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Showing posts with label Metal science. Show all posts
Showing posts with label Metal science. Show all posts

Tuesday, December 6, 2011

Nano Paint Could Make Airplanes Invisible to Radar



A nanotube coating would allow a plane to absorb a radar beam, making it undetectable.
  • BY KATHERINE BOURZAC
A new nanostructured coating could be used to make paints for stealth aircraft that can't be seen at night and that are undetectable by radar at any time of day. The coating, made of carbon nanotubes, can be used to cloak an object in utter darkness, making it indistinguishable from the night sky.
Carbon nanotubes have many superlative properties, including excellent strength and electrical conductivity. They are also the blackest known material. The long straws of pure carbon, each just a few nanometers in diameter, absorb a broad spectrum of light—from radio waves through visible light through the ultraviolet—almost perfectly. Researchers are taking advantage of this perfect absorbance in highly sensitive imaging sensors and other prototype devices.
L. Jay Guo, professor of electrical engineering and computer science at the University of Michigan, realized it could be useful as a kind of camouflage. Stealth aircraft, he notes, are often painted black or dark blue to hide them from view.
Guo's group grew sparse forests of vertical carbon nanotubes on the surface of various three-dimensional objects, including a silicon wafer patterned with a tiny tank. The nanotubes make the objects appear wholly flat and black, and they disappear against a black background. The nanotube-coated things neither reflect nor scatter light.
This effect works, Guo says, because the nanotubes are perfectly absorbing and because when they are grown with some space between them, as in his experiments, their index of refraction is nearly identical to that of the surrounding air. This means that light won't scatter out of the nanotubes without being absorbed. The work is described in the journal Applied Physics Letters.
Guo says if an aeroplane painted with the nanotube coating were hit with a radar beam, nothing would bounce back and appear as if nothing were there.
"This type of cloaking is very interesting, especially since they have demonstrated operation in air," says Ray Baughman, director of the MacDiarmid NanoTech Institute at the University of Texas at Dallas. Baughman recently demonstrated that nanotubes can form an invisibility cloak when heated up underwater. The heat from a sheet of nanotubes affects the optical properties of the surrounding water, creating the illusion of invisibility.
Invisibility cloaks shield objects by manipulating incident light to simply flow around them. Materials that can achieve this must be made painstakingly and typically only work with a narrow spectrum of light—say, microwaves, or red or green light. Nanotubes are relatively easy to make and work across a broad spectrum.
However, it's not yet practical to grow forests of nanotubes on the surface of an aeroplane directly—growing such forests is a high-temperature, high-pressure process done in chambers much smaller than an aeroplane. But Guo says it should be possible to grow the nanotubes on the surface of tiny particles which can then be suspended in paint.

Monday, December 5, 2011

New way to test metal limits



SWINBURNE UNIVERSITY OF TECHNOLOGY   

DanNaylor_-_steel_pipe
“Our work helps a manufacturer design components and achieve the best results from the materials being used.”
Image: DanNaylor/iStockphoto
Before computer modelling there was only one way to discover the limits of a metal alloy, or any other material – test it to destruction. The problems with this approach are obvious: it’s expensive, wastes resources and takes time.

Therefore it’s not surprising that ‘virtual manufacturing’ at the Swinburne-based Australian Advanced Manufacturing Research Centre (AusAMRC) is attracting the attention of major industrial companies looking for solutions to complex technical issues.

Headed by Professor Jeong Yoon, the Swinburne virtual manufacturing team offers Australian manufacturers access to cutting-edge engineering and technology capabilities.

“What we do is simulate the manufacturing process using computer-aided engineering to predict
outcomes in the physical process,” Professor Yoon said. “Our work helps a manufacturer design components and achieve the best results from the materials being used.”

Companies using the computer simulation skills of Professor Yoon include Boeing – where the focus is on composite materials such as those used in the 787 Dreamliner ordered by Qantas – and aviation suppliers such as Sandvik Australia and Lovitt Technologies. 

“What we bring to a manufacturer is a combination of cost and time saving. If the behaviour of a material is not well known, it can take a long time to accurately assess its properties and the point at which it fails,” Professor Yoon saId.

“For example, in automotive design, a manufacturer must know how materials will perform in a crash. We can do most of the essential early analysis using our computer-modelling techniques.”

