Kutz M. Handbook of materials selection
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464 SOURCES OF MATERIALS DATA
The majority of all databases in existence in any form (see Section 6) are
textual in nature, even many of those purporting to be property databases.
Searchers of such textual property databases are searching based upon strings
of alphanumeric characters reflecting their interest, not on numeric values of the
properties except as they are expressed as strings. This is quite different from
the case for numeric property databases, as we shall see in the next section.
3.2 Numeric Databases
Databases classed as numeric (a) have data stored in them in numeric format
and (b) are searched numerically. For example, numeric databases may be
searched for all materials having a specific property equal to or greater than a
certain value or within a certain specific range; this would not be possible in a
textual database. To provide such searchability, almost all numeric databases are
electronic in nature (see Section 4) though many hardcopy publications also
contain extensive amounts of numeric data.
To accommodate numeric searching, the properties must be entered into a
database digitally as numbers not simply as alphanumeric strings. And to be
useful to material specialists and designers, they must have meaningful precision
(i.e., numbers of significant figures) and units associated with each number. The
numeric number of a property is of no value if it does not have the applicable
unit(s) associated with it.
3.3 Metadata
The concept of metadata as ‘‘data about data’’ was introduced earlier, and it is
appropriate at this stage to describe the concept and its importance in greater
detail.
9
It is vital, especially for numeric databases and independent of their
platform, to have ample background information on the numeric properties in-
cluded in the database and closely associated with the individual properties.
Examples of metadata include:
●
Original source of data (e.g., from tests at ABC laboratories)
●
Test methods by which data were obtained (e.g., ASTM methods, size
and type of specimen)
●
Production history of the samples for which the data are applicable (e.g.,
annealed, heat treated, cold worked, special handling?)
●
Exposure experienced by the samples tested, if any, prior to the test (e.g.,
held 1000 h at 500
⬚F)
●
Conditions under which the properties were determined (e.g., tested at
300
⬚F, 50% humidity)
●
Number of individual tests represented by and statistical precision of the
values presented (e.g., individual test results; averages of x number of
tests, statistical basis)
●
Any subsequent evaluation or certification of the data by experts (e.g.,
ASME Boiler & Pressure Vessel Committee)
It should be clear that the value of information in any database, but especially
in a numeric database, is greatly diminished by the absence of at least some and
5 DATA QUALITY AND RELIABILITY 465
potentially all of these types of metadata. For example, a listing of the properties
of an alloy is of no value at all if it is not clear at what temperature they were
determined. It should be clear that metadata are an integral part of every material
property database. Similar properties of a material are of virtually no value if it
is not clear how they were mechanically and thermally processed before they
were tested.
4 SUBJECTS OF DATA SOURCES
It is next useful to note some of the major categories of data available and
illustrate the manner in which they are likely to be classified or structured. From
this point on, the discussion will focus primarily upon numeric materials prop-
erty data of interest to the engineer and scientist.
The total breadth of properties and characteristics may reasonably be illus-
trated by the following four categories:
●
Fundamental (atomic level) properties
●
Physical properties (atomic and macro/alloy levels)
●
Mechanical properties (macro/alloy level)
●
Application performance (macro/alloy or component levels)
To provide greater detail on the first three categories, it is helpful to utilize
the taxonomy of materials information developed by Westbrook
1
and illustrated
in Fig. 1. While the entire list of potential uses of data described above is not
included, the taxonomy in Fig. 1 illustrates the variety of subject matter quite
well.
The fourth major category identified above involves what is referred to as
application performance but which in itself incorporates several individual areas:
●
Fabrication characteristics (sometimes called the ‘‘ilities’’)
(a) Fabricability (‘‘workability’’)
(b) Forming characteristics (‘‘formability’’)
(c) Joining characteristics (‘‘joinability’’)
(d) Finishing characteristics (‘‘finishability’’)
●
Service experience
(a) Exposure conditions
(b) Service history
(c) Failures observed and their causes
It is not necessary to discuss these categories individually, simply to recognize
that specific databases may well focus on only one or a few of these subjects
and that rarely if ever would all subjects be included in any one database.
