Effect of Heat Treatment Conditions on Microstructure and Fracture Toughness of a Cast Ti-Al Alloy

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Ti-45.5Al-2Cr-4Nb-0.4B alloy was cast by vacuum arc melting at high purity Ar atmosphere using high purity sponge Ti, granular Al (99.99%), flake Nb (99.9%), lump Cr (99.9%) and TiB2 (99.5%) and subsequently heat-treated to obtain a couple of microstructures, i.e. lamellar and near γ. The heat treatment consisted of annealing at a high temperature (1200 ~ 1330oC) of different phase fields for 24 hrs and stabilizing at 900oC for 4 hrs followed by air cooling. Fracture toughness was measured on the specimens with different microstructures at room temperature. The value of KQ of specimen with fully lamella structure was obtained as 18.68 MPa √m, much higher than that of specimen with near γ structure (11.84 MPa √m). It was also revealed that the KQ value was decreased as the annealing temperature decreased.

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Periodical:

Advanced Materials Research (Volumes 26-28)

Edited by:

Young Won Chang, Nack J. Kim and Chong Soo Lee

Pages:

189-192

Citation:

T. K. Ha and J. Y. Jung, "Effect of Heat Treatment Conditions on Microstructure and Fracture Toughness of a Cast Ti-Al Alloy", Advanced Materials Research, Vols. 26-28, pp. 189-192, 2007

Online since:

October 2007

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$38.00

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