Browse Topic: Ceramics

Items (406)

Physical Durability of Advanced Ceramic Substrates for Ultra Low Emissions Applications

2022-01-065903/29/2022

In the face of tightening GHG regulations, vehicle ICE powertrains must now adopt new methods to achieve superior fuel economy and further reduce tailpipe gaseous emissions. Some recent strategies by OEMs for meeting these objectives include the downsizing of their engine displacement, the adoption of aggressive turbocharging, and the close-coupled locating of the exhaust aftertreatment. Ceramic substrates, the principal enabling technology within established aftertreatment systems, must further demonstrate enhanced performance qualities to survive and continue to perform in this more severe operating environment. This paper will summarize performance studies conducted on advanced ceramic substrates of high porosity and thin wall monolith cordierite design. The testing results correspond with OEM technical expectations and include the following: thermal shock resistance studies from engine exhaust heat up events, mechanical strength evaluation from harsh vibration exposure, and

Craig, Angus, Warkins, Jason, Bhargava, Rajesh

Effect of Material Anisotropy on Thermal-Mechanical Instabilities in Metal-Free Friction Materials

2021-01-128910/11/2021

An anisotropic ceramic matrix composite (CMC), which consists of a silicon carbide (SiC) based ceramic matrix reinforced with carbon (C) fibers, is considered as a metal-free friction material replacement in brake and clutch applications. The fibers are assumed to have a circular cross-section, arranged unidirectionally and packed in a rectangular array without the presence of voids. The rule of mixture showed the C-SiC composite to be transversely isotropic with the circumferential plane as the plane of isotropy. A set of parametric studies have been performed to computationally investigate the dominant parameters that affect thermal-mechanical instabilities. It is found that the chance of thermal buckling in the friction disc can be minimized by reducing the elastic moduli in the radial and circumferential directions, or by reducing the coefficient of thermal expansion in the same directions. Meanwhile, the material properties in the axial direction do not have a significant effect

Shaahu, Joseph-shaahu, Koranteng, Kingsford, Yi, Yun-Bo

Decoding Genuine Ceramic Pad Formulations- Materials and Processing

2021-01-127710/11/2021

The need to develop genuine ceramic composites for PV applications arose to overcome the challenges associated with traditional semi-metallic pads. The main focus is to achieve better performance, low noise, better pad and rotor wear, and low dust compared to semi- metallic pads. In general, brake pads convert kinetic energy to thermal energy through friction, and operating temperature in semi-metallic brake pads is higher due to the presence of steel having high thermal conductivity. Over the last decade, the customer preference has moved over to ceramic pads due to light coloured pad surface, low rotor and pad wear and low dust compared to semi-metallic pads. The traditional steel has been replaced by Aramid, engineered ceramic fibre, potassium titanate (TISMO D), lapinus fibre (RB 250) to impart similar/better performance. The current work investigates the characterisation of genuine ceramic and semi-metallic composites. Three genuine ceramic and one semi-met composite have been

Tomar, Bharat, Ali, Sharafat, Ellis, Keith, Choudhary, Yogesh

Recommended Practice for Determining Material Properties of Li-Battery Cathode Active Materials

J3021_202105-TEST-REC (Historical)05/28/2021

This SAE Recommended Practice provides a set of test methods and practices for the characterization of lithium ion battery cathode active material. It is beyond the scope of this document to establish criteria for the test results, as these are usually established between the vendor and customer. It should be noted that materials properties can vary substantially between classes of materials (e.g., LNO and LFP) and caution should be exercised when attempting to directly compare their chemical and physical properties. While these distinctions are important for the manufacturer, this document focuses on the techniques to measure the materials properties and not their absolute or relative values. Future materials such as solid-state batteries and sulfides are beyond the scope of this document. It is beyond the scope of this document to examine the rheological properties of the cathode material dispersed in a coating slurry since such properties are influenced by the conductive additive

Battery Materials Testing Committee

Recommended Practice for Determining Material Properties of Li-Battery Cathode Active Materials

J3021_202105 (Current)