5 DATA QUALITY AND RELIABILITY
It was noted in Section 2 that individuals doing preliminary material selection
or screening may have different needs with regard to quality and reliability than
those doing design functions. It is appropriate at this stage to review the major
466 SOURCES OF MATERIALS DATA
Fig. 1 Taxanomy of materials information. From ASM Handbook, Vol. 20: Materials Selection
and Design (1997), ASM International, Materials Park, OH 44073-0002, fig. 1, page 491.
factors that go into judgments of data quality and reliability.
10
There are two
parts to such a discussion: (1) the two major factors affecting the data themselves
and (2) the degree to which those factors are reflected in database content.
The two factors affecting quality and reliability include (a) the manner in
which the data were obtained and (b) the statistical reliability of the data pre-
sented.
First and foremost, the users of a database for whatever purpose will want to
know that consistent standards were applied in assembling the data for that
database, and that the properties of one material may reliably be compared with
those for another. They would also prefer that those properties have been gen-
erated by well-known standard methods such as those prescribed by organiza-
tions such as ASTM and ISO.
4
They may also be quite interested in knowing
6 PLATFORMS: TYPES OF DATA SOURCES 467
the specific source of the original data; realistically some laboratories [e.g., the
National Institute of Standards and Technology (NIST)] have a more widely
recognized reputation than others.
The second major factor affecting how the user applies information from a
specific database is the statistical reliability of the values included therein. The
user will be interested in which of the following categories best describes the
values presented:
●
Raw data (the results of individual tests)
●
Average of multiple tests (how many tests represented?)
●
Statistically analyzed (at what statistical definition and with what confi-
dence?)
●
Evaluated/certified (by whom? for what purpose?)
Of equal importance to the user of any database for whatever reason is the
degree to which those factors affecting quality and reliability as noted above are
presented in the database itself and, therefore, are fully understood by the user.
In some instances there may be one or several screens of background information
laying out the general guidelines upon which the database was generated. This
is particularly effective if the entire database represents properties of a common
lineage and character. On the other hand, if the user fails to consult this upfront
information, some important delimiters may be missed and the data misinter-
preted.
Another means of presenting the metadata concerning quality and reliability
is within the database itself. This is especially true for such factors as time–
temperature parameters that delimit the applicability of the data and units and
other elements of information that may restrict its application (see Section 3.3).
It is also especially important in instances where the individual values may
vary with respect to their statistical reliability. While the later case may seem
unlikely, it is actually quite common, as when ‘‘design’’ data are presented: in
such cases, the strength values are likely to be statistical minimum values while
moduli of elasticity and physical properties are likely to be average values, and
the difference should be made clear in the database.
6 PLATFORMS: TYPES OF DATA SOURCES
The last feature we will consider before identifying specific data sources is the
variety of platforms available for databases today. While it is not necessary to
discuss them in detail, it will be obvious that the following choices exist:
●
Hardcopy (published books, monographs, etc.)
●
Self-contained electronic (floppies, CDs, etc.)
●
Internet sites (available online; perhaps downloadable)
The only amplification needed on these obvious options is that the last one,
the Internet, has become an interesting resource from which to identify and
locate specific sources of materials data, and that trend will likely continue to
increase. Two large caveats go with the use of Internet sources however: (1) a
468 SOURCES OF MATERIALS DATA
great deal of ‘‘junk’’ (i.e., unreliable, undocumented data) may be found on
Internet web sites, and (2) even those containing more reliable data seldom meet
all users needs with respect to covering the metadata. It is vital that the users
themselves apply the guidelines listed earlier to judge the quality and reliability
of sources located on the Internet.
7 SPECIFIC DATA SOURCES
It is beyond the scope of this chapter to provide an exhaustive list of data sources
because there are thousands of them of varying presentation platforms, styles,
and content. What we will do here is highlight a few of the potentially most
useful sources, in the sense that their coverage is relatively broad and/or they
represent good places to go to look for new and emerging sources of materials
data.
The categories discussed below will include:
●
ASM International, a technical society for materials engineers and spe-
cialists that produce and provide a wide range of materials databases in
hardcopy and electronic form (see Section 7.1)
●
STN International, a service of the American Chemical Society, also pro-
viding (for fee) access to a very wide range of numeric databases as well
as a great many textual/bibliographic databases on materials-related sub-
jects (see Section 7.2).
