ASTM B481-68(2019)
(Practice)Standard Practice for Preparation of Titanium and Titanium Alloys for Electroplating
Standard Practice for Preparation of Titanium and Titanium Alloys<brk/> for Electroplating
ABSTRACT
This practice describes preparation processes of titanium and titanium alloys to produce adherent electrodeposits of good quality by electroplating. Not all of the processes that have been reported as successful are described, but rather three basic ones that have had the widest use. The purity of reagents and water that shall be used in each process are given. The three processes consist of (1) cleaning by conventional methods such as vapor degreasing, alkaline cleaning, grinding, or blasting, and (2) activating. The first process involves activation by chemical etching which shall be done in the following order of procedure: pickling, rinsing, etching, rinsing, electroplating, and heat treatment. The second process involves activation by electrochemical etching which shall be done by the same procedure as the first process, without the heat treatment step. The third process involves activation by liquid abrasive blasting which shall be done in the following order of procedure: blasting, electroplating, and heat treatment.
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For a specific hazard statement, see 3.1.
1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: B481 − 68 (Reapproved 2019)
Standard Practice for
Preparation of Titanium and Titanium Alloys
for Electroplating
This standard is issued under the fixed designation B481; 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 (´) 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 2. Referenced Documents
1.1 This practice describes processes that have been found 2.1 ASTM Standards:
to be successful in producing adherent electrodeposits of good B343 Practice for Preparation of Nickel for Electroplating
quality on titanium and certain titanium alloys. Not all of the with Nickel
processes that have been reported as successful are described,
but rather three basic ones that have had the widest use. A 3. Reagents
rather complete listing of the published work on electroplating
3.1 PurityofReagents—Allacidsandchemicalsusedinthis
ontitaniumisgiveninthelistofreferenceswhichappearatthe
practice are technical grade.Acid solutions are based upon the
end of this practice.
following assay materials (Warning—Use hydrofluoric acid
1.2 This standard does not purport to address all of the
with extreme care.):
safety concerns, if any, associated with its use. It is the
Hydrochloric acid 37 mass %, density 1.184 g/mL
responsibility of the user of this standard to establish appro- Hydrofluoric acid 60 mass %, density 1.235 g/mL
Hydrofluoric acid 71 mass %, density 1.260 g/mL
priate safety, health, and environmental practices and deter-
Hydrofluoric acid 100 mass %, density 1.0005 g/mL
mine the applicability of regulatory limitations prior to use.
Nitric acid 69 mass %, density 1.409 g/mL
For a specific hazard statement, see 3.1.
3.2 Purity of Water—Use ordinary industrial or potable
1.3 This international standard was developed in accor-
water for preparing solutions and rinsing.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
4. Process No. 1
Development of International Standards, Guides and Recom-
4.1 Cleaning—Remove oil, grease, and other soil by appro-
mendations issued by the World Trade Organization Technical
priate conventional processes such as vapor degreasing, alka-
Barriers to Trade (TBT) Committee.
line cleaning, grinding, or blasting.
This practice is under the jurisdiction of ASTM Committee B08 on Metallic
and Inorganic Coatings and is the direct responsibility of Subcommittee B08.02 on
Pre Treatment. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved April 1, 2019. Published April 2019. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1968. Last previous edition approved in 2013 as B481– 68(2013). DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/B0481-68R19. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B481 − 68 (2019)
4.2 Activating—Activation may be done by chemical or 5. Process No. 2
electrochemical etching or liquid abrasive blasting. It is pos-
5.1 Clean—See 4.1.
sible that all three processes will work equally well on pure
5.2 Electrochemical Etch:
titaniumandallcommonalloys;however,onlythoseforwhich
5.2.1 The following procedure is suitable for commercially
each process has been demonstrated to be successful are given
pure titanium and 4Al-4Mn alloy. The adhesion produced is
here. The suitability of a process for an alloy not listed should
purely mechanical but sufficient to pass a bend test and heating
be experimentally determined before committing production
in a gas flame.
parts.
5.2.2 Pickle—Immerse in the following solution at room
4.2.1 Chemical Etch:
temperature until red fumes are evolved:
4.2.1.1 The following procedure is suitable for commer-
HF (60 mass %) 1 volume and
cially pure titanium and for 6Al-4V, 4Al-4Mn, and 3Al-5Cr.
HNO (69 mass %) 3 volumes
4.2.1.2 Pickle—Immerse in the following solution, at room
5.2.3 Rinse.
temperature, until red fumes are evolved:
5.2.4 Etch—Immerse in the following solution and make
HF (60 mass %) 1 volume and
anodic, raising the current above the operating value until local
HNO (69 mass %) 3 volumes
chemical attack of the metal is stopped as evidenced by the
4.2.1.3 Rinse.
cessation of gassing. Then reduce the current to the operating
4.2.1.4 Etch—Immerse in the following aqueous solution 2
value and etch anodically at 5.4 A/dm for 15 to 30 min.
for20min(Notethataspecialformulationisrecommendedfor
HF (anhydrous) 15 mass %
3Al-5Cr alloy).
H O 6 mass %
Ethylene glycol 79 mass %
Standard 3Al-5Cr
Temperature 55 to 60 °C
Na Cr O ·2H O 250 g/L 390 g/L
2 2 7 2
HF (60 % mass) 48 mL/L 25 mL/L
5.2.4.1 The formulation in 5.2.4 is equivalent to the follow-
Temperature 82 to 100 °C 82 to 100 °C
ing volumetric formulation.
NOTE 1—For platinum electroplating on commercially pure titanium,
HF (71 mass %) 19 volumes and
etching may be done by immersion for 5 min in hot (94 °C min)
Ethylene glycol 81 volumes
concentrated hydrochloric acid followed by rinsing and platinum electro-
5.2.4.2 The water content must not be too high; therefore,
plating (1).
less concentrated grades of hydrofluoric acid cannot be substi-
4.2.2 Rinse.
tuted for the 71 % grade. The solution or part should be mildly
4.2.3 Electroplate—Electroplate with chromium, with cop-
agitated. The cathodes may be carbon, nickel, copper, or other
per from an acid bath, or with nickel from either a Watts or
materials not attacked by the so
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