Space telescope boasts a dozen flight mirrors
May 3, 2016
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One dozen flight mirrors are now installed on NASA's James Webb Space Telescope, out of the eighteen mirror segments that make up the primary mirror. The assembly of the primary mirror is an important milestone for the Webb telescope, but is just one component of this huge and complex observatory.
Since December 2015, scientists and engineers have been working tirelessly to install all the primary mirror segments onto the telescope structure in the large clean room at NASA's Goddard Space Flight Center, Greenbelt, Md. The twelfth mirror was installed on January 2, 2016.
"This milestone signifies that all of the hexagonal shaped mirrors on the fixed central section of the telescope structure are installed and only the three mirrors on each wing are left for installation," says Lee Feinberg at NASA Goddard. "The incredibly skilled and dedicated team assembling the telescope continues to find ways to do things faster and more efficiently."
Each hexagonal-shaped segment measures just over 4.2 ft (1.3 m) across and weighs approximately 88 lb (40 kg). After being pieced together, the 18 primary mirror segments will work together as one large 21.3-ft (6.5-m) mirror. The primary mirror will unfold and adjust to shape after launch. The mirrors are made of ultra-lightweight beryllium. The mirrors are placed on the telescope's backplane using a robotic arm, guided by engineers. The full installation is expected to be completed soon.
The mirrors were built by Ball Aerospace & Technologies Corp., Boulder, Colorado. Ball is the principal subcontractor to Northrop Grumman, Falls Church, Va., for the optical technology and lightweight mirror system. The installation of the mirrors onto the telescope structure is performed by Harris Corp., Rochester, N.Y. Harris Corp. leads integration and testing for the telescope.
While the mirror assembly is a very significant milestone, there are many more steps involved in assembling the Webb telescope. The primary mirror and the tennis-court-sized sunshield are the largest and most visible components of the Webb telescope. However, there are four smaller components that are less visible, yet critical. The instruments that will fly aboard Webb—cameras and spectrographs with detectors able to record extremely faint signals—are part of the Integrated Science Instrument Module (ISIM), which is currently undergoing its final cryogenic vacuum test and will be integrated with the mirror later this year.
The near infrared spectrograph (NIRSpec) has programmable microshutters which enable observation up to 100 objects simultaneously. The near infrared camera (NIRCam) is equipped with coronagraphs, instruments that allow astronomers to take pictures of very faint objects around a central bright object, like stellar systems.
The Webb telescope also has a cryocooler for cooling the mid-infrared instrument (MIRI) to a very cold 7 K so they can work. MIRI has both a camera and a spectrograph that sees light in the mid-infrared region of the electromagnetic spectrum, with wavelengths that are longer than our eyes see. There's also the Fine Guidance Sensor (FGS) allows Webb to point precisely, so that it can obtain high-quality images.
Over the next two years in preparation for launch, various components of the Webb telescope will endure rigorous environmental and optical testing. The sunshield will be joined with the spacecraft bus (main structure) followed by more testing. The Webb telescope is planned for launch in 2018.
The James Webb Space Telescope is the scientific successor to NASA's Hubble Space Telescope. It will be the most powerful space telescope ever built. Webb is an international project led by NASA with its partners, the European Space Agency, and the Canadian Space Agency.
Image caption — One dozen (out of 18) flight mirror segments that make up the primary mirror on NASA's James Webb Space Telescope have been installed at NASA's Goddard Space Flight Center. Courtesy of NASA/Chris Gunn.
One dozen flight mirrors are now installed on NASA’s James Webb Space Telescope, out of the eighteen mirror segments that make up the primary mirror.
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Rick Sisson Wins Trustees Research & Creative Scholarship Award
April 28, 2016
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ASM Fellow Richard D. Sisson has received Worcester Polytechnic Institute's 2016 Board of Trustees' Award for Outstanding Research and Creative Scholarship. The award recognizes continuing excellence in research and scholarship by faculty members over a period of at least five years.