05/28/2021

This SAE Recommended Practice provides a set of test methods and practices for the characterization of lithium ion battery cathode active material. It is beyond the scope of this document to establish criteria for the test results, as these are usually established between the vendor and customer. It should be noted that materials properties can vary substantially between classes of materials (e.g., LNO and LFP) and caution should be exercised when attempting to directly compare their chemical and physical properties. While these distinctions are important for the manufacturer, this document focuses on the techniques to measure the materials properties and not their absolute or relative values. Future materials such as solid-state batteries and sulfides are beyond the scope of this document. It is beyond the scope of this document to examine the rheological properties of the cathode material dispersed in a coating slurry since such properties are influenced by the conductive additive

Battery Materials Testing Committee

Reconfigurable Electronics Based on Multiferroics and Nanomagnetism

21AERP02_0902/01/2021

Research could lead to the development of new materials with large magnetoelectric (ME) coupling for next-generation multifunctional devices, including, multi-state (neuromorphic-like) circuits and memories, and E-field tunable microwave resonators for secure communications. Air Force Research Laboratory, Arlington, Virginia Multifunctional magnetoelectric materials with high exchange represent a missing “holy grail” of materials physics. To combine polarization and magnetization in the same solid is nothing short of actually controlling the fundamental nature of electromagnetism in matter. Although magnetoelectricity (ME) is an intrinsic phenomenon in some natural materials at low temperature, such single-phase materials suffer from an extremely weak ME exchange. In contrast, composites consisting of magnetostrictive and piezoelectric phases can feature dramatically larger ME coefficients. This proposed program focuses on achieving the disruptive potential of emerging multifunctional

A Comprehensive Way to Use Bonding to Improve RF Performance of Low Noise Amplifiers

TBMG-3852602/01/2021

Is RF engineering a form of black magic? This article analyzes the challenges faced in the development of the ADH519S, an 18-GHz to 31-GHz low noise amplifier (LNA) for the aerospace market. The die used in the product development for space was originally released to the commercial industry in the LC4 package. To release this product for the space and high-reliability market and comply with MIL-PRF-38535 standards, this part was assembled using the most suitable and available hermetically sealed ceramic package. This article presents a unique solution and process education to improve RF performance via bonding. This product development process presented the following challenges:

A Comprehensive Way to Use Bonding to Improve RF Performance of LOW NOISE AMPLIFIERS

21AERP02_0502/01/2021

Is RF engineering a form of black magic? This article analyzes the challenges faced in the development of the ADH519S, an 18-GHz to 31-GHz low noise amplifier (LNA) for the aerospace market. The die used in the product development for space was originally released to the commercial industry in the LC4 package. To release this product for the space and high-reliability market and comply with MIL-PRF-38535 standards, this part was assembled using the most suitable and available hermetically sealed ceramic package. This article presents a unique solution and process education to improve RF performance via bonding. This product development process presented the following challenges: This article reviews the different methods used to overcome these challenges and how to achieve the best stability and noise figure performance from the new hermetically sealed ceramic package.

Overlap Shear Test for Automotive Type Sealant for Stationary Glass Bonding

J1529_202101 (Current)

01/07/2021

This SAE Recommended Practice defines a procedure for the construction and testing of glass to metal lap shears for determining shear strength of sealant adhesives for automotive stationary glass bonding. This procedure can also be used for fiber reinforced plastic (FRP) when used in place of metal.

Materials, Processes and Parts Council

Wear Performances of Gray Cast Iron Brake Rotor with Plasma Electrolytic Aluminating Coating against Different Pads

2020-01-162310/05/2020

Gray cast iron brake rotor experiences substantial wear during braking and contributes largely to the wear debris emissions. Surface coating on the gray cast iron rotor represents a trending approach dealing with the problems. In this research, a new plasma electrolytic aluminating (PEA) process was used for preparing an alumina-based ceramic coating with metallurgical bonding to the gray cast iron. Three different types of brake pads (ceramic, semi-metallic and non asbestos organic (NAO)) were used for tribotests. Performances of PEA coatings vs. different brake pad materials were comparatively investigated with respect to their coefficients of friction (COFs) and wear. The PEA-coated brake rotor has a dimple-like surface which promotes the formation of a thin transferred film to protect the rotor from wear. The transferred film materials come from the wear debris of the pads. The secondary plateaus are regenerated on the brake pads through compacting wear debris of the pads. The wear

