Stability of lamellar structure in a Ti-47.8at%Al alloy

Journal Article · Sat Jan 15 04:00:00 EST 1994 · Scripta Metallurgica et Materialia

DOI:https://doi.org/10.1016/0956-716X(94)90033-7· OSTI ID:231077

Tian, H H; Huang, Z; Chen, C Q ^[1]

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1. Beijing Univ. of Aeronautics and Astronautics (China). Dept. of Materials Science and Engineering

The stability of the lamellar structure is known to be highly structure sensitive. Although some reports have investigated the stability of lamellae in lower aluminum content alloys, few reports have studied the stability of lamellae in near gamma titanium aluminide alloys. The purpose of this paper is to investigate the stability of lamellar structure with different features in Ti-47.8at%Al alloy. The following conclusions were reached: (1) A lamellar structure was obtained in furnace cooled (FC), air cooled (AC) and oil quenched (OQ) samples. As the cooling rate increased, the interlamellar spacing decreased. Thus, the stability of lamellae decreased. The coarsening rate increased with increasing temperature. (2) An {alpha}{sup 2} single phase was obtained in the water quenched (WQ) samples. The lamellae transformed from the {alpha}{sub 2} phase are less stable, and hence have a faster coarsening rate and finer coarse structure compared with the lamellar formed during cooling. (3) Since coarse lamellae nucleate in the {alpha}{sub 2} and {gamma} matrices, more than one habit plane exists, so that the alignment of coarse lamellae is complex. Parallel coarse lamellae with same close-packed plane index form a packet.

• OSTI ID: 231077
• Journal Information: Scripta Metallurgica et Materialia, Journal Name: Scripta Metallurgica et Materialia Journal Issue: 2 Vol. 30; ISSN 0956-716X; ISSN SCRMEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
EXPERIMENTAL DATA
LAMELLAE
MICROSTRUCTURE
MORPHOLOGICAL CHANGES
TITANIUM BASE ALLOYS