A study of mechanical properties and microscopic stress of a two-phase TiAl-based intermetallic alloy

In order to study the effects of the microstructures on the mechanical properties and internal stresses of a TiAl-based alloy, a series of fine duplex microstructures with different volume ratios of equaxied gamma grains and gamma + alpha (2) lath colonies of a TiAl-based alloy were produced by isothermal forging and heat treatment. Tensile tests were carried out at room temperature, and X-ray elastic constants were determined experimentally. The mechanical state of a given phase in the alloy, induced by uniaxial tensile loading, was characterized by X-ray diffraction. It was found that the macroscopic mechanical properties and microscopic stresses strongly depend on the micro structures, and there is a difference between the macroscopic properties and the microscopic properties, and the reasons are discussed. (C) 2001 Elsevier Science B.V, All rights reserved.