Cai, Ran, Zhang, Jingzeng, Tjong, Jimi, Nie, Xueyuan

New Coating Process Lights Porous Electronics and Sensors

08/01/2020

Researchers have shown how to coat glass and plastic with porous titanium dioxide. The fabrication process is straightforward, the materials are cheap, and the ceramic’s gas sensing performance is considerably improved compared with current devices.

Nano-Infused Ceramic Can Report its own Health

TBMG-3683005/01/2020

A ceramic was developed that becomes more electrically conductive under elastic strain and less conductive under plastic strain. The material could lead to a new generation of sensors embedded into structures like buildings, bridges, and aircraft able to monitor their own health.

Additive Manufacturing Method for Sub-Microscale Three-Dimensional Structures

TBMG-3637604/01/2020

NASA Goddard Space Flight Center has developed a substantial advancement in additive manufacturing technology. The method eliminates most material restrictions, enabling fabrication of sub-microscale three-dimensional structures composed of nearly any material that is compatible with chemical vapor deposition (CVD) including metallic and ceramic materials. Current technology for the production of microscale three-dimensional structures, such as two-photon lithography, is generally limited to the use of photosensitive polymeric materials.

Fabrication and Electrical Characterization of Correlated Oxide Field Effect Switching Devices for High Speed Electronics

TBMG-3660604/01/2020

Metal insulator transitions (MITs) in oxides are an intriguing problem from both a fundamental materials physics and an applied technology perspective. Though the precise roles of electron correlations and lattice distortions on the phase transition remains an active area of research, many recent theoretical studies have suggested intimate interplay among the orbital splitting/polarization, correlation effects, and Peierls dimerization in the 3d1 system. Occupied states have been probed by x ray photoelectron spectroscopy (XPS), and a rough structure of unoccupied 3d-like states have been deduced by O K-edge x-ray absorption measurements. NbO2, a 4d1 system, like VO2 crystallizes in a distorted rutile type structure with Nb dimers and undergoes a temperature induced MIT, albeit at a considerably higher temperature of ~1083 K. It is commonly accepted that because 4d orbital valence states are more dispersed in both space and energy, Mott physics is less important in 4d transition metal

Alternatives to Cadmium Plating

AIR4160B (Current)03/24/2020

To document and provide access to information obtained by an industry survey.

G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies

Celebrating Women in Engineering & Science: Renee Bernstein, CEO, Cotronics Corporation

TBMG-3616703/01/2020

Welding Ceramics with Lasers

TBMG-3599202/01/2020

Ceramics have been challenging to weld together because they need extremely high temperatures to melt, exposing them to extreme temperature gradients that cause cracking. Ceramic materials are biocompatible, extremely hard, and shatter-resistant, making them ideal for biomedical implants and protective casings for electronics.

Thermally Conductive Polymer Films

TBMG-3597702/01/2020

Polymers are commonly used for thermal insulation as they are excellent at trapping heat. Thin polymer films were developed that conduct heat — an ability normally associated with metals. The films, which are thinner than plastic wrap, conduct heat better than many metals including steel and ceramic.

Mechanical and Corrosion Behaviour of Al 7075 Composite Reinforced with TiC and Al ₂ O ₃ Particles

2019-28-009410/11/2019

Various research regarding new types of fabrication and modifications of Aluminium alloy to improve the existing properties are going on. The wide range application of aluminium alloy is in aerospace and Automobile Industries. The demand for this material improved by mechanical properties with little to zero increment in weight. The current work is based on the fabrication of hybrid aluminium metal matrix composites with the addition of TiC (Titanium Carbide) and Al2O3 (Aluminium Oxide) reinforcement particle using stir casting technique. Three types of hybrid composite samples were prepared based on the weight percentage 5% Al2O3+0% TiC (sample-1), 8% Al2O3 + 12% TiC (sample-2), 20% Al2O3+15% TiC (sample-3). The objective of the study is to analyze the mechanical and corrosion properties of the hybrid composite with the influence of the reinforcement and varying the weight fraction of the particles. Overall, It is observed that a gradual increase in the hardness value in sample-1(83

