Mechanical behaviour of Al sub 3 Ti intermetallic and L1 sub 2 phases on its basis

• Published in: Intermetallics 2001-09, Vol.9 (9), p.839-845
• Main Authors: Milman, Y V, Miracle, D B, Chugimova, S I, Voskoboinik, L, Korzhova, N P, Legkaya, T N, Podrezov, Y N
• Format: Article
• Language: English
• ISSN: 0966-9795

The mechanical properties of trialuminide intermetallic Al sub 3 Ti and L1 sub 2 phases Al sub 61 Cr sub 12 Ti sub 27 and Al sub 66 Mn sub 11 Ti sub 23 were investigated by an indentation technique. The stress-strain curves were obtained using 9 pyramidal indenters with various angles of sharpening. The hot hardness was measured in the temperature range 20-900 deg C, and the plasticity characteristic delta sub H was determined during indentation. Bending tests were used to determine Young's modulus, and compression tests were carried out as well. The transition of the crystalline structure from tetragonal Al sub 3 Ti to cubic L1 sub 2 of Cr- and Mn doped intermetallics was accompanied by a decrease of hardness over the full range of the investigated temperatures. The temperature dependence of hardness is weak for all investigated intermetallics. The work hardening and mechanism of deformation are discussed. Plasticity characteristic delta sub H for the L1 sub 2 phases is higher than for Al sub 3 Ti and is close to the critical value delta sub H = 0.9, which is correlated with bulk ductility, that gives some hope to obtain L1 sub 2 phases based on Al sub 3 Ti with room temperature ductility.