Slippery customer: A greener antiwear additive for engine oilsJuly 24, 2008Titanium, a protean element with applications from pigments to aerospace alloys, could get a new role as an environmentally friendly additive for automotive oil, thanks to work by materials scientists from Afton Chemical Corporation (Richmond, Va.) and the National Institute of Standards and Technology (NIST). In a recent paper,* the researchers established that a titanium compound added to engine oil creates a wear-resistant nanoscale layer bound to the surface of vulnerable engine parts, making it a credible substitute for older compounds that do not coexist well with antipollution equipment. Modern engine lubricating oil is a complex, highly engineered mixture, up to 20 percent of which may be special additives to enhance properties such as viscosity and stability and to reduce sludge formation and engine wear, according to Afton specialists. For years antiwear additives for high-performance oils have been phosphorous compounds, particularly ZDDP,** that work by forming a polyphosphate film on engine parts that reduces wear. Unfortunately phosphorus is a chemical poison for automobile catalytic converters, reducing their effectiveness and life span, so industry chemists have been searching for ways to replace or reduce the use of ZDDP. It's not a simple problem because the additive has several useful functions in addition to wear resistance. Titanium is one candidate replacement. Mechanical tests of an organic titanium compound at Afton demonstrated that it provided superior wear resistance when added to a fully formulated engine oil, suggesting that oil chemists could use less ZDDP. Just how the titanium compound works was an open question, however. Surface analysis tests could detect titanium in the wear tracks of test surfaces but not with enough sensitivity to determine its chemical nature-and whether, for example, it was just lying there or bound to the metal surface. To resolve the issue, the researchers turned to NIST's soft X-ray beamline at the National Synchrotron Light Source (NSLS) in Brookhaven, N.Y. The NIST beamline instruments use low-energy ("soft") X-rays that can be precisely tuned to specific elements to measure chemical bonds both at the surface of a sample and deeper into the bulk of the material. Powered by the NSLS, the facility is at least 10 times more sensitive than commonly available instruments. The measurements revealed that the antiwear enhancement comes from titanium chemically bound into the metal structure of the engine surface, forming a hard oxide, iron titanate. Comparing the test data to that of several possible compounds, the research team was able to identify the specific oxide. While considerably more work remains to be done, the results suggest that titanium could play an important role in future low-phosphorus lubricating oils. National Institute of Standards and Technology (NIST) |
|||||||||||||||||||||
| Related Titanium Current Events and Titanium News Articles Large-scale cousin of elusive 'magnetic monopoles' found at NIST Any child can tell you that a magnet has a "north" and a "south" pole, and that if you break it into two pieces, you invariably get two smaller magnets with two poles of their own. But scientists have spent the better part of the last eight decades trying to find, in essence, a magnet with only one pole. Where surgery was the standard, casting may be the future When parents are told their babies' scoliosis needs treatment, they often try bracing first. If that fails, they need surgery to place metal rods in their backs with spinal fusion later on. These children face the risk of complications from the surgery and their backs and chests may be stiff for life. Laser processes promise better artificial joints, arterial stents Researchers are developing technologies that use lasers to create arterial stents and longer-lasting medical implants that could be manufactured 10 times faster and also less expensively than is now possible. Toward a nanomedicine for brain cancer In an advance toward better treatments for the most serious form of brain cancer, scientists in Illinois are reporting development of the first nanoparticles that seek out and destroy brain cancer cells without damaging nearby healthy cells. New robot travels across the seafloor to monitor the impact of climate change on deep-sea ecosystems Like the robotic rovers Spirit and Opportunity, which wheeled tirelessly across the dusty surface of Mars, a new robot spent most of July traveling across the muddy ocean bottom, about 40 kilometers (25 miles) off the California coast. Building better bone replacements with bacteria Bacteria that manufacture hydroxyapatite (HA) could be used to make stronger, more durable bone implants. Professor Lynne Macaskie from the University of Birmingham this week (7-10 September) presented work to the Society for General Microbiology's meeting at Heriot-Watt University, Edinburgh. Safety of combat military vehicles examined A Queen's University Belfast academic is working on research that could help protect the lives of military based in Afghanistan. Nanotech particles affect brain development in mice Maternal exposure to nanoparticles of titanium dioxide (TiO2) affects the expression of genes related to the central nervous system in developing mice. Astrophysicists Solve Mystery in Milky Way Galaxy A team of astrophysicists has solved a mystery that led some scientists to speculate that the distribution of certain gamma rays in our Milky Way galaxy was evidence of a form of undetectable "dark matter" believed to make up much of the mass of the universe. New way to fix leaking mitral heart valves safe in initial testing A new nonsurgical technique to repair leaking mitral valves in heart failure patients was safe in a study reported in Circulation: Cardiovascular Interventions. More Titanium Current Events and Titanium News Articles |
|||||||||||||||||||||
|
|||||||||||||||||||||
|
|||||||||||||||||||||