Jaiswal, Subham, Rajamurugan, Govindasamy, Krishnasamy, Prabu, Shaswat, Yashwardhan, Kaushik, Mishra

Low-Cost and Light-Weight Fireproof Material for Aircraft: Interior, Cargo Compartment and Unit Load Device (Fire and Explosion Container ULD)

2019-01-185709/16/2019

Fire is a dramatic issue in aircraft nowadays, especially for composite air craft. An additional issue is the dangerous use of flammable Li-Ion batteries in many devices. To minimize fire issues, it is proposed to produce aircraft interiors, fire doors, cargo bay walls, and cargo containers that are able to contain a fire inside them, with our ceramic composite called TOUGHCERAM®. It is low-cost, ceramic, damage tolerant, and flexible between minus 100°C and plus 350°C. TOUGHCERAM® poly-crystalizes between 20°C and 110°C and can be reinforced with fibers (carbon or basalt). It will survive 90 minutes under direct contact with a propane torch of 1900°C. TOUGHCERAM® does not burn or smoke. This paper will explain how it is possible to develop a fully mineral-ceramic offering with unique mechanical, fire, and blast containment properties.

Ceramic Bound Materials: A Suitable Solution for Light Brakes

2019-01-210909/15/2019

A ceramic bound matrix has been investigated to be used as a friction material. The materials were produced by means of ceramic technology using frits containing silicates, and ceramic friction modifiers such as tin oxide, zircon, iron oxide, magnesium oxide. Four formulations were tested by means of a tribometer (pin-on-disc tester) using a gray cast iron counterpart. Test section included speeds between 1 and 12 ms-1, and loads between 25 and 400 N. The coefficient of friction of the tested specimens were between 0.7 and 0.4, and exhibited sensitivity to speed at low loads (25 N), while they are quite stables at high loads (400N). The characterization of the tribolayers was carried out by means of scanning electron microscopy. The four developed materials were named A, B, C, and D. They exhibited different wear rates and coefficients of friction. All the materials exhibited sensitivity to speed, while showed a lower sensitivity to load. The coefficient of friction level seems to be

Dante, Roberto C., Cotilli, Edoardo, Conforti, Michael, Cotilli, Mario, Serrano-Posada, José Carlos, Schramm, Tobias, Ostermeyer, Georg-Peter, Dastrù, Marco

Heat Transfer Analysis of Catalytic Converters during Cold Starts

2019-24-016309/09/2019

The transient heat transfer behavior of an automotive catalytic converter has been simulated with OpenFOAM in 1D. The model takes into consideration the gas-solid convective heat transfer, axial wall conduction and heat capacity effects in the solid phase, but also the chemical reactions of CO oxidation, based on simplified Arrhenius and Langmuir-Hinshelwood approaches. The associated parameters are the results of data in literature tuned by experiments. Simplified cases of constant flow rates and gas temperatures in the catalyst inflow have been chosen for a comprehensive analysis of the heat and mass transfer phenomena. The impact of inlet flow temperatures and inlet flow rates on the heat up characteristics as well as in the CO emissions have been quantified. A dimensional analysis is proposed and dimensionless temperature difference and space-time coordinates are introduced. Using this suitably modified coordinates, for the case of negligible axial solid conduction, computed solid

Papetti, Viola, Dimopoulos Eggenschwiler, Panayotis, Della Torre, Augusto, Montenegro, Gianluca, Onorati, Angelo, Koltsakis, Grigorios

Thermal Conductivities of Some Polymers and Composites

TBMG-3486808/01/2019

Thermoset polymers are good electrical insulators that are used in applications ranging from electronics to composite armor. They are rather poor thermal conductors, however.