Prof. Sisson is the George F. Fuller Professor of Mechanical Engineering, director of Worcester Polytechnic Institute's Manufacturing and Materials Engineering Programs, and technical director of the WPI Center for Heat Treating Excellence.
He is internationally recognized for his research in materials science and engineering, as well as manufacturing. His pioneering work spans several areas of physical metallurgy, and he has written more than 250 journal articles and 250 technical presentations.
Prof. Sisson is currently principal investigator for a multi-million-dollar, multi-institution project aimed at developing new metallurgical methods and new lightweight alloys to help the military build more effective and durable vehicles and systems. He has won numerous national and international awards, and has served as president of the ASM Heat Treating Society.
wpi.edu/+chte
ASM Fellow Richard D. Sisson has received Worcester Polytechnic Institute’s 2016 Board of Trustees’ Award for Outstanding Research and Creative Scholarship.
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Heat-treated powder metallurgy titanium alloy has higher strength, lower cost
April 13, 2016
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Pacific Northwest National Laboratory, Richland, Wash., announces that its research team has improved the strength of a titanium alloy by producing it via powder metallurgy and heat treating it at different temperatures, then quenching in cold water.
Five decades ago, metallurgists created an alloy named Ti185 by blending titanium with low-cost iron, aluminum, and vanadium. However, superior strength was observed for this alloy only in some places, and the alloy had a tendency to clump. Iron clustered in some areas, leading to beta fleck defects, making the alloy unsuitable for reliable commercial production.
Subsequently, in a study carried out about six years ago, the PNNL researchers and its collaborators devised a low-cost powder metallurgy process for the industrial-scale production of the alloy. They used titanium hydride powder instead of molten titanium as the starting material, reducing the energy requirements significantly and cutting the process time in half. ADMA co-developed the method with PNNL metallurgist Curt Lavender. The company sells advanced materials such as the titanium hydride powder to industries, including aerospace.
In their earlier study, the researchers had already demonstrated the superior mechanical properties of the titanium alloy created from their low-cost process. In the new study, they explored how to make even stronger titanium alloys. The team was able to gain insights into the nanostructure of the alloy by using a unique atom probe imaging approach and powerful electron microscopes.
Using electron microscopy, the team observed the microstructure of the alloy at a resolution of hundreds of nanometers. The atom probe tomography system at the Environmental Molecular Sciences Laboratory, a DOE Office of Science User Facility located at PNNL, was used to observe the arrangement of individual atoms in 3D.
The researchers found that their optimized heat-treating process produced an alloy with an alpha phase, consisting of micron and nanometer -size precipitate regions, in a matrix of beta phase. Each region has higher concentrations of certain elements. The aluminum and titanium atoms are found inside the nano-sized alpha phase precipitates, whereas vanadium and iron are in the beta phase.
"We found that if you heat treat it first at a higher temperature before a low -temperature heat treatment step, you could create a titanium alloy 10 to 15% stronger than any commercial titanium alloy currently on the market, and that it has roughly double the strength of steel," says Arun Devaraj, Materials Scientist at PNNL
"This alloy is still more expensive than steel, but with its strength-to-cost ratio, it becomes much more affordable with greater potential for lightweight automotive applications," added Vineet Joshi, who serves as a metallurgist at PNNL.
www.pnnl.gov
Pacific Northwest National Laboratory, Richland, Wash., announces that its research team has improved the strength of a titanium alloy by producing it via powder metallurgy and heat treating it at different temperatures, then quenching in cold water.
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3D-printed metal aircraft parts
April 8, 2016
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Alcoa, Pittsburgh, entered into an agreement with Airbus, France, to supply 3D-printed metal parts for commercial aircraft. The parts will be produced using comprehensive capabilities—from multimaterial alloy development to additive manufacturing and aerospace parts qualification. The first additive manufactured parts are expected to be delivered midyear.
The agreement draws on Alcoa's aerospace experience and new technologies gained through its recent acquisition of RTI. The company also recently invested in 3D-printing and metallic powder production capabilities at its technical center outside of Pittsburgh.
