systems, strategies & research for lubrication professionals an publication | february ... ·...
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SYSTEMS, STRATEGIES & RESEARCH FOR LUBRICATION PROFESSIONALS AN PUBLICATION | FEBRUARY 2014
Digital TLT: Sponsored this month by Afton Chemical Corp. at www.stle.org.
10 YEARS of publishing excellence
TLTT R I B O L O G Y & L U B R I C A T I O N T E C H N O L O G Y
Automotive Tribology New column from Dr. Ed Becker
Beware of Conventional Wisdom It can save or doom a people
Q&A with Dr. Michael Khonsari Developing a unified model of friction
A look at milestones Why first isn’t always best
TOMORROW’S TRIBOLOGY10 trends that will change the future of lubrication
PEER-REVIEWED PAPER (EDITOR’S CHOICE)
36 Selection of Low Ozone Depleting Oxygen System Cleaning Solvents
Marcie B. Roberts, Lois J. Gschwender and Carl E. Snyder, Jr.
FEATURES
TLT / FEBRUARY 2014 / VOLUME 70 / NO. 2
242016
Contents
COMMENTARY
24 Beware of conventional wisdom
It can save or doom a people.
By Dr. Robert M. Gresham
FEATURE ARTICLE
26 10 trends shaping tomorrow’s tribology
Selecting the right mix of equipment and tests are key factors to a successful oil analysis program.
By Jeanna Van Rensselar
20 MINUTES WITH…
16 Dr. Michael Khonsari
This well-known tribology researcher and professor at Louisiana State University discusses the future development of a comprehensive and unified model of friction and wear.
By Karl M. Phipps
STUDENT POSTER ABSTRACTS
20 Relating the Structure of Articular Cartilage to Function
By Axel Moore and David L. Burris
Extended abstracts written by winners of the Student Poster Competition held at STLE’s 2013 Annual Meeting & Exhibition.
10
YE A R A N N I V E
R SARY
2003 - 2013
TLT
26
W W W . S T L E . O R G T R I B O L O G Y & L U B R I C A T I O N T E C H N O L O G Y F E B R U A R Y 2 0 1 4 • 1
DEPARTMENTS
10 Tech Beat
Corrosion-proof nickel titanium bearings; staggered wind turbines; aqueous aluminum nanoclusters.
By Dr. Neil Canter
44 Newsmakers
This month’s newsmakers include Timken, Croda, CSM Instruments and Hydrotex.
48 New Products
Pro-Mix lubricating systems; renewable synthetic lubricant basestocks; bench-top instrument; process cleaners; and biodegradable open gear lubricant.
50 Sounding Board
How will oil analysis change five years from now?
57 Advertisers Index
58 Resources
Keep up to date with the latest technical literature available in print and online.
PUBLISHER/EDITOR-IN-CHIEF Thomas T. Astrene
MANAGING EDITOR Karl M. Phipps
CONTRIBUTING EDITORS Dr. Neil Canter
Dr. Robert M. Gresham Jeanna Van Rensselar
CIRCULATION COORDINATORS Myrna Scott Judy Enblom
DESIGN/PRODUCTION Joe Ruck
ADVERTISING SALES Tracy Nicholas VanEe
Phone: (630) 922-3459 Fax: (630) 904-4563 [email protected]
Chris Napoleon Napoleon Engineering Services Olean, New York
Dr. Martin Greaves The Dow Chemical Co. Freeport, Texas
Dr. Patrick Henning Spectro, Inc. Chelmsford, Massachusetts
Dr. Anoop Kumar Royal Manufacturing Co. Tulsa, Oklahoma
Matt Mapus Sea-Land Chemical Co. Westlake, Ohio
Mike Mayers Analysts, Inc. Stafford, Texas
Paul Michael Milwaukee School of Engineering Milwaukee, Wisconsin
Dr. Steve Shaffer Bruker Nanoservices Tribology and Mechanical Testing (TMT) Campbell, California
Dr. Rajesh Shah Koehler Instrument Bohemia, New York
TRIBOLOGY AND LUBRICATION TECHNOLOGY (USPS 865740) Vol. 70, Number 2, (ISSN-1545-858), is published monthly by the Society of Tribologists and Lubrication Engineers, 840 Busse Hwy, Park Ridge, IL 60068-2376. Periodicals Postage is Paid at Park Ridge, IL and at additional mailing offices. POSTMASTER: Send address changes to Tribology and Lubrication Technology, 840 Busse Hwy, Park Ridge, IL 60068-2376.