AusAMRC industrial liaison Miro Miletic says the work of Professor Yoon is attracting widespread interest in the manufacturing sector.

“Companies are beginning to appreciate what early stage computer-aided modelling can do for the predictability of their products, not just in terms of saving time and money, but in achieving a better finished product,” Mr Miletic said.
Editor's Note: Original news release can be found here.

Tuesday, October 11, 2011

New Metal Deposits Found at Rare Earth Mine


Heavy metalwork: A new separation facility is being built at Molycorp's mine in Mountain Pass, California. The company is spending $781 million to expand its refinery.
Molycorp Minerals

ENERGY

New Metal Deposits Found at Rare Earth Mine

The find could ease U.S. dependence on Chinese supply, but critics consider the announcement premature.

  • BY KRISTA ZALA
Molycorp Minerals announced last week that it had found significant ore deposits of heavy rare earth elements near its mine in Mountain Pass, California, and could start production in two years.
If it proves feasible, the discovery would put Molycorp at the forefront in breaking the United States' dependence on China's supply. However, speculation remains as to when, or if, the company can deliver.
"You can probably count on one hand the number of rare earth deposits where there are a predominant amount of heavies," says Jim Sims, Molycorp's vice president of corporate communications. "Finding terbium and dysprosium is a big deal. It will increase supply for most applications."
Rare earth metals are often all found together, typically with far more light than heavy elements. Both light and heavy elements go into making LCD screens, compact fluorescent bulbs, and the strong permanent magnets used in hybrid car batteries and wind turbines. Uses in hybrid car batteries and military equipment require adding heavier elements to keep the materials magnetized at their high operating temperatures.

Molycorp began extracting light rare earth metals from the open-pit Mountain Pass Mine in the 1950s. A costly cleanup, combined with low-cost competition from China, shut the mine down in 2002. China currently supplies at least 95 percent of the world's rare earth elements and up to 99 percent of the heavy varieties. The nation is cutting back exports amid growing demand to the point where some metals are fetching thousands of dollars a kilogram. Many western markets would welcome news of an alternative supply.
Other companies are surveying potential sites in Canada, Alaska, and Australia. Molycorp is the first such company to declare it has a viable source. Sims says measurements of the grade, mineral matrix, and size of the ore deposit appear favorable to commercial extraction. But it is relatively early in the process to go public with it.
"I'm highly skeptical of the real impact of the announcement this week," says Gareth Hatch, cofounding principal of Technology Metals Research, a firm that advises rare earth metals stakeholders. "We're being asked to take it on faith that it will happen, but it doesn't work like that."
The motivation may relate to the U.S. Department of Energy's December 2010 Critical Materials Strategy report, which expresses concern about a short-term supply disruption. The announcement asserting the discovery of four of the report's critical rare earth metals reassures manufacturers that the elements will be available to the supply chain at reasonable prices until other western suppliers start producing them in the next few years. Such a discovery also minimizes the need for engineers to redesign products so they won't require problematic components.
Molycorp appears to have faith in its light rare earths: it's spending $781 million to overhaul its equipment and expand potential production to 40,000 tons a year. But the 8-K statement filed with the U.S. Securities and Exchange Commission last week makes no promises as to what it will find once it starts drilling for the heavier varieties: "Molycorp must do extensive test drilling to determine the quantity and quality of the deposit. Accordingly, there can be no assurance as to the quantity or quality of such rare earth deposit or that such deposit will become proven or probable reserves."

Thursday, June 30, 2011

Platinum

Characteristics

Commodity
Platinum is considered as one of the most precious metals. In nature it is generally found as part of the so-called Platinum Group Metals (PGMs) and together with other metals such as gold, nickel or copper. The PGMs are Platinum (Pt), Palladium (Pd), Rhodium (Rh), Ruthenium (Ru), Iridium (Ir) and Osmium (Os). Platinum and Palladium are the most important of the PGMs.
Platinum is a rare, scarce and costly metal and it shows certain properties which make it unique. The specific chemical and physical properties of this metal are of essential use for many different applications. Platinum is known as the environmental metal. As a matter of fact, approximately 20% of the goods manufactured in the world contain platinum or are produced using platinum.