●
The Internet, the most rapidly expanding source for materials data in a
variety of forms (see Section 7.3).
For readers interested in more extensive listings, reference is made to the
article ‘‘Sources of Materials Property Data and Information’’ by Jack Westbrook
in Volume 20 of the ASM Handbook
1
and to the ASM Directory of Databases.
3
7.1 ASM International
ASM International has emerged as one of the strongest providers of numeric
materials data sources, and those sources are generally in at least two formats
or platforms: hardcopy and disk, usually CD-ROM. As an example, one of the
most extensive sources of high- and low-temperature data for aluminum alloys
has recently been made available through a collaborative effort of ASM and the
Aluminum Association, Inc., in both the book Properties of Aluminum Alloys—
Tensile, Creep, and Fatigue Data at High and Low Temperatures
11
and a search-
able CD of the same title. Other representative data sources from ASM Inter-
national include:
●
ASM Handbook,
12
in hardcopy and CD—20 volumes complete or
available in a specific set covering material properties; the data sets are
available for single workstations and also for local-area network (LAN)
arrangements. Other CDs are available covering heat treatment, testing
and analysis, and manufacturing processes.
●
Alloy Finder CD—contains full alloy records from three ASM hardcopy
reference standards: Woldman’s Engineering Materials,
13
the ASM World-
7 SPECIFIC DATA SOURCES 469
wide Guide to Equivalent Irons and Steels,
14
and the ASM Worldwide
Guide to Equivalent Nonferrous Metals and Alloys.
15
The disk is search-
able by composition as well as designation, so whether the user requires
amplification of an alloy designation or to locate designations within spe-
cific composition ranges, the need is addressed.
●
Alloy Digest on CD—Summaries of recently published data for new and
emerging alloys are compiled periodically on disk as well as being made
available in hardcopy. The advantages include early warning of new ma-
terials; the limitation is the inability to provide consistent formats or data
scope because such are not available for relatively new materials. More
than 4200 data sheets are now available.
●
Binary Phase Diagrams on CD-ROM—The world’s most extensive col-
lection of binary phase diagrams numbering in excess of 4700 is available
on CD, in addition to ASM’s hardcopy publications such as Handbook of
Ternary Alloy Phase Diagrams and the monograph series on specific alloy
groupings.
●
Failure Analysis on CD-ROM—One of the most extensive collections of
data expressly developed for failure analysis is available on searchable
CD-ROM as well as hardcopy.
●
Materials databases on various classes of materials are available from
ASM on disk in various formats including Mat.DB, MAPP, and Rover
search software. The databases are organized and searchable by mechan-
ical and physical property as well as alloy class: steel and stainless steel,
aluminum, composites, copper, magnesium, plastics and polymers nylon,
and titanium, plus a special disk covering corrosion data.
For more detailed information on ASM International’s data sources, the reader
is referred to its Internet web site: www.asminternational.org.
7.2 STN International
STN International is the online worldwide scientific and technical information
network, and one of the most extensive sources of numeric materials property
data.
16
Built and operated by the American Chemical Society at its Chemical
Abstract Service site in Columbus, Ohio, STN International includes about 30
numeric databases, including many developed during the collaboration with the
Materials Property Data Network.
17–19
Of great interest to materials data search-
ers, STN International has the most sophisticated numeric data search software
available anywhere online. Thus the data sources may be searched numerically,
i.e., using numeric values as ranges or with ‘‘greater or less than’’ types of
operators, making it possible to search for alloys that meet required performance
needs.
The disadvantages of using STN International to search for numeric data are
twofold: (a) the search software is keyed to a command system best known to
professional searchers, and engineers and scientists will need patience and some
training to master the technique; and (b) use of the STN International system is
billed via a time and content based cost accounting system, and so a private
account is needed. Outright purchase of databases has not been a policy.