EDITOR Evan Zabawski
Calgary, Alberta, Canada
TECHNICAL EDITORS
Contents
4 President’s Report STLE Tribology Frontiers
Conference
6 From the Editor Milestone Firsts
8 Headquarters Report How can we help you?
60 Social Media Marketing So what’s your story?
62 Automotive Tribology The road to better mileage
64 Cutting Edge Remembering Sanjay Biswas
and Brian Briscoe
COLUMNS
60 62
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2 • F E B R U A R Y 2 0 1 4 T R I B O L O G Y & L U B R I C A T I O N T E C H N O L O G Y W W W . S T L E . O R G
ALUMINUM IS CONTINUING TO be an im-portant metal used in the manufacture of automobiles. Its lighter weight (as compared to steel alloys), good strength and ability to elongate are im-portant factors that enable automo-biles to be produced with higher levels of fuel economy.
But aluminum does not have the mechanical strength of steel. In a previ-ous TLT article, a new process known as high-pressure torsion was discussed that increases the strength of alumi-num to a level comparable to carbon
steel without sacrificing ductility.1 A well-known alloy, 7075 aluminum, was solution treated at 480 C for five hours followed by quenching in room-temperature water. The resulting metal was found to display a strength of 1.0 GPa in a tensile strength test, which is comparable to a typical hardened and tempered carbon-steel alloy.
Aluminum is fabricated into com-ponents used in automobiles through a series of metalworking operations that occur mainly with water-based fluids. There are a number of challeng-es in finding optimum machining con-ditions for specific aluminum alloys.
But one of the intriguing issues is what happens to the aluminum alloy when it comes into contact with water, which is the primary component in a water-based metalworking fluid. Alu-minum can readily form a series of metal salts with other additives used in MWFs such as fatty acids. These salts can become water insoluble and form residues that are similar to greases. Such contaminants are undesirable be-cause they can degrade the perfor-mance of the MWF.
Chong Fang, assistant professor of chemistry at Oregon State University in Corvallis, Ore., says, “Addition of aluminum to water leads to the forma-tion of a variety of complex species that include monomeric, oligomeric and polymeric hydroxides. These spe-cies are present in water as colloidal solutions and gels, but they can also form precipitates and crystals.”
Gaining a better understanding of the composition of these species is ex-tremely difficult. Fang says, “Many of these species cannot be readily identi-fied because they are difficult to detect
using techniques such as 27Al nuclear magnetic resonance (NMR) and con-ventional Raman spectroscopy. The problem is water binds in many differ-ent positions with respect to alumi-num, leading to the formation of dif-ferent types of highly coordinated structures, and there may be transient species involved. The elucidation of aqueous aluminum speciation path-ways demands a technique capable of monitoring molecular choreography.”
Some of these aluminum water species are known as hydroxide clus-ters that contain multiple aluminum atoms. Fang says, “Formation of alu-minum clusters is dependent on fac-tors such as reagent concentration and the method and rate of solution pH change.”
If specific aluminum clusters can be selectively synthesized, then these clusters can be studied to gain an un-derstanding of their respective proper-ties and how they may form when wa-ter contacts aluminum metal. One specific “flat” aluminum cluster has now been synthesized through a pH-controlled process monitored by a novel analytical technique.
FEMTOSECOND RAMANSPECTROSCOPYFang and his fellow researchers syn-thesized an aqueous aluminum nano-cluster known as Al
13 by slowly rais-
ing the pH of a solution and following the reaction using an emerging tech-nique known as Femtosecond Stimu-lated Raman Spectroscopy (FSRS). He says, “We chose to produce Al
13 be-
cause this species represents a natu-rally occurring mineral that is octahe-dral in configuration. We have also
TECH BEAT
Aqueous aluminum nanoclustersA new analytical technique monitors the synthesis of a flat aluminum nanocluster.