Last year, Alcoa acquired RTI International Metals (RTI)—now known as Alcoa Titanium & Engineered Products (ATEP)—which grew its additive manufacturing capabilities to include 3D-printed titanium and specialty metals parts produced at ATEP's Austin, Texas facility. The Airbus agreement draws on these capabilities as well as ATEP's titanium ingot melting and billetizing, machining, finishing, and inspection technologies.
Alcoa will use advanced CT scan and hot isostatic pressing (HIP) capabilities at its advanced aerospace facility in Whitehall, Mich. HIP strengthens the metallic structures of traditional and additive manufactured parts made of titanium and nickel based superalloys. Through a $22 million investment in the technology, Alcoa today owns and operates one of the largest aerospace HIP technology complexes in the world.
Additionally, Alcoa is bolstering its additive manufacturing capabilities through a $60 million expansion in advanced 3D-printing materials and processes, including metallic powders. The expansion is located at the Alcoa Technical Center near Pittsburgh.
Alcoa, Pittsburgh, entered into an agreement with Airbus, France, to supply 3D-printed metal parts for commercial aircraft.
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Tribogenics XRF analyzer is based on a cartridge system instead of glass X-ray tube
January 25, 2016
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Tribogenics, Los Angeles, Calif., introduces the Watson XRF analyzer, in which the company says conventional glass X-ray tubes are replaced with an X-Change cartridge system that makes changing cartridges "as easy as changing the ink in an inkjet printer." It enables quick and accurate identification of 32 elements, and can reportedly identify most of the popular aluminum alloys in less than twenty seconds.
Watson software is said to be able to identify more than 436 metal alloys and provide identification and analysis of more than 32 of the most common elements used in tens of thousands of alloy grades.
Watson uses the Android operating system and supports the mobile user interface concepts and wireless communication interfaces. This permits a wide range of personnel, with varying levels of skill and knowledge, to quickly and accurately use the Watson for all types of applications that can use hand-held XRF technology. The software supports configuring the XRF instrument and performs automatic internal calibration without the need for a trained technician or carrying around bulky calibration discs.
It takes advantage of the latest in smartphone design and software, and costs $10,000. An intuitive interface means that it's easy for anyone to use without any special training. Watson is Wi-Fi enabled for automatic software updates, and comes with integrated market pricing, keeping users current on all local alloy market prices.
www.tribogenics.com
Tribogenics, Los Angeles, Calif., introduces the Watson XRF analyzer, in which the company says conventional glass X-ray tubes are replaced with an X-Change cartridge system that makes changing cartridges “as easy as changing the ink in an inkjet printer.”
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One Minute Mentor: Secondary Hardening in Tool Steels
January 22, 2016
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As shown schematically in the graph, high-temperature hardness is made possible only by a very important straightening mechanism: secondary hardening, promoted by the precipitation of fine alloy carbides. The stronger the secondary hardening (meaning more intense carbide precipitation), the higher the tempering resistance of hot-work tool steels. Such precipitation intensity depends on the amount of alloy elements in solid solution, which is related to the alloy composition and heat treating practice obtained by molybdenum, vanadium, or tungsten alloying.
The graph shows a schematic of hardness after tempering and the effect of secondary hardening in high-alloy steels. Observe that high-temperature hardness is only possible through precipitation hardening caused by alloy carbides (secondary hardening). At low temperatures, hardness is less than martensite due to the presence of retained austenite, which is eliminated after high-temperature tempering.
Volume 4D, Heat Treating of Irons and Steels ⇒ Tool Steels ⇒ Heat Treating of Hot-Work Tool Steels ⇒ Introduction
As shown schematically in the graph, high-temperature hardness is made possible only by a very important straightening mechanism: secondary hardening, promoted by the precipitation of fine alloy carbides.
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Tresa Pollock named Principal Editor for Metallurgical and Materials Transactions
January 19, 2016
Source: ASM International
ASM International, Materials Park, Ohio, announces that the new principal editor of the Metallurgical and Materials Transactions (Met Trans) family of journals will be Dr. Tresa M. Pollock, an internationally recognized leader in the science and technology of advanced structural alloys.
