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Technical Paper

Ultra-Downsizing of ICEs Based on True Atkinson Cycle Implementations. Thermodynamic Analysis and Comparison on the Indicated Fuel Conversion Efficiency of Atkinson and Classical ICE Cycles

2024-04-09
2024-01-2096
Ultra-Downsizing (UD) was introduced as an even higher level of downsizing for Internal Combustion Engines ICEs, see [2] SAE 2015-01-1252. The introduction of Ultra Downsizing (UD) aims to enhance the power, efficiency, and sustainability of ICEs while maintaining the thermal and mechanical strain within acceptable limits. The following approaches are utilized: 1 True Atkinson Cycles are implemented utilizing an asymmetrical crank mechanism called Variable Compression and Stroke Ratios (VCSR). This mechanism allows for extended expansion stroke and continuous adjustment of the Volumetric Compression Ratio (VCR). 2 Unrestricted two or more stage high-pressure turbocharging and intensive intercooling: This setup enables more complete filling of the cylinder and reduces the compression work on the piston, resulting in higher specific power and efficiency. 3 The new Load Control (LC) approach is based to continuous VCR adjustment.
Technical Paper

Wear Behavior of Hard Ceramic Coatings by Aluminum Oxide– Aluminum Titanate on Magnesium Alloy

2024-02-23
2023-01-5109
Magnesium and its alloys are promising engineering materials with broad potential applications in the automotive, aerospace, and biomedical fields. These materials are prized for their lightweight properties, impressive specific strength, and biocompatibility. However, their practical use is often hindered by their low wear and corrosion resistance. Despite their excellent mechanical properties, the high strength-to-weight ratio of magnesium alloys necessitates surface protection for many applications. In this particular study, we employed the plasma spraying technique to enhance the low corrosion resistance of the AZ91D magnesium alloy. We conducted a wear analysis on nine coated samples, each with a thickness of 6mm, to assess their tribological performance. To evaluate the surface morphology and microstructure of the dual-phase treated samples, we employed scanning electron microscopy (SEM) and X-ray diffraction (XRD).
Technical Paper

Analyzing Mechanical Behaviour of Aluminium Alloy Composites Reinforced with Ceramics

2024-02-23
2023-01-5110
Aluminium composites are remarkably used in automotive, aerospace, and agricultural sectors because of their lightweight with definable mechanical properties. The stir casting route was followed to fabricate cylindrical samples with base aluminium alloy LM4, LM4/SiC, LM4/Al2O3, and LM4/SiC/Al2O3. The tensile strength, compressive strength, hardness, and micro-structural analysis were performed on samples and Finite element analysis (FEA) was adopted to predict the failure modes of composites. The composites experimental results were found to be in line with the FEA results, however, the LM4/SiC/Al2O3 revealed better results on the mechanical properties when compared with other composite configurations. The mechanical properties improvement like hardness 5%-11%, tensile strength 10.26%-20.67%, compressive strength 15.19% - 32.58% and 71.52 - 82.1% reduction in dimension have been achieved in LM4/SiC/Al2O3 composite comparing to base metal.
Technical Paper

An Experimental Study of Mechanical Behaviour of Aluminium Based Stir Casted Metal Matrix Composite

2024-02-23
2023-01-5104
The requirement for lightweight, high-performance materials with higher wear resistance, which is critical in industries such as aerospace, automotive, and consumer-related sectors, has fueled the development of particle reinforced metal matrix composites (PRMCs). These materials are an appealing alternative for a broad variety of scientific and technological applications due to their remarkable mechanical qualities and low cost. The primary goal of developing metal matrix composite materials is to combine the favorable properties of metals and ceramics. This study included several experimental experiments to explore the behavior of stir-cast composites made of aluminum grade 6063 with varying amounts of SiC, Al2O3, and TiO2 reinforcements.
Journal Article

Investigation on the Surface Structure and Tribological Characterization of 10 wt.% ZrO2-Reinforced Alumina Prepared by Flame Spray Coating

2024-02-20
Abstract In this study, we have investigated the microstructural characteristics, the mechanical properties, and the dry sliding wear behavior of a ceramic coating consisting of zirconia (ZrO2) and alumina (Al2O3) deposited by flame spraying. A series of wear tests were carried out under a variety of loads and at two different sliding speeds. The evaluation included an examination of the coating microstructure, microhardness, coefficient of friction (COF), and wear resistance of the flame-sprayed coating. The results showed that the coatings had a perfectly structured micro-architecture and were metallurgically bonded to the substrate. The Al2O3 coating exhibited a fine granular structure with pores and oxides. The microstructure of Al2O3-10 wt.% ZrO2, on the other hand, showed a blocky structure with a uniform distribution of ZrO2 inclusions in the composite coating.
Standard

Titanium Alloy Bars, Forgings, and Forging Stock, 6Al - 6V - 2Sn, Annealed

2023-11-10
CURRENT
AMS6936D
This specification covers a titanium alloy in the form of bars up through 4.000 inches (101.60 mm) in nominal diameter or least distance between parallel sides, inclusive, forgings of thickness up through 4.000 inches (101.60 mm), inclusive, with bars and forgings having a maximum cross-sectional area of 32 square inches (206.5 cm2), and stock for forging of any size (see 8.6).
Technical Paper

Snow Particle Characterization. Part A: Statistics of Microphysical Properties of Snow Crystal Populations from Recent Observations Performed during the ICE GENESIS Project

