Hydrogen transport behavior of Timetal-21S alloy

Journal Article · Mon Nov 01 00:00:00 EST 1993 · Scripta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-716X(93)90117-B· OSTI ID:5786778

Sankaran, S N; Herrmann, R K ^[1]; Clark, R K; Outlaw, R A ^[2]

---

1. Analytical Services and Materials, Inc., Hampton, VA (United States)
2. NASA, Hampton, VA (United States). Langley Research Center

Ti-15Mo-2.7Nb-3Al-0.2Si (Timetal-21S), a metastable [beta]-titanium alloy, is a candidate material for titanium matrix composite structures in hydrogen-fueled hypersonic planes because of its excellent formability and adequate mechanical properties in the 500--800 C temperature range. The alloy is strengthened through the precipitation of fine [alpha] particles in the [beta] matrix. The mechanical properties and microstructures are controlled by a solutionizing/aging heat treatment. A major concern in using titanium alloys in hydrogen service is the embrittlement caused by the precipitation of hydrides. It is believed that the large solubility of hydrogen in the [beta]-phase would preclude the precipitation of hydrides in Beta titanium alloys, especially at low hydrogen pressures. However, depending on the hydrogen content, a shift in the ductile/brittle transition temperatures to levels much higher than room temperature has been reported for Timetal-21S alloy. The objective of the present investigation was to determine the hydrogen transport characteristics of the Timetal-21S alloy at moderate pressures up to 6,667 Pa (50 torr) and at temperatures from 400 C to 800 C. A microbalance technique, also referred to as thermogravimetric analysis (TGA), for sorption measurements under ultrahigh vacuum (UHV) conditions was the primary method in this work.

• OSTI ID: 5786778
• Journal Information: Scripta Metallurgica et Materialia; (United States), Vol. 29:9; ISSN 0956-716X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
HYDROGEN EMBRITTLEMENT
HYDROGEN
ATOM TRANSPORT
MOLYBDENUM ALLOYS
NIOBIUM ALLOYS
TITANIUM BASE ALLOYS
SILICON ADDITIONS
ALLOYS
ELEMENTS
EMBRITTLEMENT
NEUTRAL-PARTICLE TRANSPORT
NONMETALS
RADIATION TRANSPORT
SILICON ALLOYS
TITANIUM ALLOYS
360105* - Metals & Alloys- Corrosion & Erosion