National Institute for Materials Science

Citizen Watch Company, Ltd.

Toshimitsu Tetsui

Takayuki Ogawa

Masahiro Satoh

The present invention provides a TiAl-based alloy, including: Al: 41 to 43 at %; Fe: 0 to 2.5 at %; Ni: 0 to 2.5 at %; Mo: 0 to 2.0 at %; W: 0 to 2.0 at %; Cr: 0 to 4.5 at %; Mn: 0 to 5.5 at %; V: 0 to 10 at %; Nb: 0 to 10 at %; C: 0.3 to 0.7 at %; and a remainder consisting of Ti and inevitable impurities, in which an alloy element parameter 'P=(41.5−Al)/3+Fe+Ni+Mo+W+0.5 Cr+0.4 Mn+0.2 V+0.2 Nb—C' is in a composition range of 1.1 to 1.9, and the TiAl-based alloy has a microstructure consisting of a γ phase of 5 to 30 area %, a β phase of 0.5 to 5 area %, and a lamellar structure occupying a remaining part.

Hot-forged tial-based alloy, method for producing same, and uses for same

A titanium alloy of the present invention includes aluminum at a ratio of 28.0 at % or more and 38.0 at % or less, iron at a ratio of 2.0 at % or more and 6.0 at % or less, and titanium and inevitable impurities as the balance or includes aluminum at a ratio of 28.0 at % or more and 38.0 at % or less, manganese at a ratio of 4.0 at % or more and 8.0 at % or less, and titanium and inevitable impurities as the balance. Further, the titanium alloy of the present invention may include silicon at a ratio of 0.3 at % or more and 1.5 at % or less.

Titanium alloy and method of manufacturing material for timepiece exterior part

Provided is a hot-forged TiAl-based alloy of the present invention containing 40 to 45 atom % of Al and additive elements in the following composition ratio (A) or (B), and the balance Ti with inevitable impurities: (A) Nb: 7 to 9 atom %, Cr: 0.4 to 4.0 atom %, Si: 0.3 to 1.0 atom %, and C: 0.3 to 1.0 atom %; and (B) at least one of Cr: 0.1 to 2.0 atom %, Mo: 0.1 to 2.0 atom %, Mn: 0.1 to 4.0 atom %, Nb: 0.1 to 8.0 atom %, and V: 0.1 to 8.0 atom %. The TiAl-based alloy is characterized by having a fine structure of densely arranged lamella grains that are laminated alternately with a TiAl phase (&#x3b1;2-phase) and a TiAl phase (&#x3b3;-phase) and have an average grain size of 1 to 200 &#x3bc;m.

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Tsukuba, Japan

Toshimitsu Tetsui