Origin and history
Although platinum is regarded as a "new" metal in its present form, it has a long history. Ancient Egyptians and Pre-Columbian Indian civilizations already valued it as a very important element. The "modern" discovery of platinum is attributed to Spanish conquerors in the 17th century. Actually the name platinum was given by the Spanish word, platina, meaning little silver. Spaniards had discovered alluvial deposits of the rare white metal when they were mining in search for gold in the Choco region in Colombia. Paradoxically, they considered platinum as a nuisance for their mining of gold.

After the introduction of platinum into Europe in the 18th century it became a metal of interest for scientists due to its special properties. In 1751, a Swedish assayer, Scheffer, recognized platinum as the seventh existing element at that time. The French physicist P.F. Chabaneau first obtained malleable platinum in 1789 in order to produce a chalice presented to Pius VI. It seems that the British chemist W. H. Wollaston was the first person to obtain a sample of pure platinum in the early 1800s. The techniques used by Wollaston in the separation of PGMs are considered to be the basis for modern platinum metallurgy.
The production of platinum requires very complex processing techniques that were not available until the end of the 19th century. Moreover, the high melting points of platinum made it very difficult to work with it. It was only with the development of new refining techniques that platinum was more widely used for new industrial applications. On the other hand, the use of platinum in fine jewelry rose quickly in the beginning of the 20th century. Platinum was already highly appreciated for its beauty and durability.
During World War II the availability of platinum was limited since it was declared as a strategic material. Use of platinum for most non-military applications was prohibited. After the war, consumption of platinum increased due to its catalytic properties. This increase in demand followed the development of molecular conversion techniques in the refining of petroleum. In the 1970s this demand grew even more thanks to the introduction of automotive emission standards in the developed countries.
One of the most important obstacles for a more widespread use of platinum in its history has been its limited supply. At present time, deposits of platinum are concentrated in a few areas in the world, mainly in South Africa and the Russian Federation. However, in the last few decades new mines have been opened and sophisticated platinum mining techniques have been developed. Platinum has become a metal of great importance in the world and prospects for this metal are very positive.

Description/Technical Characteristics
Platinum is one of the densest and heaviest metals, highly malleable, soft and ductile. It is extremely resistant to oxidation and to corrosion of high temperatures or chemical elements as well as a very good conductor of electricity and a powerful catalyzing agent. Platinum is soluble only in aqua regia. This precious metal has silvery-white color and does not tarnish.

Platinum 

Chemical symbol
Atomic number
Atomic weight
Crystal structure
Density
Melting point
Boiling point
Vickers hardness No (annealed condition)
Electrical resistivity
Thermal conductivity
Tensile strength
Electronic configuration
Isotopes




Quality
Platinum is considered as a native element even though it is never 100% pure platinum. When extracted, platinum is rather impure and it normally contains small quantities of other elements. Well-formed crystals of platinum are very rare and the frequent appearance of platinum is in nuggets and grains. Platinum most common source is from placer deposits. The usual variety of native platinum is polyxene. It is 80 to 90 per cent platinum, with 3 to 11 per cent iron, in addition to the other platinum group metals as well as gold, copper and nickel. Native platinum is the primary ore of platinum. However, platinum may also be obtained from the very rare native alloy platiniridium. Moreover, it may be found combined with arsenic as sperrylite mineral and with sulfur as cooperite mineral, being also associated with minerals as chromite and olivine.
In jewelry platinum is mainly processed to a grade of 95% as stamped in the different jewelry items through the Pt 950 hallmark. This degree of purity contrasts with the one of other precious metals like gold, which is normally between 33 and 75%



Uses
Platinum has multiple and essential applications while new uses for platinum are constantly developed.
Platinum demand by application in 2006
Source: UNCTAD based on data from Johnson Matthey's platinum
Jewelry