High-Temperature Dielectric Nanocomposite

TBMG-3489908/01/2019

A nanocomposite was developed that could be a superior high-temperature dielectric material for flexible electronics, energy storage, and electric devices. The nanocomposite combines one-dimensional polymer nanofibers and two-dimensional boron nitride nano-sheets. The nanofibers reinforce the self-assembling material while the white graphene nanosheets provide a thermally conductive network that allows it to withstand the heat that breaks down common dielectrics, the polarized insulators in batteries, and other devices that separate positive and negative electrodes.

Thermal Conductivities of Some Polymers and Composites

19AERP08_0908/01/2019

Assessing the performance of polymers used in structural armor and filament winding applications. Army Research Laboratory, Aberdeen Proving Ground, Maryland Thermoset polymers are good electrical insulators that are used in applications ranging from electronics to composite armor. They are rather poor thermal conductors, however. For encapsulation of electronic components and devices, there is a huge amount of literature on filled polymers, particularly epoxies. One source provides a recent review of thermal conductivity (Kt) of filled polymers with emphasis on carbon nanotube loading. As an example of a low Kt polymer, a Kt of 0.3 watts per meter per degree kelvin (W/MK) for unfilled polyurethane from an unidentified source has been cited, with higher values for filled resin. Measurements have also been reported on particle-filled polypropylene with a neat resin Kt of 0.27 W/MK. These thermal conductivities are higher than those of most epoxies, and much lower than those of metals

Failsafe Linear Magnetic Brakes

TBMG-3411304/01/2019

Linear permanent magnet brakes, also known as eddy current brakes, are a failsafe, power-free deceleration system that is used in conjunction with a metal reaction plate. Ceramic or rare earth magnets are bonded to a steel back iron plate; no input power is required.

Metallic Hollow Nanoparticle Fabrication

TBMG-3415604/01/2019

NASA Langley Research Center has developed new methods for fabricating hollow nanoparticles using dendrimer molecules. Dendrimers are used as templates to control the size, stability, and solubility of these metallic nanoparticles ranging in metal lining thicknesses from less than 5 nm to several tens of nm.

Contaminant-Free Steel

TBMG-3360801/01/2019

For many highly stressed engineering applications like bearings and gears, contaminated steel parts can lead to devastating outcomes such as an emergency shutdown or the end of a mission. Ensuring that these critical components are as homogeneous as possible and free from porosity and other flaws is vital to performance, yet conventional steelmaking processes have multiple pathways of entry for unwanted contamination.

Alloy, Corrosion and Heat-Resistant, Sheet, Strip, and Plate 29Fe - 22Cr - 21Ni - 18.5Co - 3.2Mo - 2.8W - 0.78Ta - 0.30Al - 0.05Zr - 0.05La - 0.20N Solution Heat Treated

AMS5874C-TEST-REC (Historical)10/10/2018

This specification covers a corrosion and heat-resistant alloy in the form of sheet, strip, and plate.

AMS F Corrosion Heat Resistant Alloys Committee

Alloy, Corrosion and Heat-Resistant, Sheet, Strip, and Plate 29Fe - 22Cr - 21Ni - 18.5Co - 3.2Mo - 2.8W - 0.78Ta - 0.30Al - 0.05Zr - 0.05La - 0.20N Solution Heat Treated

AMS5874C (Historical)

10/10/2018

This specification covers a corrosion and heat-resistant alloy in the form of sheet, strip, and plate.

AMS F Corrosion Heat Resistant Alloys Committee

High-Kinetic-Energy Penetrator Shielding and High-Wear-Resistance Materials Fabricated with Boron Nitride Nanotubes and BNNT Polymer Composites

TBMG-3283109/01/2018

In recent years, anti-penetration materials have been more widely used for armor, bulletproof vests, and micrometeoroid and orbital debris protection layers for space-suits, space vehicles, and structures. Micrometeoroids develop very high kinetic energies as they travel through space, and pose a significant hazard to spacecraft and astronauts. The velocities of micrometeorites can reach 20 kilometers per second prior to impact on the lunar surface. Therefore, a new protective system utilizing new materials is needed to effectively shield the space vehicles and structures against the high-kinetic-energy penetrators as well as provide penetration-resistant spacesuits. In order to maximize the protection ability against high-kinetic-energy penetrators, the following two major material properties should be considered: high hardness for rebounding and/or gross mechanical deformation of the penetrator, and high toughness for effective energy absorption during the mechanical deformation (and