470 SOURCES OF MATERIALS DATA
For those able to deal with those conditions, a number of valuable databases
exists on STN International, including the following representative sources:
●
ALFRAC—Aluminum Fracture Toughness Database (1968–1989 industry
compilation)
●
Aluminium—Aluminum Industry Abstracts (textual; 1868–present)
●
ASMDATA—ASM Materials Databases online version
●
BEILSTEIN—Beilstein Organic Compound Files (1779–1999)
●
COPPERDATA—Copper and Copper Alloy Standards & Data
●
DETHERM—Thermophysical Properties Database (1819–present)
●
DIPPR—AIChE Design Institute Physical Property Data File (1982–
present)
●
GMELIN—GMELIN Handbook of Inorganic Chemistry (1817–present)
●
ICSD—Inorganic Crystal Structure Database (1912–present)
●
NUMERIGUIDE—Property Hierarchy and Directory for Numeric Files
●
MDF—Metals Datafile (1982–1993)
●
PIRA—PIRA and PAPERBASE Database (1975–present)
●
PLASPEC—Plastics Material Selection Database
●
RAPRA—Rubber, Plastics, Adhesives, and Polymer Composites (1972–
present)
For more information on STN International, readers are referred to the website
www.cas.org.
7.3 Internet
As indicated earlier, there are many web sites on the Internet with materials
information content. The challenge is to determine which have useful, reliable,
and relatively easily accessible data. In the interests of readers, we will focus
on guidance on these latter points developed by Fran Cverna, Director of Elec-
tronic and Reference Data Sources at ASM International, who recently produced
and presented a survey of the scope and quality of materials data content found
on Internet web sites.
20
Among the most useful web sites of the several hundred screened by Cverna
and her ASM resources are the following:
www.about.com Internet search engine—search
Materials and Properties
www.nist.gov/public affairs/database.htm NIST—standard reference
database
www.ecn.purdue.edu/MPHO TPRL—thermophysical properties
data
id.inel.gov/shds U.S. government— solvent
database
www.campusplastics.com Campus consortium—plastics
database
7 SPECIFIC DATA SOURCES 471
www.copper.org Copper Development
Association—copper alloys
database
www.brushwellman.com/homepage.htm Brush Wellman—supplier
materials database
www.timet.com/overviewframe.html Timet—supplier materials
database
www.specialmetals.com Special Metals—supplier materials
database
www.cartech.com Cartech—supplier materials
database (compositions)
www.macsteel.com/mdb McSteel supplier materials
database (limited)
www.aluminum.org Aluminum Association
applications—publications’
limited data
Of the sources above, two merit special mention, those being the Internet
search engine site www.about.com and the National Institute for Science and
Technology [(NIST) databases site, a part of the public affairs menu].
The about.com site provides an excellent means of locating materials data
sites and provides a subcategory called ‘‘Materials Properties and Data’’ if you
search for such information. Thirty-two sites are identified, some of which over-
lap the ASM survey, but others are unique to that site in my experience. Many
included in the ASM survey are not included here, so the two are supplementary
in scope. Among the specific types of information accessible via about.com are:
●
Coefficient of thermal expansion
●
Electrical conductivity
●
Electrical resistivity
●
Hardness conversion charts
●
Metal temperature by color
●
Metal weight calculator
●
Periodic table of elements
●
Specific gravity of metals
●
Surface roughness comparison charts
●
Thermal properties
●
Wire gauge conversion tables
●
Utilities to simplify tasks such as conversion charts for units, currency
conversion, glossaries, acronym definitions, etc.
In addition there are links from about.com to many other materials sites, in-
cluding one called aluminum.com that also provides materials data for a variety
of metals, but often without adequate citation and metadata.
472 SOURCES OF MATERIALS DATA
The NIST database site provides direct online access to the highest quality,
carefully evaluated numeric data from the following databases:
●
Standard Reference Data—reliable scientific and technical data extracted
from the world’s literature, assessed for reliability and critically evaluated
●
Ceramics WebBook—evaluated data and access to data centers as well as
tools and resources
●
Chemistry WebBook—chemical and physical property data for specific
compounds
●
Fundamental Physical Constants—internationally recommended values of
a wide range of often used physical constants
●
Thermophysical Properties of Gases for the Semiconductor Industry
To summarize the Internet discussion, there are many sources of numeric
materials data available from Internet sites. It remains for the potential users of
the data, however, to approach each site with caution, look for the pedigree of
the data in terms of quality and reliability, and to make certain that the source
used meets the requirement of the intended use.
