Effect of growth rate on microstructure parameters and microhardness in directionally solidified Ti-49A1 alloy

摘要

Intermetallics Ti-49A1 (at.%) alloy was directionally solidified with different growth rates (V= 5 μm/s-30 (μm/s) at a constant temperature gradient (G = 12.1 K/mm) by using a Bridgman type directional solidification furnace. The primary dendritic spacing (λ), interlamellar spacing (λ_L), and microhardness (HV) were measured. Effect of V on HV, I and λ_L was experimental investigated. The dependencies of V, λ_L and HV on the growth rate were determined by using linear regressing analysis. According to the result, the values of V and λ_L decrease with the increasing of V, and the values of HV increase with the increasing of V and with the decreasing of V and λ_L. The results were compared with previous similar experimental results for TiAl-based alloys.