Fabrication and Mechanical Properties of Alumina Nanoparticle Reinforced Magnesium Metal Matrix Composite by Stir Casting Method

2018-28-009807/09/2018

In the present experimental investigation magnesium based alloy was prepared by mixing magnesium powder and aluminium powder in the ratio 65:35. The prepared magnesium alloy is used as the matrix material. Metal matrix composites were prepared by stir casting route. The composite was prepared by reinforcing 50 nm alumina nanoparticle so that the final composite contains 5, 10 and 15 wt.% alumina. Mechanical properties such as tensile strength, yield strength, impact strength and hardness were evaluated. Significant improvement was observed in impact strength and hardness value. The result showed that magnesium alloy with 5 wt.% alumina nanoparticle has a maximum impact strength of 25.2 J and hardness value 63.86 Hv respectively. Tensile strength and yield strength shows marginal increase in value.

T, Thirugnanasambandham, J, Chandradass, Sethupathi, P Baskara, Jesu Martin, Leenus

Coefficient of Thermal Expansion and Elastic Modulus of SIC _P /AL ₂ O ₃ Ceramic Matrix Composites Prepared by Directed Metal Oxidation Process

2018-28-004707/09/2018

The present paper, it is aimed to prepare SiCp/Al2O3 ceramic matrix composites using Directed Metal Oxidation process large enough dimension specimens for the measurement of physical properties. Continuous oxidation of an Aluminum alloy with suitable dopant along with a preform of SiC has lead to the formation of alumina matrix surrounding silicon carbide particulates. SiCp/Al2O3 ceramic matrix composites fabricated by the Directed Metal Oxidation process, possess required physical properties such as coefficient of thermal expansion (CTE) and elastic modulus, all at an affordable cost of fabrication. Al2O3 matrix composites reinforced with different volume fractions of SiC particulates were investigated for physical properties such as coefficient of thermal expansion (CTE) and elastic modulus. The composites with SiC volume fraction of 0.43 were found to possess a CTE as of as 5.0 x 10−6/K and an elastic modulus of 262 GPa.

Malkapuram, Dr Devaiah

Products of Tomorrow: June 2018

TBMG-2904306/01/2018

This column presents technologies that have applications in commercial areas, possibly creating the products of tomorrow. To learn more about each technology, see the contact information provided for that innovation.

Ferroelectric Material Improves Ultrasound

TBMG-2894505/01/2018

Development of a theoretical basis for ultrahigh piezoelectricity in ferroelectric materials has led to a new material with twice the piezo response of any existing commercial ferroelectric ceramics.

Magnesium Alloy, Processes for Pretreatment and Prevention of Corrosion on

AMSM3171 (Historical)02/25/2018

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.

AMS B Finishes Processes and Fluids Committee

Conductive, High-Toughness Oxides Deposited by Plasma Spray-Physical Vapor Deposition (PS-PVD)

TBMG-2832502/01/2018

Oxide coatings deposited in Glenn Research Center's Plasma Spray-Physical Vapor Deposition (PS-PVD) facility can be processed to be mechanically tough (erosion-resistant) and electrically conductive at room temperature. The electrically conductive phase contained within the oxide (MO2) coatings is a metastable suboxide (MO) that has not been formed in significant volume under any other known methods. Content of the electrically conductive phase can be varied in addition to the microstructure, which can be columnar, planar, or a combination of the two depending on the processing conditions. Upon exposing the material to moderate temperatures (>300 °C), the metastable phase is further oxidized (to MO2) and the material becomes insulating, but retains its high toughness and microstructure.

Non-Destructive Additive Manufacturing Characterization Coupon

TBMG-2814801/01/2018

Additive manufacturing (AM) material assurance has relied upon traditional test coupons and testing methods that work well for wrought materials, but fail to address the unique and not as well-known characteristics of AM parts. A new standardized, integrated test coupon was designed specifically for AM that allows for non-destructive testing of material properties, allowing for repeated testing through a series of environments in order to characterize part reliability.