2023-06-15
2023-01-1492
Measurements in snow conditions performed in the past were rarely initiated and best suited for pure and extremely detailed quantification of microphysical properties of a series of microphysical parameters, needed for accretion modelling. Within the European ICE GENESIS project, a considerable effort of natural snow measurements has been made during winter 2020/21. Instrumental means, both in-situ and remote sensing were deployed on the ATR-42 aircraft, as well as on the ground (ground station at ‘Les Eplatures’ airport in the Swiss Jura Mountains with ATR-42 overflights). Snow clouds and precipitation in the atmospheric column were sampled with the aircraft, whereas ground based and airborne radar systems allowed extending the observations of snow properties beyond the flight level chosen for the in situ measurements.
Technical Paper

Comparability of Hot-Wire Estimates of Liquid Water Content in SLD Conditions

2023-06-15
2023-01-1423
Future compliance to FAA 14 CFR Part 25 and EASA CS-25 Appendix O conditions has required icing wind tunnels to expand their cloud simulation envelope, and demonstrate accurate calibration of liquid water content and droplet particle size distributions under these conditions. This has led to a renewed community interest in the accuracy of these calibrations, and the potential inter-facility bias due to the choice of instrumentation and processing methods. This article provides a comparison of the response of various hot-wire liquid water content instruments under Appendix C and supercooled large droplet conditions, after an independent similar analysis at other wind tunnel facilities. The instruments are being used, or are under consideration for use, by facilities collaborating in the ICE GENESIS program.
Journal Article

Research on Surface Treatment Coating on Titanium Alloy Based on Laser Cladding Technology

2023-03-07
2023-01-0980
This paper will illustrate the surface treatment coating that forms a strong metallurgical bond between the titanium alloy matrix regarding the high friction properties and challenging lubricating of titanium alloys. In this research, TC4 has been selected as a base material instead of TiC. Then Ni-composite coating was employed as the surface treatment of TC4 by laser cladding (LC) process. The Ni-based alloy coating material powder is good self-fluxing, has high-temperature resistance, and is analytically pure with 200 mesh. The chemical properties of Ni composite coating include 31.2 % Chromium, 8%Titenium, and 3.6% Carbon. Overall characterization and microstructure analysis of the prepared coating utilizing OM, XRD, SEM, EDS, and EPMA with different laser-specific energies (LSP) performance impact. It is evident that an excellent coating can be employed at the LSP of about 12.5kJ/cm2.
Magazine

Aerospace & Defense Technology: December 2022

2022-12-01
Why are Aerospace & Defense Companies Embracing Additive Manufacturing? Simplifying Power Design with Modular Architectures The Role of DevSecOps in Modern Edge Systems Making Machines Curious Designing Multi-Channel Microwave Radio Systems Using Optical Interconnects Solving Military Satellite, Radar and 5G Communications Challenges with GaN-on-SiC MMIC Power Amplifiers Advanced Airborne Defensive Laser for Incorporation on Strike Fighter Aircraft A technical and operational analysis of an airborne "hard-kill" Ytterbium fiber laser-based anti-missile system for use on strike fighters. Additive Manufacturing Utilizing a Novel In-Line Mixing System for Design of Functionally Graded Ceramic Composites Exploring the development of a direct ink writing system with multimaterial and in-line mixing capabilities for printing inks composed of high solids-loaded ceramic particulate suspensions.
Technical Paper

Cold Spray Repair Process Optimization Through Development of Particle Impact Velocity Prediction Methodology

2022-10-05
2022-28-0098
Cold spray (CS) is a rapidly developing solid-state repair and coating process, wherein metal deposition is produced without significant heating or melting of metal powder. Solid state bonding of powder particles is produced by impact of high-velocity powder particles on a substrate. In CS process, metal powder particles typically of Aluminum or Copper are suspended in light weight carrier gas medium. Here high pressure and high temperature carrier gas is expanded through a converging-diverging nozzle to generate supersonic gas velocity at nozzle exit. The CS process typically uses Helium as the carrier gas due to its low molecular weight, but Helium gas is quite expensive. This warrants a need to explore alternate carrier gases to make the CS repair process more economical. Researchers are exploring another viable option of using pure Nitrogen as a carrier gas due to its significant cost benefits over Helium.
Standard

Magnesium Alloy, Processes for Pretreatment and Prevention of Corrosion on

2022-09-14
CURRENT
AMSM3171A
This specification covers general requirements for the apparatus, material, and procedures to be used in the processing of magnesium base alloys for the purpose of increasing their corrosion resistance and by producing surfaces suitable for organic paint finish systems.
Book

Composite Materials Handbook Volume 1 - Revision H

2022-09-06
The first volume of this six-volume compendium contains guidelines for determining the properties of polymer matrix composite material systems and their constituents, as well as the properties of generic structural elements, including test planning, test matrices, sampling, conditioning, test procedure selection, data reporting, data reduction, statistical analysis, and other related topics. Special attention is given to the statistical treatment and analysis of data. Volume 1 contains guidelines for general development of material characterization data as well as specific requirements for publication of material data in CMH-17. The primary purpose of this volume of the handbook is to document industry best-practices for engineering methodologies related to testing, data reduction, and reporting of property data for current and emerging composite materials. It is used by engineers worldwide in designing and fabricating products made from composite materials.
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