Platinum jewelry demand was forecast to account for roughly 25% of total platinum demand in 2006 (dowm from 50% in 2000). High and volatile prices have adversely affected purchases of platinum across the major regions, particularly China.
This precious metal is highly valued for its beauty and purity together with its particular properties. Although in Europe and USA the normal purity is 95%, in certain countries the purity may be down to 85%. Platinum colour, strength, hardness and resistance to tarnish are some of the advantages of this metal in jewelry. It provides a secure setting for diamonds and other gemstones, enhancing their brilliance. Moreover, its flexibility is an important element for jewelry designers. Platinum jewelry is regarded as the precious metal for the "New Millenium".
Platinum jewelry demand had been increasing steadily for two decades (1980-1999). The world's leading platinum jewelry market had for long been Japan, where platinum is very popular and fashionable. However, this market has been affected by the situation of the Japanese economy during the last few years. In the meantime platinum demand has grown sharply in China, which has overtaken Japan as the world's leading platinum jewerly market. The white metal has become highly appreciated and consumed in China. As a result, platinum-manufacturing capacity has been developed in China. Europe and North America are also quite dynamic markets for platinum, particularly in rings for the bridal sector.

Autocatalyst
Platinum, together with palladium and rhodium, are primary elements in autocalysts that control vehicle exhausts emissions of hydro-carbons, carbon monoxide, oxides of nitrogen and particulate. Autocatalysts convert most of these emissions into less harmful carbon dioxide, nitrogen and water vapor. Autocatalyst was forecast to account for almost 51% of total platinum demand in 2006 (up from 25% in 2000).
Demand for platinum in autocatalysts started to increase significantly in the seventies when clean air legislation was introduced in USA and Japan. Many other countries followed this policy since then. However, in the 1990s, there was a substitution from platinum to palladium in autocatalysts in the United States, mainly due to its relatively lower cost and better performance in autocatalysts. In Europe platinum was more widely used since it is an essential element for diesel cars. Recent developments in the palladium market together with technological advances have led to a switch back to platinum. In recent years demand for platinum in autocatalysts has shown a considerable growth in emerging countries that introduced new environmental legislation. Demand for platinum in this application is expected to grow as stricter emissions standards and regulations are approved.
Electrical and electronics
Platinum is used in the production of hard disk drive coatings and fiber optic cables. The increasing number of personal computers will have a positive effect on platinum demand in the future. Other applications include thermocouples that measure temperature in the glass, steel and semiconductor industries or infra-red detectors for military and commercial applications. It is also used in multi-layer ceramic capacitors and crucibles to grow single crystals

 Platinum RTD 




platinum canopy caps

PLATINUM IPHONE MONTAGE_.jpg

Chemical
Platinum is used in fertilizers and explosives as a gauze for the catalytic conversion of ammonia to nitric acid. It is also used in the fabrication of silicones for the aerospace, automotive and construction sector. In the fuel sector it is important as a petrol additive to enhance combustion and reduce engine emissions. Moreover, it is a catalyst in the production of biodegradable elements for household detergents.
Glass
Platinum is used in glassmaking equipment. It is used in the manufacturing of fiberglass reinforced plastic and of glass for liquid crystal displays (LCD). In this context, some new developments in the production of LCD glass and cathode ray tubes, both used in computer screens should be mentioned.

Reinforcement glass fibre

The largest amount of platinum in use in the glass industry is for the production of textile glass fibre, commonly referred to as reinforcement fibre as it is mainly used for strengthening other materials. Its widest application is in glass-reinforced plastics (grp). Glass fibre producers use platinum components to channel the molten glass, but the main use of platinum and rhodium is in the fiberisation process itself. Fiberisation is the drawing of the glass fibres from a platinum alloy container called a "bushing" – a rectangular open topped box, the base of which has many precisely shaped holes, or jets, through which the fibres are drawn.

Liquid crystal displays (LCD)

LCD glass, used in applications such as digital watches and laptop computers, is the most intensive user of platinum and rhodium per unit of glass produced. This is due to the harsh conditions under which the raw materials for the glass are melted (usually at 1650oC) and the quality of glass required, which can be as little as half a millimetre thick and demands zero defects.

Cathode ray tube (CRT) displays

CRT displays refer to the monitors commonly used as TVs and visual display units (VDUs) for computers. There are two parts to the glass needed to make the CRT display - the cone glass panel that forms the back of the monitor, and the screen glass panel at the front. Platinum-rhodium alloys are used mainly in the production of the screen glass.

