Body Jewelry Metals – Titanium

This article is from the Piercing FAQ, by Anne Greenblatt with numerous contributions by others.

2A.1 Titanium

Titanium is an extremely lightweight, elemental metal. The specific
alloy used for body jewelry is 6AL4V (60 parts aluminum, 40 parts
vanadium), specifically 136 grade with extra low interstitial
elements.(4)

“Titanium is the most bio-compatible of all metals due to its total
resistance to attack by body fluids.” (1) Titanium is often used in
permanent surgical implants where the tissue is encouraged to
assimilate the implant; the pores in the metal allow for the tissue to
attach. When titanium is used for body jewelry it should be highly
polished to minimize porosity.

When exposed to air or water, titanium immediately reacts with oxygen
to create a thin, inert oxide layer. While the titanium alloy contains
aluminum and vanadium, the oxide layer does not contain any traces of
either element. (4)

Titanium jewelry is available in a range of colors which are produced
through anodizing, not dyeing. During anodizing, the jewelry is
submerged in an electrolyte solution and voltage is applied. Anodizing
creates an oxide layer on the jewelry. The color results from
refraction of light through the oxide layer, and the thickness of the
layer determines the resulting color. The voltage applied during
anodizing determines the thickness of the oxide. The anodized oxide
eventually wears away, causing the color to fade or change; how long
the process will take depends on the thickness of the oxide layer is
and the amount of friction and wear on the jewelry. Unanodized
titanium is light to medium grey in color.

Black-colored titanium is produced by coating titanium with titanium
carbide through a process called Physical Vapor Deposition
(PVD). Titanium carbide is not biocompatible and does not meet the
specifications established for “implant grade” materials set forth by
the ASTM and ISO. In addition, the coating will not have the smooth a
finish necessary for body jewelry.

References:

(1) Internation Titanium Association, http://www.titanium.net

(2) Reactive Metals Studio Inc.,
http://www.callamer.com/~ezecho/rms/rms.html

(3) TI Specialties, http://www.callamer.com/~ezecho/tispec.html

(4) Gilliam, Brian; Anatometal, Inc. http://www.anatometal.com
Report presented at the Association of Professional Piercings Open
Meeting, May 1998

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