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Metal powders are potential replacement for fossil fuels
December 17, 2015
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Can you imagine a future where your car is fueled by iron powder instead of gasoline? Metal powders, produced using clean primary energy sources, could provide a more viable long-term replacement for fossil fuels than other widely discussed alternatives, such as hydrogen, biofuels or batteries, according to a study researchers at McGill University, Canada.
"Technologies to generate clean electricity—primarily solar and wind power—are being developed rapidly; but we can't use that electricity for many of the things that oil and gas are used for today, such as transportation and global energy trade," says Professor Jeffrey Bergthorson.
"Biofuels can be part of the solution, but won't be able to satisfy all the demand; hydrogen requires big, heavy fuel tanks and is explosive, and batteries are too bulky and don't store enough energy for many applications," says Bergthorson. "Using metal powders as recyclable fuels that store clean primary energy for later use is a very promising alternative solution."
Novel concept
The research includes other McGill researchers and a European Space Agency scientist in the Netherlands, lays out a novel concept for using tiny metal particles—similar in size to fine flour or icing sugar—to power external-combustion engines.
Unlike the internal-combustion engines used in gasoline-powered cars, external-combustion engines use heat from an outside source to drive an engine. External-combustion engines, modern versions of the coal-fired steam locomotives that drove the industrial era, are widely used to generate power from nuclear, coal or biomass fuels in power stations.
The idea of burning metal powders is nothing new – they've been used for centuries in fireworks, for instance. Since the mid-20th century, they've also been used in rocket propellants, such as the space shuttle's solid-fuel booster rockets. But relatively little research has been done in recent decades on the properties of metal flames, and the potential for metal powders to be used as a recyclable fuel in a wide range of applications has been largely overlooked by scientists.
Recyclable after combustion
The idea put forward by the McGill team takes advantage of an important property of metal powders: when burned, they react with air to form stable, nontoxic solid-oxide products that can be collected relatively easily for recycling – unlike the CO2 emissions from burning fossil fuels that escape into the atmosphere.
Using a custom-built burner, the team demonstrated that a flame can be stabilized in a flow of tiny metal particles suspended in air. Flames from metal powders "appear quite similar" to those produced by burning hydrocarbon fuels, according to researchers. "The energy and power densities of the proposed metal-fueled heat engines are predicted to be close to current fossil-fueled internal combustion engines, making them an attractive technology for a future low-carbon society."
Iron could be the primary candidate for this purpose. Millions of tons of iron powders are already produced annually for the metallurgy, chemical and electronic industries. And iron is readily recyclable with well-established technologies, and some novel techniques can avoid the carbon dioxide emissions associated with traditional iron production using coal.
Next step: building a prototype
While laboratory work at McGill and elsewhere has shown that the use of metal fuels with heat engines is technically feasible, no one has yet demonstrated the idea in practice. The next step toward turning the lab findings into usable technology, therefore, will be "to build a prototype burner and couple it to a heat engine," Bergthorson says. "Developing metal recycling processes that don't involve CO2 emissions is also critical."
David Jarvis, head of strategic and emerging technologies at the European Space Agency, adds: "We are very interested in this technology because it opens the door to new propulsion systems that can be used in space and on earth. The shift away from fossil fuels for vehicle propulsion is a clear trend for the future. While not perfected and commercialized today, the use of low-cost metallic fuels, like iron powder, is a worthy alternative to petrol and diesel fuels. If we can demonstrate, for the first time, an iron-fueled engine with almost zero CO2 emissions, we believe this would then trigger even more innovation and cost reduction in the near future."
Research on metal combustion at McGill has been funded over the past 20 years by the Natural Sciences and Engineering Research Council of Canada, the Canadian Department of National Defence, the U.S. Defense Threat Reduction Agency, the Canadian Space Agency, the European Space Agency, Martec Ltd. (Halifax, NS), and the Trottier Institute for Sustainability in Engineering and Design.