Optical & ophthalmic glass

In order to produce high quality optical glass, platinum equipment is used in the key areas of melting, conditioning and forming. Pure platinum is the preferred material since the use of alloys containing rhodium and, to a lesser extent, iridium, leads to unwanted colouration of the glass.

Container glass

Container glass refers to non-crystal tableware as well as bottles for drinks, jars for foodstuffs and containers for perfume and other items. The extent to which platinum is used mainly depends on the properties of the glass, which vary considerably according to its composition. Generally, the more corrosive the glass, the more platinum is required.

Ceramic glass

Commonly used in applications such as the flat glass surface of electric cooker hobs, ceramic glass has grown in demand in recent years. Large quantities of pgm equipment are used in the production of this type of glass.


Investment
Platinum is seen as an attractive investment vehicle and as a good way of hedging assets against inflation. This attraction for platinum investment is spreading worldwide and is based on platinum relative scarcity, its historical price performance and unique fundamentals. Investing in platinum may be done in futures and options or in bars, ingots and bullion coins like the American Eagle, the Australian Koala or the Canadian Maple Leaf among others.
Petroleum
Platinum is used as a refining catalyst in the petroleum industry.

Medical
Platinum is used in anti-cancer drugs and in implants. It is also used neurosurgical apparatus and in alloys for dental restorations.

 Applicationsinclude medical



Spark plugs
Most vehicles in North America use platinum-tipped spark plugs. In Europe higher durability requirements have led to an increase in the amount of platinum used in spark plugs.
Fuel cells
Fuel cells are devices that generate electric power. They are being developed as an alternative to internal combustion engines in vehicles. Most fuel cells apply proton exchange membrane technology producing energy from hydrogen and oxygen by using platinum catalysts. The use of fuel cells brings about environmental and economic advantages. They are more energy efficient and produce negligible pollution. All the major automotive companies, lead by Daimler-Chrysler, are planning to have fuel cell powered light vehicles by 2003-2004. Actually, there are already some fuel cell heavy vehicles working. However, the doubt remains since every vehicle using a fuel cell will be one that will not use a conventional autocatalyst. The effect on platinum demand will depend on which device uses more platinum. Present research is focusing on improving performance and reducing costs of fuel cells. Fuel cells can also provide stationary power generation. The use of platinum in fuel cells seems to be one of the platinum applications with best prospects for future demand.

Medical

Platinum anti-cancer drugs

Platinum has the ability, in certain chemical forms, to inhibit the division of living cells. The discovery of this property in 1962 led to the development of platinum-based drugs to treat a wide range of cancers. Cisplatin, the first platinum anti-cancer drug, began to be used in treatment in 1977. Testicular cancer was found to be susceptible to treatment with cisplatin and there were other successes with ovarian, head and neck cancers.
Researchers at the Institute of Cancer Research and the Royal Marsden Hospital in London achieved a significant step when they found a compound similar to cisplatin in terms of activity, but much less toxic. This drug, carboplatin, was first approved in 1986. Recent research has sought to identify new platinum compounds which will treat tumours which do not respond to or which become resistant to cisplatin and carboplatin. The first of these drugs to reach commercialization is oxaliplatin, which is being marketed under the trade name Eloxatin.
Upcoming platinum anti-cancer drugs include satraplatin, which is being developed for treatment of prostate cancer. It is claimed that the use of satraplatin results in a higher survival rate than with existing chemotherapy treatments. Satraplatin will also be the first platinum anti-cancer drug that can be administered orally instead of intravenously, allowing patients to be treated at home. The drug is currently undergoing clinical trials.

Platinum biomedical components

Platinum can be fabricated into very tiny, complex components. As it is inert, platinum does not corrode inside the body, while allergic reactions to platinum are extremely rare. Platinum also has good electrical conductivity, which makes it an ideal electrode material.
Pacemakers, used to treat heart disorders which result in slow or irregular heartbeat, usually contain at least two platinum-iridium electrodes, through which pulses of electricity are transmitted to stabilise the heartbeat. Platinum electrodes are also found in pacemaker-like devices which are used to help people at risk of fatal disturbances in the heart's rhythm. This risk can be minimised by implanting a device known as an Internal Cardioverter Defibrillator (ICD) which sends a massive electric charge to the heart as soon as it detects a problem.
Catheters, flexible tubes which can be introduced into the arteries, are widely used in modern, minimally-invasive treatments for heart disease. Many catheters contain platinum marker bands and guide wires, which are used to help the surgeon guide the device to the treatment site. The radio-opacity of platinum, which makes it visible in x-ray images, enables doctors to monitor the position of the catheter during treatment.

