at the interfaces between holes in composite materials. Composite test materials were chosen from glass fiber reinforced phenolic matrix composites that were produced in compliance with aerospace standards. The measurements led to the conclusion that using microscopic techniques has benefits like speed and field suitability. However, the continuous development and improvement of new methods in this field will contribute to a better understanding of layered composite materials and the development of safer and more durable structures

Development of a Low-Cost Wire Arc Additive Manufacturing System

Due to their unique advantages over traditional manufacturing processes, metal additive manufacturing (AM) technologies have received a great deal of attention over the last few years. Using current powder-bed fusion AM technologies, metal components are very expensive to manufacture, and machines are complex to build and maintain. Wire arc additive manufacturing (WAAM) is a new method of producing metallic components with high efficiency at an affordable cost, which combines welding and 3D printing. In this work, gas tungsten arc welding (GTAW) is incorporated into a gantry system to create a new metal additive manufacturing platform. Design and build of a simple, affordable, and effective WAAM system is explained and the most frequently seen problems are discussed with their suggested solutions. Effect of process parameters on the quality of two additively manufactured alloys including plain carbon steel and Inconel 718 were studied. System design and troubleshooting for the wire arc AM system is presented and discussed

Evaluation Of Foreign Object Damage On The Fan Blades with Microscopic Techniques

Foreign object damage (FOD) is a common problem in gas turbine engines, particularly in the fan and compressor blades. FOD generally occurs when hard body particles are ingested into an aero-engine fan and compressor blade. High-speed impact on fan titanium alloy blades leads to foreign object damage, which weakens the fatigue performance of the blades. It is important to note that FOD can also cause damage that is not visible to the naked eye, such as internal cracks or fatigue damage. Therefore, regular inspections and maintenance are crucial to detect and prevent FOD damage in gas turbine engines. Also using a microscope for the inspection of blades is important. Proper examination of blades damaged by foreign or domestic object can shed light on blade status and prevent further damage in the future. Here are some of the benefits of using a microscope for blade inspection: Microscopes can provide high magnification and resolution, allowing for detailed inspection of the blade surface and any defects or damage. Microscopes can help detect and identify small cracks, chips, or other forms of damage that may not be visible to the naked eye. Microscopes can provide accurate measurements of the blade's dimensions, which can be important for quality control and maintenance purposes. Microscopes can help identify the root cause of any damage or wear on the blade, which can inform future design and manufacturing decisions. Microscopes can provide visual documentation of the blade's condition, which can be useful for tracking changes over time and for communicating with other stakeholders. Overall, using a microscope for blade inspection can help ensure the safety, reliability, and performance of gas turbine engines and other equipment that relies on blades. In this study, a comparison was made between visual inspection, borescope control, stereo microscope and SEM-EDX microscope methods used in the detection and removal of foreign material damage. The advantages and disadvantages of these 4 methods are comparatively examined and presented to the attention of the reader

Electron beam welding varestraint test of ALLVAC 718 Plus™ for aviation technology

The improvements of materials used in aircraft gas turbine engines which constitute 50% of total aircraft weight must protect its actuality continuously. Utilization of super alloys in aerospace and defense industries can not be ignored because of excellent corrosion and oxidation resistance, high strength and long creep life at elevated temperatures. The newly innovated ALLVAC 718 Plus superalloy which is the last version of Inconel 718 has been proceeding in the way to become a material that aerospace and defense industries never replace of any other material with combining its good mechanical properties, easy machinability and low cost. In spite of their superior properties, these materials suffer from wear, tear and crack in order to be exposed to the elevated working temperatures in service. Therefore EBW varestraint test is designed to investigate the hot cracking susceptibility of Electron beam welded ALLVAC 718 plus