New Products & Services: December 2017 Aerospace Manufacturing & Fabrication

TBMG-2793912/01/2017

Flexible, Printable Electronics for Sensor Arrays

TBMG-2778911/01/2017

Printable electronics — flexible circuitry that is deposited on some type of plastic substrate — has been a major area of research for decades. But the ability to print the substrate itself greatly increases the range of devices the technique can yield.

Ultralight, Scalable, High-Temperature-Resilient Ceramic Nanofiber Sponges

TBMG-2752209/01/2017

Researchers have made ultralight, highly porous, compressible, and heat-resistant sponge-like materials from nanoscale ceramic fibers. The highly deformable material is made by tangling ceramic nanofibers into a sponge. The method used is inexpensive and scalable for making large quantities.

Composite Materials Handbook Volume 5 - Revision A

R-42606/29/2017

The fifth volume of this six-volume compendium publishes technical guidance and properties on ceramic matrix composite material systems. The selected guidance on technical topics related to this class of composites includes material selection, processing, characterization, testing, data reduction, design, analysis, quality control, application, case histories, and lessons learned of typical ceramic matrix composite materials. Volume 5, which covers ceramic matrix composites, supersedes MIL-HDBK-17-5 of June 17, 2002. The Composite Materials Handbook, referred to by industry groups as CMH-17, is an engineering reference tool that contains over 1,000 records of the latest test data for polymer matrix, metal matrix, ceramic matrix, and structural sandwich composites. CMH-17 provides information and guidance necessary to design and fabricate end items from composite materials. It includes properties of composite materials that meet specific data requirements as well as guidelines for

Composites and Metal Bonding Glossary

AIR4844C (Current)06/20/2017

The following terminology has been generated by the ATA/IATA/SAE Commercial Aircraft Composite Repair Committee (CACRC) and provides terminology for design, fabrication, and repair of composite and bonded metal structures.

AMS CACRC Commercial Aircraft Composite Repair Committee

Highly Porous and Mechanically Strong Ceramic Oxide Aerogels

TBMG-2683605/01/2017

NASA's Glenn Research Center (GRC) has developed and produced ultra-lightweight polymer cross-linked aerogels (X-Aerogels). These mechanically robust, highly porous, low-density materials are three times denser than native aerogels, but more than 100 times stronger. Aerogels are ultra-lightweight glass foams with extremely small pores (on the order of 10 to 50 nanometers). These materials are extremely good thermal insulators, with R values ranging from 2 to 10 times higher than polymer foams. Unlike multilayer insulation, aerogels do not require a high vacuum to maintain their low thermal conductivity, and can function as good thermal insulators at ambient pressure. In addition, they are good electrical insulators and have low refractive indices, both approaching values close to air. Aerogels are also excellent vibration-damping materials. Traditional aerogels, however, suffer fragility and poor environmental durability.

A Modeling Analysis of Fibrous Media for Gasoline Particulate Filters

2017-01-096703/28/2017

With an emerging need for gasoline particulate filters (GPFs) to lower particle emissions from gasoline direct injection (GDI) engines, studies are being conducted to optimize GPF designs in order to balance filtration efficiency, backpressure penalty, filter size, cost and other factors. Metal fiber filters could offer additional designs to the GPF portfolio, which is currently dominated by ceramic wall-flow filters. However, knowledge on their performance as GPFs is still limited. In this study, modeling on backpressure and filtration efficiency of fibrous media was carried out to determine the basic design criteria (filtration area, filter thickness and size) for different target efficiencies and backpressures at given gas flow conditions. Filter media with different fiber sizes (8 - 17 μm) and porosities (80% - 95%) were evaluated using modeling to determine the influence of fiber size and porosity. A comparison of design criteria for fibrous filters and their ceramic counterparts

