Hello schuey:
I was able to find the following information about temperature
influences for strengthening of titanium alloys. I have quoted the
most relelvant parts of each article/webpage, since I couldn't put it
any better in my own words.
If there is more detailed information that you require, please post a
Clarification Request with as much detail as possible on what you are
looking for.
Titanium Alloys – Alpha, Beta and Alpha-Beta Alloys
***************************************************
URL: http://www.azom.com/Details.asp?ArticleID=915
Quotes:
"Alpha alloys- These are non-heat treatable and are generally very
weldable."
"Alpha-Beta alloys- These are heat treatable to varying extents and
most are weldable with the risk of some loss of ductility in the weld
area."
"Beta alloys- Beta or near beta alloys are readily heat treatable,
generally weldable, and offer high strength up to intermediate
temperature levels."
BASIC TITANIUM METALLURGY
*************************
URL: http://www.rti-intl.com/tag/basic.htm
Quotes:
"Alpha alloys cannot be heat-treated to develop higher strength since
they are single-phase alloys."
"Such two-phase titanium [alpha-beta] alloys can be significantly
strengthened by heat treatment quenching from a temperature high in
the alpha-beta range, followed by an aging cycle at a somewhat lower
temperature."
"The high percentage of beta-stabilizing elements in this group of
titanium alloys results in a microstructure that is metastable beta
after solution annealing. Extensive strengthening can occur by the
precipitation of alpha during aging."
Titanium and Titanium Alloys
****************************
URL: http://www.key-to-metals.com/ViewArticle.asp?ID=20
Quotes:
"Another important characteristic of titanium- base materials is the
reversible transformation of the crystal structure from alpha (a,
hexagonal close-packed) structure to beta (b, body-centered cubic)
structure when the temperatures exceed certain level. This allotropic
behavior, which depends on the type and amount of alloy contents,
allows complex variations in microstructure and more diverse
strengthening opportunities than those of other nonferrous alloys such
as copper or aluminum."
The Golden Anniversary of Titanium Biomaterials
***********************************************
URL: http://www.medicaldevicesonline.com/features/story.epml?features.REF=20
"At room temperature, titanium exists in the hexagonal, close-packed
crystal structure known as the alpha phase and transforms to a
body-centred cubic form, the beta phase, at higher temperatures. It is
a well-known metallurgical principle that an alloy that consists of
two separate phases simultaneously should be much stronger than one
that has a single-phase structure. The secret of strengthening the
titanium is, therefore, to arrange for alpha and beta phases to
coexist."
Titanium Alloys
***************
URL: http://www.forging.org/Design/pg4_6.html
Quotes:
"The alpha alloys are designed for resistance to creep at elevated
temperatures, exceeding 535°C (1000°F) in some cases. They are not
heat treatable in the conventional sense but they are annealed after
forging to relieve stresses. The microstructure of alpha is
essentially all alpha phase."
"The alpha-beta alloys are those that include a mixture of alpha and
transformed beta microstructures at room temperatures. They are heat
treatable to very high strengths with a solution treatment and an age
cycle. The widely used Ti-6Al-4V alloy is also the most common forging
alloy."
"The beta alloys are those containing sufficient alloy content to
retain the beta phase to room temperature. Alloys include the more
common Ti-10V2Fe3Al as well as some more highly alloyed grades such as
Ti-13V-11Cr-3Al. These alloys are treatable to high strengths
exceeding those achievable with Ti-6Al-4V. Ti-13V-11Cr-3Al has been
largely superseded by the 10-2-3 grade for forgings."
I hope this information has been of help. :-)
If you need any clarification of the information I have provided,
please ask using the Clarification feature and provide me with
additional details as to what you are looking for. As well, please
allow me to provide you with clarification(s) *before* you rate this
answer.
Thank you.
websearcher-ga
Search Strategy:
"titanium alloys" strengthening
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"titanium alloys" strengthening temperature
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"titanium alloys" strengthening temperature alpha beta
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"titanium alloys" temperature alpha beta "alpha-beta"
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Clarification of Answer by
websearcher-ga
on
04 Nov 2002 12:15 PST
Hi schuey:
Well, I done some more searching, and I've come up with the following
documents. Please forgive me if some of them are slightly "off the
mark" - this is a new topic to me and I may misinterpret certain data.
:-)
Titanium Alloys - Alpha, Beta and Alpha-Beta Alloys
URL: http://www.azom.com/Details.asp?ArticleID=915
Summary: Information is provided on "Crystallographic Forms", "Alpha
Stabilisers", "Beta Stabilisers", "Beta-Isomorphous Elements", and
"Beta-Eutectoid Elements" - each with their own temperature-related
graphic.
Phase diagrams of binary titanium alloys
URL: http://web.met.kth.se/dct/pd/element/Ti.html
Summary: Six execellent phase diagrams for different alloys.
MODELLING OF PHASE EQUILIBRIA IN TI-ALLOYS
URL: http://www.thermotech.co.uk/resources/Ti-alloys.pdf
Summary: Good paper with several diagrams at the end.
Photomicrographic Image Analysis, and the Physical Metallurgy of
Multiphase Titanium Alloys
URL: http://www.engin.umich.edu/class/mse456/Titanium/Titanium_lab-97.html
Summary: Some interesting information in this course outline.
Titanium & its Alloys
URL: http://www.msm.cam.ac.uk/phase-trans/2000/C9/lecture3.pdf
Summary: Good, all-round information
I hope this additional information is of help to you. The following
searches may also turn up other information that I passed over but is
of interest to you.
temperature strength "titanium alloys" alpha beta
://www.google.com/search?hl=en&lr=&ie=ISO-8859-1&safe=off&q=temperature+strength+%22titanium+alloys%22+alpha+beta
"titanium alloys" "phase diagram"
://www.google.com/search?hl=en&lr=&ie=ISO-8859-1&safe=off&q=%22titanium+alloys%22+%22phase+diagram%22
"titanium alloys" metallurgy temperature
://www.google.com/search?hl=en&lr=&ie=ISO-8859-1&safe=off&q=%22titanium+alloys%22+metallurgy+temperature
Thanks.
websearcher-ga
|