1 4 • F E B R U A R Y 2 0 1 4 T R I B O L O G Y & L U B R I C A T I O N T E C H N O L O G Y W W W . S T L E . O R G
pioneered a novel technique that enables thin metal-ox-ide films that are a few atomic layers thick to be prepared directly from solu-tion instead of using more expensive methods. This in-tegrated platform will en-able Al
13 potentially to be
used as a green solution in broad applications such as transistors, solar energy cells, catalytic converters and corrosion inhibitors.”
The researchers used an electrochemical process to slowly and precisely raise the pH of the reaction mix-ture to produce Al
13. Fang
says, “In Stage I, we started at a pH of 2.2 where the dominant aluminum species prepared from a 1 molar alu-minum nitrate solution is the monomeric aluminum hexa-aqua ion.”
The solution is placed in a two-compartment electro-chemical cell, which contains an anode compartment and a cathode compartment. Ni-trate ions migrate into the an-ode compartment where oxygen is pro-duced. Aluminum ions migrate into the cathode compartment where hydrogen is produced. The charge balance is maintained. An electric current is used to control the process, which exhibits a net reduction in proton (hydrogen ions) concentration in the cathode compartment as the pH is slowly in-creased, wherein condensation of alu-minum species occurs to produce larger aluminum nanoclusters.
FSRS was used to follow the reac-tion because of the limitation of con-ventional Raman spectroscopy. Fang says, “We needed to detect small changes in Raman vibrational modes down to between 300 and 500 cm-1.Unfortunately, this frequency is too close to the fundamental pulse. In-stead, we used non-resonant (800 nanometer) FSRS spectroscopy with a newly developed Raman probe pulse
based on our photonic advances to cover that spectral range.”
FSRS reveals that the reaction moves to stage II at a pH between 2.4 and 2.7 due to the formation of an in-termediate identified as Al
7. Fang says,
“As the pH increases to between 2.7 and 3.2, further deprotonation strips positive charges at the outer shell of Al
7, leading to the formation of the
larger Al13
cluster, which represents Stage III of the process. The key is to catch a glimpse of aluminum specia-tion as the chemistry proceeds in wa-ter.”
Figure 3 shows the two-compart-ment electrochemical cell and the re-action process as it moves from mono-meric aluminum in Stage I to Al
13
Stage III via an octahedrally coordi-nated Al
7 intermediate in Stage II.
The researchers deliberately ran this reaction sequence at a low pH be-
cause the involving alumi-num clusters could be iden-tified using FSRS aided by computations, and they rep-resent the onset of larger alu-minum cluster formation. Fang says, “Work is under-way to characterize the dif-ferent types of clusters and species that form in aqueous solution at pH values above 7. This effort might also bring us closer to the regime where dehydration and an-nealing yield metal oxide thin films with versatility.”
This work is also of inter-est to formulators of MWFs because they are designed to operate at a pH of 9. Poten-tially, the aluminum clusters identified at this alkaline pH may help formulators better understand how to prepare products that will minimize such concerns as staining.
Additional information can be found in a recent ar-ticle2 or by contacting Dr. Fang at [email protected].
REFERENCES
1. Canter, N. (2011), “Super-Strong, Ductile Aluminum,” TLT, 67 (1), pp. 10-11.
2. Wang, W., Liu, W., Chang, I., Wills, L., Zakharov, L., Boettcher, S., Cheong, P., Fang, C. and Keszler, D. (2013), “Electrolytic Synthesis of Aqueous Aluminum Nanoclusters and In Situ Charac-terization by Femtosecond Raman Spectroscopy and Computations,” Proc. Natl. Acad. Sci. U.S.A. 110(46), pp. 18397-18401.
Neil Canter heads his own
consulting company, Chemical
Solutions, in Willow Grove, Pa.
Ideas for Tech Beat can be
submitted to him at
Figure 3 | A study using a new technique known as Femto-second Stimulated Raman Spectroscopy has enabled re-searchers to produce an aqueous aluminum nanocluster known as Al
13, and holds the promise for identifying other
aluminum species present in water in the future. (Courtesy of Oregon State University)
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