Liu, Xin, Kim, Jeong, Chanko, Timothy, Lambert, Christine, Pakko, James

Development of a New Ceramic Substrate with Gas Flow Control Functionality

2017-01-091903/28/2017

Emission regulations in many countries and regions around the world are becoming stricter in reaction to the increasing awareness of environment protections, and it has now become necessary to improve the performance of catalytic converters to achieve these goals. A catalytic converter is composed of a catalytically active material coated onto a ceramic honeycomb-structured substrate. Honeycomb substrates play the role of ensuring intimate contact between the exhaust gas and the catalyst within the substrate’s flow channels. In recent years, high-load test cycles have been introduced which require increased robustness to maintain low emissions during the wide range of load changes. Therefore, it is extremely important to increase the probability of contact between the exhaust gas and catalyst. To achieve this contact, several measures were considered such as increasing active sites or geometrical surface areas by utilizing substrates with higher cell densities or larger volumes. These

Yoshida, Takeru, Suzuki, Hiromasa, Aoki, Yuki, Hayashi, Naohiro, Ito, Kenichi

The Heavy Impact of Advanced Lightweight Materials

TBMG-2651403/01/2017

Historically, high-strength materials have been heavy and dense. The need for high-strength but lightweight materials has become more widespread when designing everything from vehicles and aircraft, to buildings and wind turbines. These advanced materials are enabling engines to operate efficiently at higher temperatures, use less fuel, and emit fewer pollutants, as well as finding uses in many other applications.

Method for Fabricating Diamond-Dispersed, Fiber-Reinforced Composite Coating on Low-Temperature Sliding Thrust Bearing Interfaces

TBMG-2634602/01/2017

Innovators at NASA's Glenn Research Center have developed a method for fabricating a fiber-reinforced diamond composite coating on the surfaces of sliding thrust bearings at low and cryogenic temperatures. The innovative composite coating is a mixture of diamond particles, organic chemicals, and fibers or fabrics. The diamond particles provide high hardness, and the fibers and binding matrix provide high-fracture toughness. Glenn's fabrication method can be tailored to meet a range of performance requirements for lightweight, low-temperature sliding thrust bearing applications. For example, the volume fraction of diamond particles can be increased to enhance the hardness of the composite coating, or the volume fraction of binding matrix can be increased to enhance its crack or fracture resistance. Glenn's method offers a diamond composite coating that is more cost-effective, wear-resistant, and fracture-tough than existing alternatives.

Development of Aluminum Composite Automotive Brake Rotors

2016-01-193709/18/2016

Aluminum metal matrix composite brake rotors with a selective ceramic function reinforcement gradient (FRG) have been developed for automotive applications. This paper will highlight the design, manufacturing, and testing of the rotors. Weight saving of an aluminum composite rotor in comparison to an industry standard cast iron rotor is 50-60%. With this material change comes design considerations to manage rotor temperature, rotor surface integrity, and friction. Manufacturing methods to meet these design constraints were needed to develop a viable high performance aluminum composite rotor. High pressure squeeze casting with soluble coring techniques were developed to incorporate the selective FRG MMC rotors. Dynamometer testing was performed, concentrating on brake friction and temperature to evaluate the macro and micro interfaces in the rotors. The rotors’ testing results indicate that a functional reinforced aluminum metal matrix composite rotor is viable option for front and rear

Erva, Taylor, Loukus, Adam, Luskin, Luke

Flexible Ablator for Thermal Protection

TBMG-2535009/01/2016

NASA has developed a class of low-density, flexible ablators that can be fabricated into heat-shields capable of being packaged, stowed, and deployed in space. The key characteristics of this new ablative thermal protection system (TPS) are its flexibility, conformability, and tailor-ability. Flexibility allows the material to be stowed in the shroud of a launch vehicle and deployed in space, without compromising functionality. Conformability allows the material to be attached to a curved surface without precise and expensive machining. Tailor-ability allows the density and composition to be optimized for the requirements. This flexible TPS can be used to cover and thermally protect a large, blunt shape that provides aerodynamic drag during hyper-velocity atmospheric flight. It can be used with minimal modification for large aeroshells whose deployment relies mainly on mechanical means and through inflation. Such devices are called Hypersonic Inflatable Aerodynamic Decelerators (HIADs

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