Image caption — Stabilized flames of different metal powders burning with air, compared to a methane-air flame.
Can you imagine a future where your car is fueled by iron powder instead of gasoline?
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WPI team studies how cracks form in aircraft wings and fuselages
November 25, 2015
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Worcester Polytechnic Institute, Mass., announces that a research team will conduct comprehensive testing and characterization studies to understand and monitor how stress and fatigue cause microscopic damage to form in metal components. Specifically, the researchers will study how tiny cracks are initiated and then grow in aircraft components as they are subjected to repetitive strains and stresses similar to those that wings, fuselages, and other aircraft components experience in service.
A new imaging system enables the team to view the initiation and propagation of cracks at the nanometer scale while metal samples are stressed in a servo-hydraulic testing machine. Fatigue cracks can be detected at the surface of samples by imaging and within the microstructure by electromagnetic induction.
With the knowledge gained through laboratory testing, advanced characterization, and computational modelling, the team is looking to develop new lightweight metal alloys that are more resistant to cracking, or in which small cracks are less likely to expand into larger fissures. In addition, they hope to be able to develop algorithms that will make it possible to predict when servicing will be required, based on the state of stress and the rate of crack progression.
Team leader Prof. Diana Lados says the technology can be incorporated into sensors that could be attached to critical components in airplanes to detect and monitor fatigue damage in real time. Currently, aircraft are taken out of service at set intervals to be inspected for fatigue-related cracking. By monitoring aircraft components continuously, and using the predictive algorithms being developed in the Lados lab, it may be possible to schedule aircraft servicing only when needed, which could significantly reduce costs and out-of-service time.
"This technology, with its multiple uses, would bring important advancements to the materials and aircraft industries, contribute to increased safety and on-time performance, and undoubtedly save time and money for aircraft operators and, ultimately, the airlines," says Prof. Lados. "I think this research will go a long way to enhancing the way the aircraft industry views its inspection and monitoring systems."
www.wpi.edu
Worcester Polytechnic Institute, Mass., announces that a research team will conduct comprehensive testing and characterization studies to understand and monitor how stress and fatigue cause microscopic damage in metal components.
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Compact PlanarMet 300 grinder combines three grinding stages into one step
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Buehler, an ITW Company, Lake Bluff, Ill., introduces the PlanarMet 300, a new compact benchtop planar grinder built for fast and efficient grinding with high flatness and maximum edge retention. It features a fixed 305 mm (12 in.) grinding stone in conjunction with a high-performance 5.7 hp motor, and can accommodate ten specimens at time. It is easy to use with a self-calibrating auto-dressing system and easy stone change.
The PlanarMet 300 is designed to remove up to 0.6 mm of material per minute – up to ten times faster than grinding with SiC paper. The central-force specimen holder accommodates up to ten samples at a time and enables three to four grinding stages to be combined into a single step. The amount of material to be removed can be programmed accurately in increments of 0.1 mm.
For highly accurate material removal, the grinder offers either a timed-cycle or a controlled material depth mode, with adjustable powerhead speed and direction of rotation. Sample deformation is kept to a minimum by an integral cooling water inlet, combined with a unique water manifold, which ensures adequate cooling even under extremely aggressive grinding conditions.
The self-calibrating auto-dressing system with adjustable dressing frequency and depth provides a clean, flat grinding surface for each grinding cycle. Grinding stones (optionally Al2O3 or SiC) can be changed easily within minutes by unscrewing the center bolt, following which the system will auto-calibrate.
The grinder is designed for side-by-side use with EcoMet/AutoMet Grinder Polisher for direct specimen holder integration. It uses the same central force specimen holders as the EcoMet/AutoMet, and allows the user to complete additional preparation steps after planar grinding directly on the polishing system, without transferring to a new holder.
www.buehler.com
Buehler, an ITW Company, Lake Bluff, Ill., introduces the PlanarMet 300, a new compact benchtop planar grinder built for fast and efficient grinding with high flatness and maximum edge retention.
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