Platinum Use in Medical Devices Highlighted in April's PMR
The most recent edition of the Platinum Metals Review, PMR, features a
comprehensive review of the biomedical applications which incorporate
platinum as an integral part of devices and active pharmaceutical
ingredients used to sustain and enhance quality of life.
London, UK…The April edition of the Platinum Metals Review (PMR), the platinum industry's
leading technical journal, has published a comprehensive review of those biomedical applications

which depend upon platinum and its alloys to sustain and improve the quality of life.  The article
entitled A Healthy Future:  Platinum in Medical Applications, appears in the Platinum Metals
Review, Volume 55 Issue 2, April 2011, Pgs 98 - 107.
Despite the perception of high cost, the unique chemical, mechanical and electrical properties of
platinum have been recognized by leading medical device companies as an enabling technology
in developing next generational device with increased longevity and durability.  Because of the
metal's radiopacity, conductivity and inertness, platinum has been incorporated as an integral part
of a range of specialized devices including pacemakers, defibrillators, stents and neurostimulation
devices.
Platinum has become a reliable tool in the arsenal of medical device companies who are striving
to satisfy the growing demand for advanced medical technologies as the global population
expands and ages in both the developed and emerging economies

Industrial Applications Of Platinum

  • Nitric Acid - Platinum-based catalysts have now been used in the commercial manufacture of nitric acid for a century.
  • Silicones - Adding platinum compounds controls curing, helping to achieve the properties required for the numerous uses they have in everyday life.
  • Computer Hard Disks - Platinum improves the data storage capacity of hard disks and today, all hard disks contain platinum in their magnetic layers.
  • Electronic Components - Palladium-containing components are used in virtually every type of electronic device.
  • Crucibles - With their high melting points and resistance to chemical attack, iridium and Platinum are the preferred material of choice for crucibles.
  • Glass - Used in the production of glass, platinum's high melting point, strength and resistance to corrosion allow it to withstand the abrasive action of molten glass.
  • Medical - Platinum inhibits the division of living cells and this property has resulted in the development of platinum-based drugs to treat a wide range of cancers.
  • Sensors - Are used in a variety of applications: measuring of oxygen and NOx levels in car engine control systems; detection of carbon monoxide in home safety devices; wire, foil and disc electrodes for various sensors in medical equipment



Monday, May 2, 2011

ARTICLE - ALUMINUM POISONING

ARTICLE - ALUMINUM POISONING





As the metal aluminum is present in our food, water supply, and soil, most people suffer from some degree of aluminum toxicity. After years of accumulated exposure and storage of it in body tissues, this poison can have results ranging from brain degeneration to skeletal deformities.

Dangers of Aluminum Toxicity

Sources of Aluminum

Nutritional Support

While the first step in ridding your body of this poison is to avoid aluminum intake as much as possible. The next is to provide your body with nutritional support to give it the strength it needs to detoxify this metal. There are several supplements that can assist in this process. They are Core Level C, Core Level Health Reserve and Core Level Liver.

Detoxification Symptoms

When aluminum comes out of its stored locations in your body it can act as an irritant. For example it has a tendency to irritate nerve endings which can irritate muscles. Therefore, when someone is detoxifying aluminum, there can be discomfort involved. And, since the kidneys are the organs that handle this detoxification, there may be pain in the back, over the kidneys, also.
Because aluminum tends to concentrate itself in the brain, the detoxification process can be accompanied by mental confusion.
It can also cause flu-like symptoms with fever, chills and mucous discharge. The detoxification will run its course and the symptoms will go away. Because any nasal discharge will be toxic, spit it out instead of swallowing it.

Reducing Aluminum Exposure

Over to You

While your body can tolerate low levels of aluminum, you must be sure that the level stays low and does not build up. This requires care and continued monitoring. There are tests such as hair/urine/blood analysis that can be done to help you monitor the aluminum levels in your system. Let us know if you need any assistance in getting these done.
 Sanjana