ASTM B481-68(1997)
(Practice)Standard Practice for Preparation of Titanium and Titanium Alloys for Electroplating
Standard Practice for Preparation of Titanium and Titanium Alloys for Electroplating
SCOPE
1.1 This practice describes processes that have been found to be successful in producing adherent electrodeposits of good quality on titanium and certain titanium alloys. Not all of the processes that have been reported as successful are described, but rather three basic ones that have had the widest use. A rather complete listing of the published work on electroplating on titanium is given in the list of references which appear at the end of this practice.
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use . For a specific hazard statement, see 3.1.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superceded and replaced by a new version or discontinued. NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information. Contact ASTM International (www.astm.org) for the latest information.
Designation: B 481 – 68 (Reapproved 1997)
Standard Practice for
Preparation of Titanium and Titanium Alloys
for Electroplating
This standard is issued under the fixed designation B 481; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
Full utilization of the light weight and high strength of titanium is prevented by the tendency it has
to gall and seize and by its lack of corrosion resistance at elevated temperatures. Frequently these
limitations can be overcome by electrodepositing upon the titanium a metal with satisfactory
properties. Titanium is an active metal that rapidly forms an adherent oxide coating in the presence of
oxygen and water. This coating prevents the application of adherent electrodeposits by the more
familiar preparative processes. For this reason, the special processes described in this practice were
developed.
1. Scope
Hydrochloric acid 37 mass %, density 1.184 g/mL
Hydrofluoric acid 60 mass %, density 1.235 g/mL
1.1 This practice describes processes that have been found
Hydrofluoric acid 71 mass %, density 1.260 g/mL
to be successful in producing adherent electrodeposits of good
Hydrofluoric acid 100 mass %, density 1.0005 g/mL
Nitric acid 69 mass %, density 1.409 g/mL
quality on titanium and certain titanium alloys. Not all of the
processes that have been reported as successful are described,
Caution—Use hydrofluoric acid with extreme care.
but rather three basic ones that have had the widest use. A
3.2 Purity of Water—Use ordinary industrial or potable
rather complete listing of the published work on electroplating
water for preparing solutions and rinsing.
on titanium is given in the list of references which appear at the
4. Process No. 1
end of this practice.
1.2 This standard does not purport to address all of the
4.1 Cleaning—Remove oil, grease, and other soil by appro-
safety concerns, if any, associated with its use. It is the
priate conventional processes such as vapor degreasing, alka-
responsibility of the user of this standard to establish appro-
line cleaning, grinding, or blasting.
priate safety and health practices and determine the applica-
4.2 Activating—Activation may be done by chemical or
bility of regulatory limitations prior to use. For a specific
electrochemical etching or liquid abrasive blasting. It is pos-
hazard statement, see 3.1.
sible that all three processes will work equally well on pure
titanium and all common alloys; however, only those for which
2. Referenced Documents
each process has been demonstrated to be successful are given
2.1 ASTM Standards:
here. The suitability of a process for an alloy not listed should
B 343 Practice for Preparation of Nickel for Electroplating
be experimentally determined before committing production
with Nickel
parts.
4.2.1 Chemical Etch:
3. Reagents
4.2.1.1 The following procedure is suitable for commer-
3.1 Purity of Reagents—All acids and chemicals used in
cially pure titanium and for 6Al-4V, 4Al-4Mn, and 3Al-5Cr.
this practice are technical grade. Acid solutions are based upon
4.2.1.2 Pickle—Immerse in the following solution, at room
the following assay materials:
temperature, until red fumes are evolved:
HF (60 mass %) 1 volume and
HNO (69 mass %) 3 volumes
This practice is under the jurisdiction of ASTM Committee B-8 on Metallic and
4.2.1.3 Rinse.
Inorganic Coatings and is the direct responsibility of Subcommittee B08.02 on
4.2.1.4 Etch—Immerse in the following aqueous solution
Substrate Preparation.
for 20 min (Note that a special formulation is recommended for
Current edition approved July 16, 1968.
Annual Book of ASTM Standards, Vol 02.05. 3Al-5Cr alloy).
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued. NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information. Contact ASTM International (www.astm.org) for the latest information.
B 481 – 68 (1997)
Standard 3Al-5Cr HF (anhydrous) 15 mass %
Na Cr O ·2H O 250 g/L 390 g/L H O 6 mass %
2 2 7 2 2
HF (60 % mass) 48 mL/L 25 mL/L Ethylene glycol 79 mass %
Temperature 82 to 100°C 82 to 100°C Temperature 55 to 60°C
5.2.4.1 The formulation in 5.2.4 is equivalent to the follow-
NOTE 1—For platinum electroplating on commercially pure titanium,
etching may be done by immersion for 5 min in hot (94°C min)
ing volumetric formulation.
concentrated hydrochloric acid followed by rinsing and platinum electro-
HF (71 mass %) 19 volumes and
plating (6)
Ethylene glycol 81 volumes
4.2.2 Rinse.
5.2.4.2 The water content must not be too high; therefore,
4.2.3 Electroplate—Electroplate with chromium, with cop-
less concentrated grades of hydrofluoric acid cannot be substi-
per from an acid bath, or with nickel from either a Watts or
tuted for the 71 % grade. The solution or part should be mildly
sulfamate bath, or deposit nickel in an autocatalytic bath. If a
agitated. The cathodes may be carbon, nickel, copper, or other
deposit of some metal other than these three is desired, first
materials not attacked by the solution.
apply a nickel coating with a minimum thickness of 1 μm
5.2.4.3 Remove the part while the current is still on.
followed by the desired final metal.
5.2.4.4 Excessive current densities will produce electropol-
4.2.4 Heat Treat:
ishing and inadequate current densities will permit local
4.2.4.1 The adhesion of the electrodeposit is mechanical
chemical attack. Both conditions will result in lack of adhesion
and, therefore, although of a relatively high order of magni-
of the electroplating.
tude, it may be less than adequate. If a higher degree of
5.2.5 Rinse.
adhesion is desired, use nickel as an intermediate coating and
5.2.6 Electroplate—Electroplate with copper from an acid
heat treat. This causes interdiffusion of the nickel and titanium
bath or copper from a cyanide bath preceded by a cyanide
and produces a met
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.