Acknowledgments
The contributions of Jack Westbrook (Brookline Technologies) and Fran Cverna
(ASM International) are acknowledged.
REFERENCES
1. J. H. Westbrook, ‘‘Sources of Materials Property Data and Information,’’ in ASM Handbook, Vol.
20, ASM International, Materials Park, OH, 1997, pp. 491–506.
2. J. H. Westbrook and K. W. Reynard, ‘‘Data Sources for Materials Economics, Policy, and Man-
agement,’’ in Concise Encyclopedia of Materials Economics, Policy, and Management, Michael
B. Bever (Ed.), Pergamon, New York, 1993, pp. 35–42.
3. ASM International Directory of Materials Property Databases, ASM International, Materials
Park, OH, published periodically.
4. ASTM International and ANSI/ ISO Standards: Annual Book of ASTM Standards, published
annually, ASTM, Philadelphia; and American National Standards Institute (ANSI) and Interna-
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5. MIL-HDBK-5H, Metallic Materials and Elements for Aerospace Vehicle Structures, U.S. De-
partment of Defense, published periodically.
6. Publications of the Thermophysical Properties Research Center (TPRC, previously known as
CINDAS), Lafayette, IN.
7. ASME Boiler & Pressure Vessel Code, Section 2, Material–Properties, American Society of
Mechanical Engineers, New York, published periodically.
8. Aluminum Standards & Data, 2000, and Aluminum Standards & Data 1998 Metric SI, The
Aluminum Association, Inc., Washington, DC, published periodically.
9. J. H. Westbrook and W. Grattidge, ‘‘The Role of Metadata in the Design and Operation of a
Materials Database,’’ in Computerization and Networking of Materials Databases, ASTM STP
1106, J. G. Kaufman and J. S. Glazman (Eds.), ASTM, West Conshohocken, PA, 1991.
10. J. G. Kaufman, ‘‘Quality and Reliability Issues in Materials Databases,’’ in ASTM Committee
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Reynard (Eds.), ASTM STP 1140, West Conshohocken, PA, 1992, pp. 64–83.
11. J. G. Kaufman, Properties of Aluminum Alloys—Tensile, Creep, and Fatigue Data at High and
Low Temperatures, ASM International, Materials Park, OH, 1999.
12. ASM Handbook, Vol. 1 and 2, Properties and Selection, ASM International, Materials Park, OH,
published periodically.
REFERENCES 473
13. Woldman’s Engineering Alloys, 8th ed., Woldman’s, London, published periodically.
14. Worldwide Guide to Equivalent Irons and Steels, ASM International, Materials Park, OH, pub-
lished periodically.
15. Worldwide Guide to Equivalent Nonferrous Metals and Alloys, ASM International, Materials
Park, OH, published periodically.
16. STNews, a newsletter of STN International, the Worldwide Scientific and Technical Information
Network, Chemical Abstract Services (CAS), a Division of the American Chemical Society,
Columbus, OH, published bimonthly.
17. J. G. Kaufman, ‘‘The National Materials Property Data Network Inc., The Technical Challenges
and the Plan,’’ Materials Property Data: Applications and Access, J. G. Kaufman (Ed.), MPD-
Vol. 1, PVP-Vol. 111, ASME, New York, 1986, pp. 159–166.
18. J. G. Kaufman, ‘‘The National Materials Property Data Network, Inc.—A Cooperative National
Approach to Reliable Performance Data,’’ in Computerization and Networking of Materials Data
Bases, J. S. Glazman and J. R. Rumble, Jr. (Eds.), ASTM STP 1017, West Conshohocken, PA,
1989, pp. 55–62.
19. Jack. H. Westbrook and J. G. Kaufman, ‘‘Impediments to an Elusive Dream,’’ in Modeling
Complex Data for Creating Information, J. E. DuBois and N. Bershon (Eds.), Springer-Verlag,
Berlin, 1996.
20. Fran Cverna, ‘‘Overview of Commercially Available Material Property Data Collections,’’ (on
the Internet), presented at the 2000 ASM Materials Solutions Conference on Materials Property
Databases, ASM International, St Louis, MO, October 10–12, 2000.